- Email: [email protected]
Effects of hypobaric and temperature-dependent storage on headspace aroma-active volatiles in common squid miso
Food Research International 44 (2011) 739–747
Contents lists available at ScienceDirect
Food Research International j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / f o o d r e s
Effects of hypobaric and temperature-dependent storage on headspace aroma-active volatiles in common squid miso Anupam Giri, Kazufumi Osako, Toshiaki Ohshima ⁎ Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo 108-8477, Japan
a r t i c l e
i n f o
Article history: Received 10 November 2010 Accepted 5 January 2011 Keywords: Aroma active compounds Squid miso Hypobaric storage
a b s t r a c t The purpose of this study was to elucidate the effects of storage at hypobaric (10 kPa) atmosphere at room temperature (25 °C) and at a low temperature of 10 °C at atmospheric pressure on the headspace volatiles of miso prepared from common squid meat during 270 days of storage. Based on the odor active values of the volatiles detected, 2-methylpropanal, 3-methylbutanal, 3-methyl-1-butanol, n-ethyl decanoate, 2,3-butanedione, dimethyl disulfide, methional, and 2-methyl butanoic acid were identified as key aroma compounds in squid miso. Low-temperature storage appeared to retard volatile compound formation and extent the shelf life. Hypobaric storage induced a significant reduction in lipid oxidation products, particularly aldehydes and ketones. The contents of sulfur-containing compounds and acids were significantly low; however, esters had relatively higher levels in hypobaric conditions. Production of furans and their derivatives were also found to be controlled by hypobaric storage. Therefore, hypobaric storage can be considered as an effective means of preserving squid miso and related fish paste products to prolong shelf-life in order to maintain aroma attributes. © 2011 Elsevier Ltd. All rights reserved.
1. Introduction The fermented fish meat product fish miso is a promising paste product, for which koji (rice malt) is used as a starter (Giri, Osako, & Ohshima, 2009a). Several investigations of its taste components, nutritional status, and aroma profile have been conducted for the finished product and also during fermentation (Giri, Osako, & Ohshima, 2009b; Giri, Osako, & Ohshima, 2010; Giri et al., 2009a). However, its storage stabilities in terms of volatile compound formation have not been studied previously. Fish miso is considered a live product because of its active enzymes that mostly originate from koji inoculated with Aspergillus oryzae and from fish meat. The volatile profile of fish miso thus appears to be greatly affected by its storage conditions. Therefore, there is necessity to develop an effective means of preserving fish miso to prolong shelf-life to maintain the aroma attributes that are qualitatively and quantitatively appreciated by consumers. Hypobaric storage, a patented method developed by Burg (1967), is an emerging storage technique to extend the useful life of fresh fruits, vegetables, cut flowers, cuttings, potted plants, meat, poultry, fish, shrimp, and other metabolically active matter by lowering atmosphere pressure in a closed chamber. This can quickly remove heat, reduce the oxygen level, and expel harmful gas. It has been reported that fruits exposed to brief periods of low pressure as well as hypoxic storage have reduced postharvest decay (Pesis & Avissar, 1989) and improved fruit
⁎ Corresponding author. Tel.: + 81 3 5463 0613. E-mail address: [email protected] (T. Ohshima). 0963-9969/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodres.2011.01.025
quality (Pesis, 1994) compared to untreated fruit. Sensory analysis indicated that fruit treated with hypoxia had enhanced aroma/flavor. This improvement in flavor was undoubtedly due to increased concentrations of aroma/flavor volatiles induced by exposure to hypoxia (Pesis, 1994). However, no research has been reported on the hypobaric storage of fermented fish paste-like products. Thus, the present study was conducted to evaluate the effect of hypobaric pressure (HT-Hypobaric), atmospheric room temperature (HT), and low temperature (LT) on the headspace volatiles of matured fish miso prepared from common squid meat during storage. In vitro analysis of the substrate specificities of several koji enzymes under different storage conditions was also performed for better understanding. 2. Materials and methods 2.1. Materials Common squid (Todarodes pacificus) with an average body weight of 311 ± 18 g and average mantle length of 24.7 ± 0.5 cm were caught by trawl nets and set nets off the shores of Nagasaki Prefecture. The squid were stored at −50 °C for a month until use for the production of fish miso. 2.2. Chemicals All of the volatile standards used for identification and other analytical purposes were of GC-analytical grade and were purchased from Tokyo Chemical Industry (Tokyo, Japan).
740
A. Giri et al. / Food Research International 44 (2011) 739–747
2.3. Preparation of koji Dried and polished koshihikari rice (Oryza sativa, produced in Niigata Prefecture, Japan) was soaked in fresh water for 12 h at room temperature and was steamed at 90 °C for 1 h. After cooling at room temperature to 35 °C, the rice was inoculated with 0.5% (w/w) koji mold (M1 mold, pure strain of A. oryzae; Nihon Jozo Kogyo, Tokyo, Japan) and incubated at 35 °C for 48 h, and the obtained malt-rice was used as koji. 2.4. Preparation of fermented fish and bean pastes Squid were skinned, and mantle meat was used for paste preparation. After grinding separately with a model M-22 grinder (Nantsune Tekko, Osaka, Japan), the ground meat was put into an aluminum-coated heatstable polyvinylchloride pouch (210 × 150+ 45 mm; Sansyo Co. Ltd., Tokyo, Japan), vacuum-sealed, and then steam-heated at 90 °C for 1 h. Portions were then filter pressed at 2 MPa to achieve moisture contents between 50 and 55%, using a model KS-1 filter press (Komagata Kikai Seisakusho, Tokyo, Japan). The obtained dehydrated meat was used as unwashed meat. Other portions were washed by five volumes of fresh water three times before pressing to obtain washed meat. Squid meat, koji, and salt were mixed with a grinder at the ratio of 5:5:1 by wet weight. About 3 kg of squid paste was packed into a 5-L opaque plastic container (Sansyo Co. Ltd., Tokyo, Japan) tightly sealed with a cap and fermented at a temperature between 25 and 30 °C for 90 days. The contents of each container were mixed thoroughly once a month. The prepared material was called matured squid miso. 2.5. Storage conditions Ninety days fermented matured squid miso was further stored at three different storage conditions. Storage was at atmospheric room temperature (HT-Atm, 25 °C) or atmospheric low temperature (LT-Atm, 10 °C). Hypobaric storage (HT-Hypobaric) was in a container (30 × 30 × 15 cm3) equipped to maintain low pressure (10 kPa) at 25 °C. Samples were stored for a period of 270 days, and small samples were removed for further analysis at 0, 45, 90, 180, and 270 days. Day 0 was counted at the end of the initial 90 days of fermentation. 2.6. Isolation of volatiles using a Tenax TA trap and gas chromatographic analysis Samples (3 g) with an internal standard were placed in 500-mL dual-necked round bottom flasks that were placed over a hot water bath maintained at 75 °C. Nitrogen gas of high purity (99.999%) was passed through the smaller neck of the flask at a flow rate of 100 mL/min, and headspace volatiles emanating from the sample were trapped for 30 min in a glass-fritted absorption trap (4 mm I.D., 6 mm O.D., and 4.5 in. length; Supelco, Belleonte, PA, USA) filled with 175 mg of 60/88 mesh Tenax TA (Supelco) fitted to a bigger neck by a connector. Dry nitrogen purge was performed for 10 min at a flow rate of 50 mL/min in a direction opposite to the isolation to remove residual moisture. The Tenax TA trap was preconditioned at 300 °C for 30 min with nitrogen gas at 50 mL/min by a Model 10 tube conditioner (Dynatherm Analytical Instruments INC., Kelton, PA, USA) before each sampling of the volatile compounds. The dry-purged tube with trapped volatiles was placed in a Model ACEM 900-FF/EPC automated thermal desorption system (CDS Analytical INC., PA, USA). Volatiles trapped in the dry-purged Tenax TA tube were desorbed for 3 min at a temperature of 300 °C and were introduced into a capillary column in a narrow-band plug through a short path transfer line (0.5 m inert capillary column maintained at 250 °C). Analysis of volatiles was performed on a Shimadzu model 14A gas chromatograph (Kyoto, Japan) equipped with a Suplecowax™
10 fused silica capillary column (0.32 mm I.D. × 60 m, 0.25 μm film thickness, Supelco). High purity (99.999%) helium was used as a carrier gas at a flow rate of 1.5 mL/min. The column temperature was maintained at 40 °C for 3 min and subsequently programmed to 200 °C at a rate of 3 °C/min. Injector and detector temperatures were set at 250 °C. 2.7. Conditions of gas chromatography–mass spectrometry Analyses of the mass spectrum of volatile compounds separated by a Suplecowax™ 10 fused silica capillary polar column (0.25 mm I.D. × 60 m, 0.25 μm film thickness; Supelco) were performed on a Hewlett Packard 5890 Series II gas chromatograph equipped with a Tekmar 7000 headspace autosampler (Cincinnati, OH, USA) and an ion source from Automass (JEOL, Japan). The ionization energy, scan range, and scan rate applied in the analysis were 70 eV, 40–350 m/z, and 500 m/s, respectively. The column temperature was initially maintained at 40 °C for 3 min and subsequently increased to 200 °C at a rate of 3 °C/min. 2.8. Identification and quantification of volatile compounds The volatiles were identified on the basis of comparisons of their mass spectra and relative abundances with Wiley spectral libraries (ver. 5). The identity of each compound was further confirmed by comparing its mass spectra, linear retention index (LRI), and retention time with that obtained for an authentic standard. Kovats retention indices (RIs) were determined for both SPME-GC-FID and GC-MS by using a series of n-hydrocarbons (C5–C24) and comparing them with those reported previously (Giri et al., 2010). Quantification of the volatiles was conducted using standard curves obtained from each compound from at least five different concentrations in methanol. The levels of the volatile compounds were normalized by 2,4,6-trimethyl pyridine equivalents by assuming all of the response factors were one. Ten microliters of 2,4,6-trimethyl pyridine of 1 mg/mL was introduced into the 3-g sample just before the volatile isolation process. 2.9. Calculation of odor activity values The odor activity values (OAVs) were determined by dividing the concentration of the odorant in the samples by the mean values of its estimated orthonasal threshold. The threshold values as well as odor descriptions estimated in our previous work were used in the present study (Giri et al., 2010). 2.10. In vitro enzyme assays under different storage conditions Assays for three different enzymes, protease, α-amylase, and lipase, were investigated under different storage conditions identical to miso storage. For these assays, however, two additional storage conditions were adopted for further investigation including LT-Atm (10 °C at atmospheric pressure) and LT-Hypobaric (25 °C at 10 kPa). Crude enzymes from the freshly prepared A. oryzae-fermented rice malt koji for 48 h were extracted with phosphate-buffered saline (100 mM, pH 7.0) at 1:10 w/v ratio. A crude enzyme fraction extracted from koji was appropriately added to several soluble substrates. Sampling was performed at an interval of 6 h during the 60-h storage period. For protease, amylase, and lipase assays, 1% casein, 2.0% (w/v) soluble starch in 0.05 M citric acid buffer (pH 4.8), and 1 × 10−3 M 1-naphthyl acetate were used as substrates, respectively. After sampling at different fermentation periods, activity was measured as described below. 2.10.1. Protease activity After sampling, the reaction was arrested by adding 1 mL of 10% TCA. After centrifuging the reaction mixture at 3000 ×g for 15 min at
A. Giri et al. / Food Research International 44 (2011) 739–747
4 °C, supernatant was collected and further mixed with 5 mL of 0.44 M Na2CO3 and 1 mL of 3-fold diluted Folin–Ciocalteau reagent. The resulting solution was incubated for 30 min at 30 °C, and absorbance at 660 nm was determined.
741
2.10.2. α-Amylase activity The reaction was terminated by the addition of 100 μL of 3,5dinitrosalicylic acid (DNS) reagent and heated in boiling water for 10 min. The reducing groups released from starch catalyzed/reduced
Table 1 Identification, threshold and odor descriptions of volatiles detected in squid miso during storage. RIa
Identificationb Threshold Odor descriptionc (μg/L)c
Peak Volatile compounds no.
Aldehydes 1 Acetaldehyde 2 2-Methylpropanal 4 2-Methylbutanal 5 3-Methylbutanal 14 Hexanal 27 Heptanal 33 2-Hexenal (Z) 37 4-Heptenal
692 814 912 915 1091 1199 1235 1255
MS, MS, MS, MS, MS, MS, MS, MS,
RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std
25.1 1.5 1.0 0.2 5.0 2.9 19.2 4.2
Apple skin Nutty, malty Nutty, almond Almond, nutty Fishy, grassy Dry fish, green Stink bug Biscuit, creamy
Esters 3 9 13 17 20 23 36 40
44
Octanal
1298 MS, RI, Std
0.6
Orange peel
42
59 70 76
Nonanal 2,4-Heptadienal (E,Z) 2,4-Heptadienal (E,E)
1405 MS, RI, Std 1483 MS, RI, Std 1508 MS, RI, Std
1.1 94.8 15.4
Green, tallowy Fried, fatty Fatty, hay
45 53 63 78
Strong alcoholic Plastic, pungent Green apple Solvent like Green Fragrant Burnt, meaty Alcoholic Fusel oil Rancid, pungent Fatty, fruity Green, pungent Winey, whisky Musty odor Pleasant Mashroom, herb Green, plastic Herbaceous
Peak Volatile compounds no.
1283 MS, RI, Std
75.0
Berry note, fruity
1303 1341 1444 1649
MS, RI, MS, RI, MS, RI, MS, RI,
Std Std Std Std
19.9 2.0 19.4 5.0
Fruity, sweet Banana, fruity Sweet, soapy Grape
Aromatic compounds 18 Ethyl benzene 22 p-Xylene 25 o-Xylene 28 Cymene 30 Propyl benzene 41 p-Cymene 73 Benzaldehyde 80 Ethyl benzoate 85 4-Ethyl benzaldehyde 87 Ethylphenyl acetate 88 2-Phenylethyl acetate 89 Benzyl alcohol 90 Phenylethyl alcohol 92 Phenol 93 4-Ethylguaiacol 94 4-Ethylphenol
1126 1139 1191 1209 1215 1274 1544 1683 1728 1799 1834 1893 1931 2025 2046 2195
MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI,
Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
2205.3 68.6 450.2 6.5 177.1 5.0 750.9 55.6 123.2 155.6 249.6 2546.2 564.2 5501.2 89.3 1010.1
Ethereal, floral Cold meat, oily Geranium, oily Strong aromatic Moth-ball like Gasoline, spicy Bitter almond Chamomile Fruity, anisic Honey, rose Honey, rosy Sweet floral Honey, rose Medicinal Clove, spicy Shoe polish
Sulfur 12 57 66
1081 MS, RI, Std 1389 MS, RI, Std 1476 MS, RI, Std
1.1 45.0 0.5
Cooked cabbage Cocoa, green Baked potato
1695 MS, RI, Std 1735 MS, RI, Std
51.2 856.1
950,000.0 8505.7 1259.9 6505.3 4125.0 459.2 358.1 820.5 16.0 4.0 1508.2 150.3 7.6 75.2 125.1 65.2 89.2 547.1 5.7 35.0 232.0
Green, grassy Mashroom Brandy nuance
61 64
2-Hexen-1-ol (Z) 1-Octen-3-ol
1422 MS, RI, Std 1460 MS, RI, Std
359.4 1.5
Walnut, medicinal 84 Mushroom, fishy 86
65 69 72 74 75 79
Heptanol 2-Ethyl hexanol 2-Nonanol Octanol 2,3-Butanediol (meso) 1-Nonanol
1465 1497 1525 1566 1593 1671
MS, MS, MS, MS, MS, MS,
RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std
5.5 25,482.2 8598.8 125.9 95.1 45.5
Fresh, light green Green rosy Coconut, waxy Herbaceous, fatty Fruity, onion Dusty, oily, green
Nitrogen containing compounds 47 2,3-Dimethylpyrazene 62 2,3,5-Trimethylpyrazine 68 Tetramethylpyrazine 91 2-Acetylpyrrole
1322 1438 1487 1993
MS, MS, MS, MS,
RI, Std RI, Std RI, Std RI, Std
2225.3 350.1 2525.0 58,585.3
Green, nutty Bread, burnt Fermented soy Herbal, nutty
Acids 82 2-Methylbutanoic acid
1690 MS, RI, Std
0.7
83
1693 MS, RI, Std
1560.9
b c
3-Methylbutanoic acid
MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI,
Fruity, buttery Banana, pear note Pineapple note Fruity, sweet Banana, fresh Orange, fruity Fruity, strawberry Sweet, apricot
RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI RI, Std RI, Std RI, Std
a
890 1026 1083 1117 1133 1143 1241 1272
5.0 25.0 58.0 30.1 1.6 5.9 2.3 15.0
924 1064 1095 1103 1131 1169 1181 1214 1223 1226 1237 1263 1318 1324 1327 1330 1337 1339 1347 1367 1402 1417
MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS,
Identification Threshold Odor description (μg/L) Std Std Std Std Std Std Std Std
Alcohols 6 Ethanol 11 1-Propanol 15 3-Methyl-2-butanol 16 2-Methylpropanol 19 3-Pentanol 24 1-Butanol 26 1-Penten 3-ol 29 3-Hexanol 31 2-Methyl-1-butanol 32 3-Methyl-1-butanol 34 2-Hexanol 39 1-Pentanol 46 3-Methyl-1-pentanol 48 2-Ethyl-1-butanol 49 Cyclopentanol 50 2-Heptanol 51 2-Penten-1-ol (E) 52 3-Methyl-3-buten-1-ol 55 1-Hepten-3-ol 56 Hexanol 58 3-Octanol 60 2-Hexen-1-ol (E)
Ethyl acetate 2-Methylpropyl acetate Butyl acetate Isobutyl isobutyrate Isoamyl acetate Ethyl pentanoate Ethyl hexanoate 3-Methylbutyl butanoate 2-Methylbutyl 2-methylbutanoate Isoamyl isovalerate Ethyl heptanoate Ethyl octanoate Ethyl decanoate
RIa
containing compounds Dimethyl disulfide 2,4,5-Trimethylthiazole 3-(Methylthio)propanal 2-Ethoxythiazole 3-(Methylthio)propanol
Strong, meaty Raw potato
Furans 7 2-Ethylfuran 21 2-n-Butylfuran 35 2-Pentylfuran 67 2-Furaldehyde 71 2-Acetylfuran 81 Furfuryl alcohol
956 1136 1238 1484 1510 1689
MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI,
Std Std Std Std Std Std
2.3 5.0 5.9 9562.0 15,025.2 4500.6
Rubber, pungent Noncharacteristics Green bean like Wood, almond Smoky, tobacco Burnt sugar
Ketones 8 2,3-Butanedione 10 2,3-Pentanedione 38 3-Octanone 43 2-Octanone
985 1052 1265 1295
MS, RI, MS, RI, MS, RI, MS, RI,
Std Std Std Std
0.1 5505.6 21.5 50.3
creamy, caramel Butter scotch Mashroom, harbal Soapy, floral
Sweet, cheese
54
1345 MS, RI, Std
68.0
Over ripe fruit
77
1610 MS, RI, Std
5.5
RI, retention index. MS, mass spectrum; RI, retention index; Std, confirmation by authentic. Cited from our previous investigation (Giri, Osako, Okamoto, & Ohshima, 2010).
6-Methyl-5-hepten 2-one 2-Undecanone
Sweet, fruity Tallow, musty
742
Table 2 Changes of volatile contents (μg/kg of sample) and OAVs (in parenthesis) of miso prepared from squid meat during hypobaric and temperature dependent storage. Peak Volatile compounds no. Aldehydes 1 Acetaldehyde 2 2-Methylpropanal 4 2-Methylbutanal 5 3-Methylbutanal 14 Hexanal 27 Heptanal 33 2-Hexenal (Z) 37 4-Heptenal 44 Octanal 59 Nonanal 70 2,4-Heptadienal (E,Z) 76 2,4-Heptadienal (E,E)
Esters 3 9 13 17 20 23 36
Ethyl acetate 2-Methylpropyl acetate Butyl acetate Isobutyl isobutyrate Isoamyl acetate Ethyl pentanoate Ethyl hexanoate
7.4 (0.3) 6.9 (4.6) 0.3 (0.3) 5.0 (31.7) 9.9 (2.0) 5.6 (1.9) 0.1 (b 0.1) 0.3 (0.1) 0.9 (1.6) 0.2 (0.2) 0.4 (b 0.1) 0.3 (b 0.1)
45 days storage HTa 16.4 (0.7) 9.1 (6.0) 0.9 (0.9) 6.2 (38.7) 9.0 (1.8) 17.6 (6.1) 0.2 (b 0.1) 0.3 (0.1) 1.7 (2.9) 1.1 (1.0) 4.3 (b 0.1) 0.5 (b 0.1)
90 days storage
LTb 14.7 (0.6) 8.2 (5.4) 0.3 (0.3) 5.2 (32.7) 8.4 (1.7) 6.9 (2.4) 0.2 (b 0.1) 0.2 (0.1) 0.9 (1.5) 0.2 (0.2) 2.6 (b 0.1) 0.3 (b 0.1)
LPc 9.5 (0.4) 7.4 (4.9) 0.3 (0.3) 4.9 (30.8) 6.8 (1.4) 4.4 (1.5) 0.1 (b 0.1) 0.2 (0.1) 0.7 (1.3) 0.2 (0.2) 0.4 (b 0.1) 0.3 (b 0.1)
HT 15.9 (0.6) 19.2 (12.8) 1.1 (1.1) 3.9 (24.6) 5.7 (1.1) 15.7 (5.4) 0.3 (b 0.1) 0.4 (0.1) 1.6 (2.7) 0.7 (0.7) 2.4 (b 0.1) 0.5 (b 0.1)
180 days storage
LT 17.8 (0.7) 8.6 (5.7) 0.5 (0.5) 5.0 (31.2) 3.1 (0.6) 11.1 (3.9) 0.3 (b 0.1) 0.3 (0.1) 1.4 (2.4) 0.1 (0.1) 1.9 (b 0.1) 0.2 (b 0.1)
LP
HT
16.6 (0.7) 8.2 (5.4) 0.2 (0.2) 4.4 (27.4) 4.4 (0.9) 3.3 (1.2) 0.1 (b 0.1) 0.2 (b 0.1) 0.7 (1.1) 0.2 (0.2) 0.3 (b 0.1) 0.2 (b 0.1)
23.8 (0.9) 26.1 (17.4) 1.4 (1.4) 5.2 (32.9) 4.0 (0.8) 10.9 (3.8) 0.1 (b 0.1) 0.3 (0.1) 6.3 (10.7) 0.4 (0.4) 9.6 (b 0.1) 0.5 (b 0.1)
184.1 (b 0.1) 256.8 (b 0.1) 294.4 (b 0.1) 329.7 (b 0.1) 246.2 (b 0.1) 313.1 (b 0.1) 247.1 (b 0.1) 151.3 (b 0.1) 51.1 (b 0.1) 113.1 (b 0.1) 318.8 (b 0.1) 159.6 (b 0.1) 300.6 (b 0.1) 321.2 (b 0.1) 370.4 (b 0.1) 146.4 (b 0.1) 1.0 (b 0.1) 3.1 (b 0.1) 4.3 (b 0.1) 3.5 (b 0.1) 3.5 (b 0.1) 7.3 (b 0.1) 4.5 (b 0.1) 1.9 (b 0.1) 2.2 (b 0.1) 4.8 (b 0.1) 2.7 (b 0.1) 5.2 (b 0.1) 5.2 (b 0.1) 3.9 (b 0.1) 8.6 (b 0.1) 5.5 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.4 (b 0.1) 0.2 (b 0.1) 3.3 (b 0.1) 4.7 (b 0.1) 5.1 (b 0.1) 5.9 (b 0.1) 2.7 (b 0.1) 4.5 (b 0.1) 6.7 (b 0.1) 2.7 (b 0.1) 13.1 (b 0.1) 34.8 (0.1) 55.0 (0.1) 41.6 (0.1) 24.8 (0.1) 65.3 (0.1) 29.3 (0.1) 42.6 (0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.5 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.4 (b 0.1) 0.8 (b 0.1) 3.2 (0.2) 0.4 (b 0.1) 0.5 (b 0.1) 3.5 (0.2) 0.6 (b 0.1) 0.5 (b 0.1) 43.4 (10.8) 86.5 (21.5) 104.3 (26.0) 123.3 (30.7) 151.6 (37.8) 98.0 (24.4) 114.5 (28.5) 180.3 (44.9) 2.2 (b 0.1) 1.4 (b 0.1) 0.6 (b 0.1) 2.7 (b 0.1) 0.6 (b 0.1) 0.5 (b 0.1) 2.1 (b 0.1) 0.5 (b 0.1) 0.9 (b 0.1) 1.7 (b 0.1) 1.4 (b 0.1) 1.7 (b 0.1) 3.0 (b 0.1) 3.7 (b 0.1) 2.6 (b 0.1) 2.4 (b 0.1) 0.7 (0.1) 1.4 (0.2) 0.8 (0.1) 0.9 (0.1) 0.7 (0.1) 1.2 (0.2) 1.3 (0.2) 1.1 (0.2) 0.3 (b 0.1) 0.5 (b 0.1) 0.3 (b 0.1) 0.4 (b 0.1) 0.5 (b 0.1) 0.4 (b 0.1) 0.6 (b 0.1) 0.7 (b 0.1) 0.3 (b 0.1) 0.7 (b 0.1) 0.3 (b 0.1) 0.6 (b 0.1) 0.6 (b 0.1) 0.4 (b 0.1) 0.7 (b 0.1) 0.8 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 1.1 (b 0.1) 1.1 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 0.7 (b 0.1) 0.2 (b 0.1) 0.6 (b 0.1) 0.7 (b 0.1) 0.3 (b 0.1) 1.0 (b 0.1) 0.3 (b 0.1) 0.4 (b 0.1) 1.2 (b 0.1) 0.6 (b 0.1) 0.8 (b 0.1) 3.9 (b 0.1) 5.5 (b 0.1) 4.7 (b 0.1) 4.5 (b 0.1) 0.1 0.1 0.1 0.2 0.2 0.1 0.2 0.1 0.2 (b 0.1) 0.4 (0.1) 0.6 (0.1) 0.5 (0.1) 0.6 (0.1) 0.3 (0.1) 0.7 (0.1) 0.4 (0.1) 0.0 (b 0.1) 0.2 (b 0.1) 0.0 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.0 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.4 (b 0.1) 0.3 (b 0.1) 0.4 (b 0.1) 0.4 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.9 (0.6) 2.7 (1.8) 1.1 (0.7) 1.8 (1.2) 3.0 (2.0) 1.0 (0.7) 2.6 (1.7) 4.3 (2.8) 0.9 (0.2) 1.7 (0.3) 1.8 (0.3) 2.0 (0.4) 1.1 (0.2) 1.9 (0.4) 1.8 (0.3) 1.5 (0.3) 10.1 (b 0.1) 15.3 (b 0.1) 10.5 (b 0.1) 12.2 (b 0.1) 8.0 (b 0.1) 14.2 (b 0.1) 17.7 (b 0.1) 4.9 (b 0.1) 4.8 (b 0.1) 5.9 (b 0.1) 3.1 (b 0.1) 4.3 (b 0.1) 5.6 (b 0.1) 3.1 (b 0.1) 4.1 (b 0.1) 3.0 (b 0.1) 0.7 (b 0.1) 0.9 (b 0.1) 0.5 (b 0.1) 0.7 (b 0.1) 0.9 (b 0.1) 0.4 (b 0.1) 0.8 (b 0.1) 1.5 (b 0.1) 0.9 (b 0.1) 8.5 (0.1) 0.8 (b 0.1) 8.3 (0.1) 8.6 (0.1) 1.7 (b 0.1) 10.8 (0.1) 11.0 (0.1) 0.7 (b 0.1) 1.3 (b 0.1) 0.8 (b 0.1) 1.4 (b 0.1) 1.3 (b 0.1) 0.9 (b 0.1) 1.6 (b 0.1) 1.9 (b 0.1)
0.7 (0.1) 0.8 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.4 (0.3) 4.7 (0.8) 0.1 (0.1)
2.1 (0.4) 0.9 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.3 (0.2) 8.7 (1.5) 0.3 (0.1)
1.1 (0.2) 0.9 (b 0.1) 0.1 (b 0.1) 0.0 (b 0.1) 0.2 (0.2) 9.4 (1.6) 0.1 (b 0.1)
2.7 (0.5) 1.0 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.5 (0.3) 8.2 (1.4) 0.2 (0.1)
2.7 (0.5) 0.4 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.3 (0.2) 4.0 (0.7) 0.3 (0.1)
1.1 (0.2) 0.8 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.3 (0.2) 10.0 (1.7) 0.1 (0.1)
4.1 (0.8) 1.1 (b 0.1) 0.1 (b 0.1) 0.3 (b 0.1) 0.6 (0.4) 7.5 (1.3) 0.4 (0.2)
4.4 (0.9) 0.4 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.3 (0.2) 2.9 (0.5) 0.2 (0.1)
270 days storage
LT 19.9 10.3 0.6 5.4 3.9 10.0 0.4 0.2 2.0 0.2 3.1 0.5
LP (0.8) (6.8) (0.6) (34.2) (0.8) (3.5) (b 0.1) (b 0.1) (3.4) (0.2) (b 0.1) (b 0.1)
241.0 (b 0.1) 452.5 (0.1) 3.8 (b 0.1) 4.0 (b 0.1) 1.2 (b 0.1) 5.6 (b 0.1) 136.9 (0.3) 0.4 (b 0.1) 4.9 (0.3) 101.8 (25.4) 1.3 (b 0.1) 4.7 (b 0.1) 1.2 (0.2) 0.7 (b 0.1) 0.5 (b 0.1) 0.6 (b 0.1) 0.2 (b 0.1) 9.2 (b 0.1) 0.1 0.2 (b 0.1) 0.1 (b 0.1) 0.4 (b 0.1) 0.2 (b 0.1) 1.2 (0.8) 1.6 (0.3) 22.5 (b 0.1) 1.5 (b 0.1) 0.3 (b 0.1) 3.0 (b 0.1) 1.5 (b 0.1)
1.1 0.9 0.1 0.4 0.3 10.7 0.2
(0.2) (b 0.1) (b 0.1) (b 0.1) (0.2) (1.8) (0.1)
HT
27.8 7.7 0.3 4.5 2.5 2.4 0.1 0.2 0.6 0.2 0.3 0.2
25.1 (1.0) 8.1 (5.4) 0.3 (0.3) 3.2 (19.9) 2.7 (0.5) 1.7 (0.6) 0.1 (b 0.1) 0.1 (b 0.1) 0.6 (1.0) 0.2 (0.2) 0.4 (b 0.1) 0.2 (b 0.1)
97.9 (b 0.1) 106.9 (b 0.1) 203.9 (b 0.1) 174.4 (b 0.1) 44.7 (b 0.1) 13.9 (b 0.1) 2.6 (b 0.1) 2.6 (b 0.1) 2.9 (b 0.1) 5.9 (b 0.1) 4.4 (b 0.1) 3.6 (b 0.1) 0.4 (b 0.1) 0.2 (b 0.1) 7.5 (b 0.1) 4.4 (b 0.1) 1.2 (b 0.1) 2.4 (b 0.1) 28.8 (0.1) 31.7 (0.1) 46.1 (0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 1.3 (0.1) 57.1 (14.2) 450.6 (112.3) 29.3 (7.3) 1.5 (b 0.1) 0.2 (b 0.1) 1.4 (b 0.1) 2.7 (b 0.1) 3.3 (b 0.1) 1.9 (b 0.1) 1.1 (0.1) 0.8 (0.1) 0.0 (b 0.1) 0.9 (b 0.1) 0.6 (b 0.1) 0.4 (b 0.1) 0.9 (b 0.1) 0.5 (b 0.1) 0.3 (b 0.1) 2.1 (b 0.1) 0.2 (b 0.1) 0.4 (b 0.1) 0.7 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 3.5 (b 0.1) 5.3 (b 0.1) 0.6 (b 0.1) 0.2 0.1 0.1 0.6 (0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.0 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 3.4 (2.2) 9.3 (6.1) 1.4 (0.9) 1.7 (0.3) 1.7 (0.3) 1.2 (0.2) 13.7 (b 0.1) 9.3 (b 0.1) 7.8 (b 0.1) 3.4 (b 0.1) 2.5 (b 0.1) 1.2 (b 0.1) 0.7 (b 0.1) 0.8 (b 0.1) 0.3 (b 0.1) 9.8 (0.1) 8.9 (0.1) 4.7 (b 0.1) 2.5 (0.1) 1.8 (b 0.1) 1.4 (b 0.1)
62.3 (b 0.1) 107.6 (b 0.1) 1.9 (b 0.1) 5.0 (b 0.1) 0.3 (b 0.1) 2.2 (b 0.1) 13.7 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 19.8 (4.9) 0.6 (b 0.1) 2.7 (b 0.1) 0.6 (0.1) 0.9 (b 0.1) 0.8 (b 0.1) 1.8 (b 0.1) 0.7 (b 0.1) 2.3 (b 0.1) 0.2 0.5 (0.1) 0.1 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 3.4 (2.2) 1.5 (0.3) 12.2 (b 0.1) 1.8 (b 0.1) 0.6 (b 0.1) 9.2 (0.1) 2.3 (0.1)
(1.2) (b 0.1) (b 0.1) (b 0.1) (0.3) (1.1) (0.2)
15.4 24.0 1.5 4.7 4.7 2.7 0.1 0.2 7.7 0.3 3.0 0.5
6.5 0.3 0.1 0.2 0.2 0.1 0.2
(0.6) (16.0) (1.4) (29.8) (0.9) (0.9) (b 0.1) (0.1) (13.0) (0.3) (b 0.1) (b 0.1)
LP (0.1) (5.8) (0.7) (22.2) (1.2) (3.0) (b 0.1) (b 0.1) (1.2) (0.2) (b 0.1) (b 0.1)
6.0 1.1 0.1 0.5 0.4 6.2 0.4
(1.1) (5.1) (0.3) (28.1) (0.5) (0.8) (b 0.1) (b 0.1) (1.0) (0.2) (b 0.1) (b 0.1)
LT
(1.3) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.1)
2.9 8.7 0.7 3.5 6.2 8.7 0.2 0.1 0.7 0.2 2.5 0.2
0.7 1.2 0.1 3.3 0.3 7.6 0.1
(0.1) (b 0.1) (b 0.1) (0.1) (0.2) (1.3) (b 0.1)
7.0 (1.4) 1.1 (b 0.1) 0.1 (b 0.1) 0.6 (b 0.1) 0.4 (0.3) 4.9 (0.8) 0.3 (0.1)
A. Giri et al. / Food Research International 44 (2011) 739–747
Alcohols 6 Ethanol 11 1-Propanol 15 3-Methyl-2-butanol 16 2-Methylpropanol 19 3-Pentanol 24 1-Butanol 26 1-Penten 3-ol 29 3-Hexanol 31 2-Methyl-1-butanol 32 3-Methyl-1-butanol 34 2-Hexanol 39 1-Pentanol 46 3-Methyl-1-pentanol 48 2-Ethyl 1-butanol 49 Cyclopentanol 50 2-Heptanol 51 2-Penten-1-ol (E) 52 3-Methyl-3-buten-1-ol 55 1-Hepten-3-ol 56 Hexanol 58 3-Octanol 60 2-Hexen-1-ol (E) 61 2-Hexen-1-ol (Z) 64 1-Octen-3-ol 65 Heptanol 69 2-Ethyl hexanol 72 2-Nonanol 74 Octanol 75 2,3-Butanediol (meso) 79 1-Nonanol
Matured miso
40 42
3-Methylbutyl 2-Methylbutyl 2methylbutanoate Isoamyl isovalerate Ethyl heptanoate Ethyl octanoate Ethyl decanoate
0.9 0.6 1.0 14.2
Ketones 8 2,3-Butanedione 10 2,3-Pentanedione 38 3-Octanone 43 2-Octanone 54 6-Methyl-5-hepten 2-one 77 2-Undecanone
1.7 215.3 1.1 0.2 0.5 1.0
45 53 63 78
Sulfur 12 57 66 84 86
containing compounds Dimethyl disulfide 2,4,5-Trimethylthiazole 3-(Methylthio)-propanal 2-Ethoxythiazole 3-(Methylthio)-propanol
Nitrogen containing compounds 47 2,3-Dimethylpyrazene 62 2,3,5-Trimethylpyrazine 68 Tetramethylpyrazine 91 2-Acetylpyrrole Aromatic compounds 18 Ethyl benzene 22 p-Xylene 25 o-Xylene 28 Cymene 30 Propyl benzene 41 p-Cymene 73 Benzaldehyde 80 Ethyl benzoate 85 4-Ethyl benzaldehyde 87 Ethylphenyl acetate 88 2-Phenylethyl acetate 89 Benzyl alcohol 90 Phenylethyl alcohol 92 Phenol 93 4-Ethylguaiacol 94 4-Ethylphenol Acids 82 2-Methylbutanoic acid 83 3-Methylbutanoic acid a b
HT, atmospheric pressure at 25 °C. LT, atmospheric pressure at 10 °C. LP, hypobaric 10 kPa at 25 °C.
1.9 4.6 4.4 66.4
(0.1) (2.3) (0.2) (13.2)
0.1 (b 0.1) 0.3 (b 0.1) 1.3 2.1 2.0 14.0
(0.1) (1.0) (0.1) (2.8)
0.3 (b 0.1) 0.3 (b 0.1) 1.4 2.9 3.9 61.3
(0.1) (1.5) (0.2) (12.2)
0.4 (b 0.1) 0.2 (b 0.1) 1.4 5.8 1.6 69.3
(0.1) (2.9) (0.1) (13.8)
0.1 (b 0.1) 0.2 (b 0.1) 1.8 2.8 2.9 17.6
(0.1) (1.4) (0.2) (3.5)
0.4 (b 0.1) 0.3 (b 0.1) 2.1 5.2 5.3 80.4
(0.1) (2.6) (0.3) (16.0)
0.3 (b 0.1) 0.2 (b 0.1) 1.3 5.3 1.3 73.8
(0.1) (2.7) (0.1) (14.7)
(29.2) 2.1 (36.4) 1.8 (30.7) 2.5 (42.2) 2.3 (38.5) 3.6 (60.3) 2.7 (45.8) 2.8 (48.1) (b 0.1) 423.7 (0.1) 261.2 (b 0.1) 229.5 (b 0.1) 311.1 (0.1) 406.1 (0.1) 166.1 (b 0.1) 176.9 (b 0.1) (0.1) 1.1 (b 0.1) 0.8 (b 0.1) 0.7 (b 0.1) 1.2 (0.1) 1.3 (0.1) 0.6 (b 0.1) 1.0 (b 0.1) (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) (b 0.1) 2.0 (b 0.1) 0.6 (b 0.1) 0.3 (b 0.1) 2.2 (b 0.1) 1.1 (b 0.1) 0.4 (b 0.1) 1.4 (b 0.1) (0.2) 5.9 (1.1) 0.9 (0.2) 1.0 (0.2) 6.0 (1.1) 0.8 (0.1) 1.1 (0.2) 12.8 (2.3)
0.2 (b 0.1) 0.2 (b 0.1) 2.1 (0.1) 3.2 (1.6) 2.5 (0.1) 19.8 (3.9)
5.6 (95.7) 357.7 (0.1) 1.8 (0.1) 0.1 (b 0.1) 1.6 (b 0.1) 0.9 (0.2)
0.4 (b 0.1) 0.3 (b 0.1)
0.4 (b 0.1) 0.2 (b 0.1)
0.1 (b 0.1) 0.2 (b 0.1)
0.4 (b 0.1) 0.3 (b 0.1)
2.3 (0.1) 7.1 (3.6) 4.9 (0.3) 77.4 (15.4)
1.0 (0.1) 4.7 (2.4) 1.2 (0.1) 71.1 (14.2)
0.5 (b 0.1) 4.9 (2.5) 1.4 (0.1) 34.8 (6.9)
2.2 6.7 4.8 84.3
(0.1) (3.4) (0.2) (16.8)
1.7 (28.0) 2.1 (36.1) 120.6 (b 0.1) 115.2 (b 0.1) 0.5 (b 0.1) 0.7 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.6 (b 0.1) 0.9 (0.2) 15.1 (2.7)
2.9 (48.7) 95.9 (b 0.1) 0.7 (b 0.1) 0.1 (b 0.1) 2.2 (b 0.1) 0.7 (0.1)
1.0 52.3 0.4 0.1 0.3 0.6
(17.2) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1)
0.5 0.2 0.9 0.2 0.3 3.2
(0.2) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
0.8 0.2 1.6 0.4 0.3 9.5
(0.3) (b 0.1) (0.3) (b 0.1) (b 0.1) (b 0.1)
0.7 0.2 1.1 0.2 0.3 3.6
(0.3) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
0.5 0.2 1.0 0.4 0.3 9.3
(0.2) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
0.9 0.3 1.7 1.3 0.4 10.1
(0.4) (0.1) (0.3) (b 0.1) (b 0.1) (b 0.1)
1.9 0.2 1.2 0.5 0.3 7.4
(0.8) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
0.6 0.2 0.9 1.6 0.3 11.9
(0.3) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
1.1 0.3 1.4 2.1 0.3 12.6
(0.5) (0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
3.2 (1.4) 0.2 (b 0.1) 0.9 (0.2) 0.6 (b 0.1) 0.3 (b 0.1) 8.7 (b 0.1)
0.7 (0.3) 0.2 (b 0.1) 1.0 (0.2) 3.1 (b 0.1) 0.3 (b 0.1) 15.2 (b 0.1)
0.9 (0.4) 0.3 (0.1) 1.8 (0.3) 2.9 (b 0.1) 0.4 (b 0.1) 21.6 (b 0.1)
1.7 (0.7) 0.2 (b 0.1) 1.2 (0.2) 0.6 (b 0.1) 0.4 (b 0.1) 8.7 (b 0.1)
0.5 0.2 0.8 3.4 0.2 26.1
(0.2) (b 0.1) (0.1) (b 0.1) (b 0.1) (b 0.1)
2.0 0.2 15.7 0.5 1.4
(1.8) (b 0.1) (34.2) (b 0.1) (b 0.1)
2.4 0.5 27.1 0.9 1.9
(2.3) (b 0.1) (59.1) (b 0.1) (b 0.1)
2.3 0.2 18.3 0.7 2.8
(2.2) (b 0.1) (39.9) (b 0.1) (b 0.1)
0.9 0.2 14.0 0.8 2.7
(0.8) (b 0.1) (30.7) (b 0.1) (b 0.1)
0.9 0.9 42.2 1.0 8.4
(0.8) (b 0.1) (92.1) (b 0.1) (b 0.1)
0.5 0.2 21.2 1.1 7.7
(0.5) (b 0.1) (46.3) (b 0.1) (b 0.1)
0.3 0.2 13.9 0.9 4.7
(0.3) (b 0.1) (30.3) (b 0.1) (b 0.1)
0.5 0.7 65.1 2.8 10.5
(0.5) (b 0.1) (142.2) (b 0.1) (b 0.1)
0.6 (0.6) 0.2 (b 0.1) 83.0 (181.2) 1.2 (b 0.1) 6.3 (b 0.1)
0.3 (0.3) 0.2 (b 0.1) 12.4 (27.1) 1.4 (b 0.1) 6.8 (b 0.1)
0.1 (0.1) 0.5 (b 0.1) 83.0 (181.2) 7.0 (b 0.1) 9.7 (b 0.1)
0.1 (0.1) 0.2 (b 0.1) 98.0 (213.9) 1.6 (b 0.1) 5.6 (b 0.1)
0.1 0.2 10.6 2.5 6.8
(0.1) (b 0.1) (23.2) (b 0.1) (b 0.1)
0.1 0.1 0.1 3.1
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 2.0 0.1 2.5
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 0.1 0.1 3.7
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 0.6 0.1 3.5
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 1.1 0.1 2.8
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 0.1 0.1 3.8
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 0.7 0.1 4.2
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
3.0 0.5 0.1 3.8
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
1.2 (b 0.1) 0.6 (b 0.1) 0.1 (b 0.1) 6.1 (b 0.1)
0.1 (b 0.1) 0.6 (b 0.1) 0.1 (b 0.1) 6.0 (b 0.1)
4.4 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 9.9 (b 0.1)
0.1 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 3.5 (b 0.1)
0.1 0.9 0.1 7.3
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.0 0.2 0.2 0.1 0.2 0.1 4.4 5.0 0.1 1.1 1.1 0.3 67.3 0.4 17.2 0.1
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.2) (b 0.1)
0.0 0.1 0.5 0.1 0.2 0.0 7.5 9.1 0.1 1.6 3.3 0.9 73.8 0.8 26.7 1.4
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.3) (b 0.1)
0.2 0.1 0.7 0.2 0.4 0.0 5.3 2.7 0.1 1.4 1.2 0.3 52.0 0.6 16.6 0.1
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.2) (b 0.1)
0.0 0.1 0.2 0.0 0.0 0.0 4.0 6.3 0.1 1.5 3.3 0.8 91.0 0.5 22.2 1.5
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (0.2) (b 0.1)
0.3 0.1 0.4 0.1 0.1 0.0 7.6 6.0 0.1 3.8 9.0 1.4 99.6 1.3 37.6 1.9
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (0.4) (b 0.1)
0.2 0.1 1.0 0.2 0.1 0.0 6.4 1.8 0.1 1.4 1.5 0.3 47.7 0.7 18.6 1.1
(b 0.1) 0.0 (b 0.1) (b 0.1) 0.1 (b 0.1) (b 0.1) 0.1 (b 0.1) (b 0.1) 0.0 (b 0.1) (b 0.1) 0.0 (b 0.1) (b 0.1) 0.0 (b 0.1) (b 0.1) 2.8 (b 0.1) (b 0.1) 8.9 (0.2) (b 0.1) 0.1 (b 0.1) (b 0.1) 1.9 (b 0.1) (b 0.1) 9.6 (b 0.1) (b 0.1) 1.6 (b 0.1) (0.1) 116.2 (0.2) (b 0.1) 1.1 (b 0.1) (0.2) 24.7 (0.3) (b 0.1) 2.1 (b 0.1)
0.2 0.2 0.6 0.1 0.1 0.0 12.4 12.5 0.1 7.2 11.3 1.5 95.7 1.9 51.8 2.4
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (0.6) (b 0.1)
0.8 (b 0.1) 0.1 (b 0.1) 2.2 (b 0.1) 0.2 (b 0.1) 0.4 (b 0.1) 0.3 (b 0.1) 7.2 (b 0.1) 2.7 (b 0.1) 0.1 (b 0.1) 1.6 (b 0.1) 1.5 (b 0.1) 0.8 (b 0.1) 39.4 (0.1) 1.0 (b 0.1) 19.8 (0.2) 1.8 (b 0.1)
0.0 (b 0.1) 1.7 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.5 (b 0.1) 0.1 (b 0.1) 0.3 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.0 (b 0.1) 0.1 (b 0.1) 2.0 (b 0.1) 15.2 (b 0.1) 8.1 (0.1) 18.5 (0.3) 0.1 (b 0.1) 0.2 (b 0.1) 3.2 (b 0.1) 9.9 (0.1) 12.8 (0.1) 11.7 (b 0.1) 2.2 (b 0.1) 1.5 (b 0.1) 121.4 (0.2) 115.2 (0.2) 1.4 (b 0.1) 1.9 (b 0.1) 30.2 (0.3) 84.9 (1.0) 2.6 (b 0.1) 2.8 (b 0.1)
0.3 (b 0.1) 0.2 (b 0.1) 1.4 (b 0.1) 0.4 (0.1) 0.7 (b 0.1) 0.7 (b 0.1) 8.9 (11.1) 1.7 (b 0.1) 0.1 (b 0.1) 1.6 (b 0.1) 1.2 (b 0.1) 0.3 (b 0.1) 65.3 (0.1) 1.3 (b 0.1) 18.6 (0.2) 1.9 (b 0.1)
0.0 0.1 0.2 0.1 0.1 0.1 2.0 7.7 0.1 4.6 12.9 2.3 133.3 1.6 44.2 3.2
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (2.8) (0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.2) (b 0.1) (0.5) (b 0.1)
3.5 (5.5) 0.5 (b 0.1)
0.3 (0.5) 0.2 (b 0.1)
0.8 (1.2) 0.0 (b 0.1)
0.9 (1.5) 0.3 (b 0.1)
0.1 (0.1) 0.0 (b 0.1)
0.1 (0.2) 0.1 (b 0.1)
1.4 (2.2) 0.4 (b 0.1)
0.1 (0.2) 0.1 (b 0.1)
0.3 (0.4) 0.2 (b 0.1)
0.6 (0.9) 0.3 (b 0.1)
5.4 (8.6) 0.6 (b 0.1)
0.8 (1.2) 0.2 (b 0.1)
0.5 (0.8) 0.4 (b 0.1)
743
c
(b 0.1) (0.3) (0.1) (2.3)
0.4 (b 0.1) 0.3 (b 0.1)
A. Giri et al. / Food Research International 44 (2011) 739–747
Furans 7 2-Ethylfuran 21 2-n-Butylfuran 35 2-Pentylfuran 67 2-Furaldehyde 71 2-Acetylfuran 81 Furfuryl alcohol
0.2 (b 0.1) 0.2 (b 0.1)
744
A. Giri et al. / Food Research International 44 (2011) 739–747
DNS and amylase activity were monitored spectrophotometrically at 540 nm after cooling in ice for 5 min. 2.10.3. Lipase activity The reaction was stopped with a SDS-fast blue BB salt (1.4 and 0.2%, respectively) solution. The diazo-1-naphthol hydrolyzed product was monitored at 600 nm after incubating at 35 °C for 5 min. The production of soluble protein, reducing sugars, and 1-naphthol was used as the respective indices of the enzyme activities under different experimental conditions. 2.11. Sensory evaluation Flavor profile characterization of squid miso was performed in the Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Japan. The panel has previous experiences of evaluating sensory perception of several Japanese fermented food products. Training of the panel for characterizing newly developed squid miso samples was conducted over two, threehour sessions in isolated booths at room temperature and under mild light (British Standard Institution Assessors for Sensory Analysis, 1993). Based on the consistency during training period 16 sensory panelists were selected. The panel was well introduced about flavor profiles of several traditional miso products. The 90 days fermented matured squid miso and 270 days stored products under different conditions kept at −80 °C were thawed overnight at 5 °C and the samples were stabilized at serving temperature of 40 °C for 30 min just before evaluation. Undiluted coded miso samples of 5 g were introduced to the panelists in random order in porcelain plates of similar size. The attributes that best described the fermented miso aroma characteristics were selected by the panelists. From these attributes, five consensual odor descriptors including “fishy,” “nutty,” “cheesy,” “fruity” and “meaty” were established. The odor intensity of each attribute was rated on the following scale: −2, very weak; −1, weak; 0, moderate; + 1, strong; + 2, very strong. This experiment was conducted once and the data was analyzed based on the observations of 16 sensory panelists. 2.12. Statistical analysis The results for the volatile compounds were reported as mean values. Analyses were performed in triplicate. Enzyme activity data sets were evaluated by analysis of variance (ANOVA). A statistically significant difference was identified at the 95% confidence level. Posthoc mean comparisons were made on the basis of the P values (α = 0.05) by using Duncan's multiple range test. 3. Results and discussion 3.1. Changes of volatile compounds in squid miso during storage A total of 94 headspace volatile compounds isolated and detected by a combination of a Tenax TA trap and GC-FID were identified and quantified as shown in Tables 1 and 2, respectively. The volatile classes included aldehydes, alcohols, esters, ketones, furans, sulfurs, nitrogenous compounds, aromatic compounds, and volatile acids. The OAVs, obtained by dividing the concentration of each compound by its odor threshold in water, were used to assess the relative importance of individual odorants to the aroma profile of the squid miso products. Changes in volatile classes are presented in Fig. 1. The volatile aldehydes acetaldehyde, 2-methylpropanal, 3methylbutanal, hexanal, heptanal, and octanal were prominent compounds detected throughout the storage periods. Considering the higher OAVs, 2-methylpropanal (nutty, malty), 3-methylbutanal (almond, nutty), hexanal (fishy, grassy), heptanal (dry fish), and octanal (fatty, pungent) might significantly contribute to the aroma of the miso
prepared from squid meat. Among the aldehydes, 2-methylpropanal and 3-methylbutanal generally originate from the Strecker degradation of amino acids (Belitz & Grosch, 1987; Dwivedi, 1975) and were reported to produce in several meat fermented products including sausage (Olivares, Navarro, & Flores, 2009). However, hexanal, heptanal, and octanal are generated as a result of lipid oxidation during fermentation and storage. A rapid increase in aldehyde formation was observed during HT-Atm storage. Most of the Strecker-degraded aldehydes with nutty nuance increased rapidly. Lipid oxidation products increased in the early days of storage and tended to decrease after 90 days of storage. In contrast, both the LT-Atm and HT-Hypobaric storage retarded aldehyde production. This is probably due to the effect of low storage temperature as well as the hypobaric condition, in which the oxygen availability is limited. Comparative studies of LT-Atm and HT-Hypobaric storage conditions revealed that hypobaric storage could potentially prevent aldehyde production, although a higher storage temperature was maintained. The contents of alcohols including ethanol, 1-propanol, 1-penten3-ol, 3-methyl-1-butanol, and 2-ethyl hexanol increased until 90 days of storage and then decreased gradually. Considering the OAVs, most of the volatile alcohols had less impact on squid miso aroma. However, 3-methyl-1-butanol (balsamic), 1-octen-3-ol (mushroom, fishy), and heptanol (fresh, nutty), with lower threshold values, might have contributed to the aroma of the squid miso. Among these, the formation of 3-methyl-1-butanol was prevented by both lowtemperature and low-pressure conditions. The content of esters gradually increased during the storage period irrespective of storage conditions. However, ester production was relatively higher during HT-Hypobaric storage. Alcohol acyltransferase is mainly involved in the formation of volatile esters, transferring the acetyl moiety from acetyl CoA formed via the β-oxidation of fatty acids to an alcohol substrate (Sanz, Olias, & Perez, 1997). Berna et al. (2007) also reported that high partial pressure of oxygen (e.g., 100, 80, and 60 kPa) without CO2 suppressed the biosynthesis of ethyl acetate in strawberries, suggesting a role of hypobaric storage on volatile ester production. Considering the threshold values, ethyl acetate, isoamyl acetate, ethyl pentanoate, and long-chain fatty acid ethyl esters appeared to influence the sweet fruity aroma of the fish miso products. During storage, ketones were more stabilized under the hypobaric condition than under low temperature storage. During HT-Atm and LT-Atm storage, ketone formation was promoted, although it later showed a drastic reduction. Ketones are mainly produced by of lipid auto oxidation and/or amino acid degradation by the Strecker reaction (Thomas, Dimick, & McNeil, 1971). 2,3-Pentanedione was distinct among ketones in the fish miso. Considering the OAVs, however, 2,3-butanedione contributed a creamy or cheesy aroma to the squid miso. The production of furans and their derivatives appeared to be controlled during LT-Atm storage. In contrast, during both HT-Atm and HT-Hypobaric storage, the analogues of furan increased gradually in concentration. Interestingly, during HT-Hypobaric storage, furan analogues such as 2-furaldehydes and furfuryl alcohols increased rapidly in concentration rather than simple furans. This is probably due to the occurrence of dehydration, which takes place at much higher rates in the hypobaric condition (Fig. 2). Furans have been found in dehydrated or fermented condensates of carbohydrates or are formed by the Amadori rearrangement pathways (Whistler & Daniel, 1985). The results for sulfur-containing compounds clearly revealed that the HT-Hypobaric storage condition used in the present study could suppress the formation of certain volatile compounds during storage. Dimethyl disulfide (cooked cabbage) and 3-(methylthio)propanal (methional) (baked potato, meaty) contributed significant aroma to the squid miso. The amount of methional gradually increased during HT-Atm and LT-Atm storage. The contents of dimethyl trisulfide
Concentration (ug/kg) Concentration (ug/kg) Concentration (ug/kg)
A. Giri et al. / Food Research International 44 (2011) 739–747
HT-Atm 100
1100
Aldehydes
LT-Atm 1100
Alcohols
50
550
550
0
0
0
500
40
Ketones
110
Furans
250
20
55
0
0
0
16
300
Nitrogen containing compounds
0
0
90
180
270
Storage period (day)
0
Acids
4
150
8
HT-Hypobaric Esters
Sulfur containing compounds
8
Aromatic compounds
745
0
90
180
270
Storage period (day)
0
0
90
180
270
Storage period (day)
Fig. 1. Changes of volatile classes during the storage period of fish miso prepared from common squid meat under different storage conditions.
tended to decrease throughout the storage period. These sulfur compounds have previously been reported in fermented bean and fish paste products (Landaud, Helinck, & Bonnarme, 2008) and can be generated either from raw materials or during the fermentation process from free, peptidic, and proteinic sulfur amino acids, as well as glutathione pools in the fish tissue (Herbert & Shewan, 1976). Nitrogen-containing compounds and aromatic compounds present in squid miso have less impact on the aroma of the end product in terms of the relative proportion and OAVs. They are generally formed through the Maillard reaction (Fox & Wallace, 1997) during fermentation and catabolism of aromatic amino acids, respectively (Marilley & Casey, 2004). 2-Methylbutanoic acid and 3-methylbutanoic acid in squid miso rapidly increased during HT-Atm storage. However, volatile acid
production was controlled by both LT-Atm and HT-Hypobaric storage. Among the volatile acids, 2-methylbutanoic acid, due to its lower threshold value, might have contributed a cheesy aroma to the fish miso. Organoleptic perception of the matured squid miso and the stored products under different storage conditions evaluated by panels were presented in Fig. 3. The panel consensually described the products with characteristic cheesy, nutty, meaty, fruity and fishy aroma. The panel expressed the acceptability to the matured miso product prepared from the squid meat considering the similarities to the traditional miso products with enhanced cheesy and sweet aroma. As expected, room temperature storage (HT-Atm) as well as low temperature storage (LT-Atm) at atmospheric pressure, the organoleptic perception has been changed particularly for “nutty,” “fishy”
O CH2OH Furfuryl alcohol H2
CHO
Carbohydrate
Hydrolysis
(CHOH)3 CH2OH
Dehydration (-3H2O)
O CHO
Aldol condensation Furfural
Pentose sugar Oxide catalyst
O
Furan Fig. 2. Hypothetical pathway of furan and related compounds formation during storage of fish miso prepared from common squid meat under different storage conditions.
746
A. Giri et al. / Food Research International 44 (2011) 739–747
2 1 0
Fishy
Fruity
-1
Protease activity (eqv. tyrosine micromol/g)
40
Nutty
HT-Atm HT-Hypobaric HT-Atm-Hypoxic LT-Atm LT-Hypobaric
30
20 a,b a
10
0
a
a
0
a,b
a,b
a
a a
d
d
c b,c b
b a,b a,b a a
a
a
a
20
b
40
b
a,b a
a,b
a
a
a,b a a
60
Incubation period (hours)
Cheesy
Before storage LT-Atm (after storage)
HT-Atm (after storage) HT-Hypobaric (after storage)
Fig. 3. Organoleptic scores for matured fermented squid miso and 270 days stored products under different conditions.
and “meaty” aroma attributes. This was probably due to the development of volatile aldehydes, ketones, sulfur and nitrogencontaining compounds. In contrast, the results revealed no significant difference under the HT-Hypobaric condition even after 270 days of storage. The findings of the present study clearly indicated that the effect of hypobaric storage even at room temperature can significantly maintain the sincineration in order to preserve the aroma attributes. 3.2. In vitro evaluation of different storage conditions on the enzyme activities Freshly prepared koji was used as a source of crude enzymes for the analysis of in vitro enzyme assay. Changes in enzyme activity during the fermentation period are shown in Fig. 4. The results clearly indicated that a significant amount of enzymes, including proteases, lipases, and amylases, were produced after an incubation period of 48 h under the present fermentation conditions. The results of the in vitro enzyme assays clearly indicated that casein was hydrolyzed gradually after 20 h by the proteases in koji when the temperature was maintained at 25 °C (Fig. 5). The hydrolysis of protein appeared to slow down under both hypobaric and hypoxic conditions after 40 h of incubation, although the protease enzyme activity still maintained an increasing pattern at atmospheric pressure. From these findings, it can be concluded that the application of hypobaric storage can significantly reduce protease activity even at low temperature. This is probably due to the lower concentration of residual oxygen in the system rather than hypobaric stress, as the atmospheric hypoxic storage condition produced a similar pattern of protein hydrolysis. In addition, no significant changes occurred
Enzyme activity (U/g)
500 Protease Amylase Lipase
400 300
## ##
200
++
100
**
#+
0
+++ ##
+++
**
**
* 0
1
2
3
Fig. 5. In vitro enzyme activity of protease extracted from koji at different storage conditions. Comparisons were among the different treatments at the certain incubation time. Different letters indicate statistical differences (p b 0.05).
between atmospheric and hypobaric conditions in terms of protease activity at the lower storage temperature of 10 °C. This result suggests that in the present storage condition of 10 °C, the effect of the hypobaric condition might be suppressed by the effect of low storage temperature on protease enzyme activity. On the other hand, lipase activity on 1-naphthyl acetate increased during initial incubation period of 6 h and liberated 1-napthol (Fig. 6). The release of 1-napthol increased significantly during atmospheric storage at 25 °C for 12 h of incubation and then rapidly decreased. Additionally, the amount of liberated 1-napthol was significantly lower during hypobaric and hypoxic storage at 25 °C. No significant difference in lipase activity was observed between atmospheric and hypobaric conditions, although 1-napthol was liberated at a lower storage temperature of 10 °C. The amylase activity of koji on starch showed a similar tendency to that of protease in different storage conditions (Fig. 7). A gradual increasing pattern of releasing reduced sugars was observed at atmospheric storage until 48 h of incubation at 25 °C. Hypobaric and hypoxic storage at 25 °C significantly suppressed amylase activity. No significant difference in amylase activity was observed between hypobaric and hypoxic storage. Sozzi, Trinchero, and Fraschina (1999) also reported that low oxygen storage of fruits retarded the activity of carbohydrate cleaving/hydrolyzing enzymes. However, lowtemperature storage significantly suppressed amylase activity relative to the other high-temperature storage conditions. Thus, in vitro enzyme assays at different storage conditions clearly indicated that HT-Hypobaric storage has potential utility in suppressing the activities of several enzymes, including protease, lipase, and amylase. This suppression of enzyme activities was probably due to the low concentration of residual oxygen rather than the hypobaric
Lipase activity (eqv. 1-naphthol micromol/g)
Meaty
4
3
HT-Atm HT-Hypobaric HT-Atm-Hypoxic LT-Atm LT-Hypobaric
d d c,d
2
c
b,c
c b
b,c
1 a,b
a,b a,b
a,b
a,b
b
b a,b
a
0
0
a
a
20
40
60
Incubation period (hours)
Koji fermentation period (day) Fig. 4. Development of protease, amylase and lipase enzyme activity during koji fermentation period. Different symbols indicate statistical differences (p b 0.05).
Fig. 6. In vitro enzyme activity of lipase extracted from koji at different storage conditions. Comparisons were among the different treatments at the certain incubation time. Different letters indicate statistical differences (p b 0.05).
A. Giri et al. / Food Research International 44 (2011) 739–747
Amylase activity (eqv. glucose micromol/g)
400
HT-Atm HT-Hypobaric HT-Atm-Hypoxic LT-Atm LT-Hypobaric
300
References
e
e
d,e
d,e d,e
d
200
c,d
c,d
c,d
c
c
c b,c
b,c
100
b
b b
a
0
0
b
b
b
b,c b b
b
a
20
747
40
60
Incubation period (hours) Fig. 7. In vitro enzyme activity of amylase extracted from koji at different storage conditions. Comparisons were among the different treatments at the certain incubation time. Different letters indicate statistical differences (p b 0.05).
stress. While considering low-temperature storage, it was not beneficial to adopt a hypobaric technique, as the low storage temperature played a major role in suppressing enzyme activity. The formation of several volatiles in miso-type products are greatly influenced by enzyme activity on several substrates, including amino acids, sugars, and lipids. Therefore, it can be assumed that hypobaric storage of mature squid miso at room temperature can prolong the shelf-life to maintain aroma attributes. 4. Conclusions 2-Methyl propanal, 3-methyl butanal, 3-methyl-1-butanol, n-ethyl decanoate, 2,3-butanedione, dimethyl disulfide, methional, and 2methyl butanoic acid were identified as key aroma compounds in squid miso on the basis of the OAVs. Low-temperature and lowpressure storage retarded volatile formation and extended the valuable shelf life. Hypobaric storage showed a considerable reduction in the amount of oxidation products, particularly aldehydes and ketones. The amount of sulfur-containing compounds and acids were also significantly lower. Ester production was higher in hypobaric conditions. Production of furans and their analogues was controlled under hypobaric storage. This study demonstrated that hypobaric storage could be considered as an effective preservation means of fish miso to prolong shelf-life in order to maintain aroma attributes even at room temperature.
Belitz, H. D., & Grosch, W. (1987). Food chemistry (1st ed). Heidelberg: Springer Verlag. Berna, A. Z., Geysen, S., Li, S., Verlinden, B. E., Larnmertyn, J., & Nicolai, B. A. (2007). Headspace fingerprint mass spectrometry to characterize strawberry aroma at super-atmospheric oxygen conditions. Postharvest Biology and Technology, 46, 230−236. British Standard Institution Assessors for Sensory Analysis (1993). Guide to selection, training and monitoring of selected assessors. B817667. London, United Kingdom: British Standard Institute. Burg, S. P. (1967). Method for storing fruit. U.S. Pat. 3, 333, 967. Dwivedi, B. K. (1975). Meat flavor. CRC Critical Reviews in Food Technology, 5, 487−535. Fox, P. F., & Wallace, J. M. (1997). Formation of flavour compounds. Advances in Applied Microbiology, 45, 17−85. Giri, A., Osako, K., & Ohshima, T. (2009a). Effect of raw materials on the extractive components and taste aspects of fermented fish paste — Sakana miso. Fisheries Science, 75, 785−796. Giri, A., Osako, K., & Ohshima, T. (2009b). Extractive components and taste aspects of fermented fish pastes and bean pastes prepared using different koji molds as starters. Fisheries Science, 75, 481−489. Giri, A., Osako, K., & Ohshima, T. (2010). Identification and characterization of headspace volatiles of fish miso, a Japanese fish meat based fermented paste, with special emphasis on effect of fish species and meat washing. Food Chemistry, 120, 621−631. Giri, A., Osako, K., Okamoto, A., & Ohshima, T. (2010). Olfactometric characterization of aroma active compounds in fermented fish paste in comparison with fish sauce, fermented soy paste and sauce products. Food Research International, 43, 1027−1040. Herbert, R. A., & Shewan, J. M. (1976). Roles played by bacterial and autolytic enzymes in the production of volatile sulphides in spoiling North Sea cod (Gadus morhua). Journal of the Science of Food and Agriculture, 27, 89−94. Landaud, S., Helinck, S., & Bonnarme, P. (2008). Formation of volatile sulfur compounds and metabolism of methionine and other sulfur compounds in fermented food. Applied Microbiology and Biotechnology, 77, 1191−1205. Marilley, L., & Casey, M. G. (2004). Flavours of cheese products: Metabolic pathways, analytical tools and identification of producing strains. International Journal of Food Microbiology, 90, 139−159. Olivares, A., Navarro, J. L., & Flores, M. (2009). Distribution of volatile compounds in lean and subcutaneous fat tissues during processing of dry fermented sausages. Food Research International, 42, 1303−1308. Pesis, E. (1994). Enhancement of fruit aroma and quality by acetaldehyde or anaerobic treatments before storage. Ada Horticulturae, 368, 365−373. Pesis, E., & Avissar, I. (1989). The post-harvest quality of orange fruits as affected by prestorage treatments with acetaldehyde vapour or anaerobic conditions. Journal of Horticultural Science, 64, 107−113. Sanz, C., Olias, J. M., & Perez, A. G. (1997). Aroma biochemistry of fruits and vegetables. In F. A. Tomas-Barberan, & R. J. Robins (Eds.), Phytochemistry of fruit and vegetables (pp. 125−155). Oxford, UK: Clarendon Press. Sozzi, G. O., Trinchero, G. D., & Fraschina, A. A. (1999). Controlled-atmosphere storage of tomato fruit: Low oxygen or elevated carbon dioxide levels alter galactosidase activity and inhibit exogenous ethylene action. Journal of the Science of Food and Agriculture, 79, 1065−1070. Thomas, C. P., Dimick, D. S., & McNeil, J. H. (1971). Sources of flavor in poultry skin. Food Technology, 25, 109−115. Whistler, R. L., & Daniel, J. R. (1985). Carbohydrates. In O. Fennema (Ed.), Food chemistry (pp. 69−137). New York, NY: Marcel Dekker Inc.
Contents lists available at ScienceDirect
Food Research International j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / f o o d r e s
Effects of hypobaric and temperature-dependent storage on headspace aroma-active volatiles in common squid miso Anupam Giri, Kazufumi Osako, Toshiaki Ohshima ⁎ Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo 108-8477, Japan
a r t i c l e
i n f o
Article history: Received 10 November 2010 Accepted 5 January 2011 Keywords: Aroma active compounds Squid miso Hypobaric storage
a b s t r a c t The purpose of this study was to elucidate the effects of storage at hypobaric (10 kPa) atmosphere at room temperature (25 °C) and at a low temperature of 10 °C at atmospheric pressure on the headspace volatiles of miso prepared from common squid meat during 270 days of storage. Based on the odor active values of the volatiles detected, 2-methylpropanal, 3-methylbutanal, 3-methyl-1-butanol, n-ethyl decanoate, 2,3-butanedione, dimethyl disulfide, methional, and 2-methyl butanoic acid were identified as key aroma compounds in squid miso. Low-temperature storage appeared to retard volatile compound formation and extent the shelf life. Hypobaric storage induced a significant reduction in lipid oxidation products, particularly aldehydes and ketones. The contents of sulfur-containing compounds and acids were significantly low; however, esters had relatively higher levels in hypobaric conditions. Production of furans and their derivatives were also found to be controlled by hypobaric storage. Therefore, hypobaric storage can be considered as an effective means of preserving squid miso and related fish paste products to prolong shelf-life in order to maintain aroma attributes. © 2011 Elsevier Ltd. All rights reserved.
1. Introduction The fermented fish meat product fish miso is a promising paste product, for which koji (rice malt) is used as a starter (Giri, Osako, & Ohshima, 2009a). Several investigations of its taste components, nutritional status, and aroma profile have been conducted for the finished product and also during fermentation (Giri, Osako, & Ohshima, 2009b; Giri, Osako, & Ohshima, 2010; Giri et al., 2009a). However, its storage stabilities in terms of volatile compound formation have not been studied previously. Fish miso is considered a live product because of its active enzymes that mostly originate from koji inoculated with Aspergillus oryzae and from fish meat. The volatile profile of fish miso thus appears to be greatly affected by its storage conditions. Therefore, there is necessity to develop an effective means of preserving fish miso to prolong shelf-life to maintain the aroma attributes that are qualitatively and quantitatively appreciated by consumers. Hypobaric storage, a patented method developed by Burg (1967), is an emerging storage technique to extend the useful life of fresh fruits, vegetables, cut flowers, cuttings, potted plants, meat, poultry, fish, shrimp, and other metabolically active matter by lowering atmosphere pressure in a closed chamber. This can quickly remove heat, reduce the oxygen level, and expel harmful gas. It has been reported that fruits exposed to brief periods of low pressure as well as hypoxic storage have reduced postharvest decay (Pesis & Avissar, 1989) and improved fruit
⁎ Corresponding author. Tel.: + 81 3 5463 0613. E-mail address: [email protected] (T. Ohshima). 0963-9969/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodres.2011.01.025
quality (Pesis, 1994) compared to untreated fruit. Sensory analysis indicated that fruit treated with hypoxia had enhanced aroma/flavor. This improvement in flavor was undoubtedly due to increased concentrations of aroma/flavor volatiles induced by exposure to hypoxia (Pesis, 1994). However, no research has been reported on the hypobaric storage of fermented fish paste-like products. Thus, the present study was conducted to evaluate the effect of hypobaric pressure (HT-Hypobaric), atmospheric room temperature (HT), and low temperature (LT) on the headspace volatiles of matured fish miso prepared from common squid meat during storage. In vitro analysis of the substrate specificities of several koji enzymes under different storage conditions was also performed for better understanding. 2. Materials and methods 2.1. Materials Common squid (Todarodes pacificus) with an average body weight of 311 ± 18 g and average mantle length of 24.7 ± 0.5 cm were caught by trawl nets and set nets off the shores of Nagasaki Prefecture. The squid were stored at −50 °C for a month until use for the production of fish miso. 2.2. Chemicals All of the volatile standards used for identification and other analytical purposes were of GC-analytical grade and were purchased from Tokyo Chemical Industry (Tokyo, Japan).
740
A. Giri et al. / Food Research International 44 (2011) 739–747
2.3. Preparation of koji Dried and polished koshihikari rice (Oryza sativa, produced in Niigata Prefecture, Japan) was soaked in fresh water for 12 h at room temperature and was steamed at 90 °C for 1 h. After cooling at room temperature to 35 °C, the rice was inoculated with 0.5% (w/w) koji mold (M1 mold, pure strain of A. oryzae; Nihon Jozo Kogyo, Tokyo, Japan) and incubated at 35 °C for 48 h, and the obtained malt-rice was used as koji. 2.4. Preparation of fermented fish and bean pastes Squid were skinned, and mantle meat was used for paste preparation. After grinding separately with a model M-22 grinder (Nantsune Tekko, Osaka, Japan), the ground meat was put into an aluminum-coated heatstable polyvinylchloride pouch (210 × 150+ 45 mm; Sansyo Co. Ltd., Tokyo, Japan), vacuum-sealed, and then steam-heated at 90 °C for 1 h. Portions were then filter pressed at 2 MPa to achieve moisture contents between 50 and 55%, using a model KS-1 filter press (Komagata Kikai Seisakusho, Tokyo, Japan). The obtained dehydrated meat was used as unwashed meat. Other portions were washed by five volumes of fresh water three times before pressing to obtain washed meat. Squid meat, koji, and salt were mixed with a grinder at the ratio of 5:5:1 by wet weight. About 3 kg of squid paste was packed into a 5-L opaque plastic container (Sansyo Co. Ltd., Tokyo, Japan) tightly sealed with a cap and fermented at a temperature between 25 and 30 °C for 90 days. The contents of each container were mixed thoroughly once a month. The prepared material was called matured squid miso. 2.5. Storage conditions Ninety days fermented matured squid miso was further stored at three different storage conditions. Storage was at atmospheric room temperature (HT-Atm, 25 °C) or atmospheric low temperature (LT-Atm, 10 °C). Hypobaric storage (HT-Hypobaric) was in a container (30 × 30 × 15 cm3) equipped to maintain low pressure (10 kPa) at 25 °C. Samples were stored for a period of 270 days, and small samples were removed for further analysis at 0, 45, 90, 180, and 270 days. Day 0 was counted at the end of the initial 90 days of fermentation. 2.6. Isolation of volatiles using a Tenax TA trap and gas chromatographic analysis Samples (3 g) with an internal standard were placed in 500-mL dual-necked round bottom flasks that were placed over a hot water bath maintained at 75 °C. Nitrogen gas of high purity (99.999%) was passed through the smaller neck of the flask at a flow rate of 100 mL/min, and headspace volatiles emanating from the sample were trapped for 30 min in a glass-fritted absorption trap (4 mm I.D., 6 mm O.D., and 4.5 in. length; Supelco, Belleonte, PA, USA) filled with 175 mg of 60/88 mesh Tenax TA (Supelco) fitted to a bigger neck by a connector. Dry nitrogen purge was performed for 10 min at a flow rate of 50 mL/min in a direction opposite to the isolation to remove residual moisture. The Tenax TA trap was preconditioned at 300 °C for 30 min with nitrogen gas at 50 mL/min by a Model 10 tube conditioner (Dynatherm Analytical Instruments INC., Kelton, PA, USA) before each sampling of the volatile compounds. The dry-purged tube with trapped volatiles was placed in a Model ACEM 900-FF/EPC automated thermal desorption system (CDS Analytical INC., PA, USA). Volatiles trapped in the dry-purged Tenax TA tube were desorbed for 3 min at a temperature of 300 °C and were introduced into a capillary column in a narrow-band plug through a short path transfer line (0.5 m inert capillary column maintained at 250 °C). Analysis of volatiles was performed on a Shimadzu model 14A gas chromatograph (Kyoto, Japan) equipped with a Suplecowax™
10 fused silica capillary column (0.32 mm I.D. × 60 m, 0.25 μm film thickness, Supelco). High purity (99.999%) helium was used as a carrier gas at a flow rate of 1.5 mL/min. The column temperature was maintained at 40 °C for 3 min and subsequently programmed to 200 °C at a rate of 3 °C/min. Injector and detector temperatures were set at 250 °C. 2.7. Conditions of gas chromatography–mass spectrometry Analyses of the mass spectrum of volatile compounds separated by a Suplecowax™ 10 fused silica capillary polar column (0.25 mm I.D. × 60 m, 0.25 μm film thickness; Supelco) were performed on a Hewlett Packard 5890 Series II gas chromatograph equipped with a Tekmar 7000 headspace autosampler (Cincinnati, OH, USA) and an ion source from Automass (JEOL, Japan). The ionization energy, scan range, and scan rate applied in the analysis were 70 eV, 40–350 m/z, and 500 m/s, respectively. The column temperature was initially maintained at 40 °C for 3 min and subsequently increased to 200 °C at a rate of 3 °C/min. 2.8. Identification and quantification of volatile compounds The volatiles were identified on the basis of comparisons of their mass spectra and relative abundances with Wiley spectral libraries (ver. 5). The identity of each compound was further confirmed by comparing its mass spectra, linear retention index (LRI), and retention time with that obtained for an authentic standard. Kovats retention indices (RIs) were determined for both SPME-GC-FID and GC-MS by using a series of n-hydrocarbons (C5–C24) and comparing them with those reported previously (Giri et al., 2010). Quantification of the volatiles was conducted using standard curves obtained from each compound from at least five different concentrations in methanol. The levels of the volatile compounds were normalized by 2,4,6-trimethyl pyridine equivalents by assuming all of the response factors were one. Ten microliters of 2,4,6-trimethyl pyridine of 1 mg/mL was introduced into the 3-g sample just before the volatile isolation process. 2.9. Calculation of odor activity values The odor activity values (OAVs) were determined by dividing the concentration of the odorant in the samples by the mean values of its estimated orthonasal threshold. The threshold values as well as odor descriptions estimated in our previous work were used in the present study (Giri et al., 2010). 2.10. In vitro enzyme assays under different storage conditions Assays for three different enzymes, protease, α-amylase, and lipase, were investigated under different storage conditions identical to miso storage. For these assays, however, two additional storage conditions were adopted for further investigation including LT-Atm (10 °C at atmospheric pressure) and LT-Hypobaric (25 °C at 10 kPa). Crude enzymes from the freshly prepared A. oryzae-fermented rice malt koji for 48 h were extracted with phosphate-buffered saline (100 mM, pH 7.0) at 1:10 w/v ratio. A crude enzyme fraction extracted from koji was appropriately added to several soluble substrates. Sampling was performed at an interval of 6 h during the 60-h storage period. For protease, amylase, and lipase assays, 1% casein, 2.0% (w/v) soluble starch in 0.05 M citric acid buffer (pH 4.8), and 1 × 10−3 M 1-naphthyl acetate were used as substrates, respectively. After sampling at different fermentation periods, activity was measured as described below. 2.10.1. Protease activity After sampling, the reaction was arrested by adding 1 mL of 10% TCA. After centrifuging the reaction mixture at 3000 ×g for 15 min at
A. Giri et al. / Food Research International 44 (2011) 739–747
4 °C, supernatant was collected and further mixed with 5 mL of 0.44 M Na2CO3 and 1 mL of 3-fold diluted Folin–Ciocalteau reagent. The resulting solution was incubated for 30 min at 30 °C, and absorbance at 660 nm was determined.
741
2.10.2. α-Amylase activity The reaction was terminated by the addition of 100 μL of 3,5dinitrosalicylic acid (DNS) reagent and heated in boiling water for 10 min. The reducing groups released from starch catalyzed/reduced
Table 1 Identification, threshold and odor descriptions of volatiles detected in squid miso during storage. RIa
Identificationb Threshold Odor descriptionc (μg/L)c
Peak Volatile compounds no.
Aldehydes 1 Acetaldehyde 2 2-Methylpropanal 4 2-Methylbutanal 5 3-Methylbutanal 14 Hexanal 27 Heptanal 33 2-Hexenal (Z) 37 4-Heptenal
692 814 912 915 1091 1199 1235 1255
MS, MS, MS, MS, MS, MS, MS, MS,
RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std
25.1 1.5 1.0 0.2 5.0 2.9 19.2 4.2
Apple skin Nutty, malty Nutty, almond Almond, nutty Fishy, grassy Dry fish, green Stink bug Biscuit, creamy
Esters 3 9 13 17 20 23 36 40
44
Octanal
1298 MS, RI, Std
0.6
Orange peel
42
59 70 76
Nonanal 2,4-Heptadienal (E,Z) 2,4-Heptadienal (E,E)
1405 MS, RI, Std 1483 MS, RI, Std 1508 MS, RI, Std
1.1 94.8 15.4
Green, tallowy Fried, fatty Fatty, hay
45 53 63 78
Strong alcoholic Plastic, pungent Green apple Solvent like Green Fragrant Burnt, meaty Alcoholic Fusel oil Rancid, pungent Fatty, fruity Green, pungent Winey, whisky Musty odor Pleasant Mashroom, herb Green, plastic Herbaceous
Peak Volatile compounds no.
1283 MS, RI, Std
75.0
Berry note, fruity
1303 1341 1444 1649
MS, RI, MS, RI, MS, RI, MS, RI,
Std Std Std Std
19.9 2.0 19.4 5.0
Fruity, sweet Banana, fruity Sweet, soapy Grape
Aromatic compounds 18 Ethyl benzene 22 p-Xylene 25 o-Xylene 28 Cymene 30 Propyl benzene 41 p-Cymene 73 Benzaldehyde 80 Ethyl benzoate 85 4-Ethyl benzaldehyde 87 Ethylphenyl acetate 88 2-Phenylethyl acetate 89 Benzyl alcohol 90 Phenylethyl alcohol 92 Phenol 93 4-Ethylguaiacol 94 4-Ethylphenol
1126 1139 1191 1209 1215 1274 1544 1683 1728 1799 1834 1893 1931 2025 2046 2195
MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI,
Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
2205.3 68.6 450.2 6.5 177.1 5.0 750.9 55.6 123.2 155.6 249.6 2546.2 564.2 5501.2 89.3 1010.1
Ethereal, floral Cold meat, oily Geranium, oily Strong aromatic Moth-ball like Gasoline, spicy Bitter almond Chamomile Fruity, anisic Honey, rose Honey, rosy Sweet floral Honey, rose Medicinal Clove, spicy Shoe polish
Sulfur 12 57 66
1081 MS, RI, Std 1389 MS, RI, Std 1476 MS, RI, Std
1.1 45.0 0.5
Cooked cabbage Cocoa, green Baked potato
1695 MS, RI, Std 1735 MS, RI, Std
51.2 856.1
950,000.0 8505.7 1259.9 6505.3 4125.0 459.2 358.1 820.5 16.0 4.0 1508.2 150.3 7.6 75.2 125.1 65.2 89.2 547.1 5.7 35.0 232.0
Green, grassy Mashroom Brandy nuance
61 64
2-Hexen-1-ol (Z) 1-Octen-3-ol
1422 MS, RI, Std 1460 MS, RI, Std
359.4 1.5
Walnut, medicinal 84 Mushroom, fishy 86
65 69 72 74 75 79
Heptanol 2-Ethyl hexanol 2-Nonanol Octanol 2,3-Butanediol (meso) 1-Nonanol
1465 1497 1525 1566 1593 1671
MS, MS, MS, MS, MS, MS,
RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std
5.5 25,482.2 8598.8 125.9 95.1 45.5
Fresh, light green Green rosy Coconut, waxy Herbaceous, fatty Fruity, onion Dusty, oily, green
Nitrogen containing compounds 47 2,3-Dimethylpyrazene 62 2,3,5-Trimethylpyrazine 68 Tetramethylpyrazine 91 2-Acetylpyrrole
1322 1438 1487 1993
MS, MS, MS, MS,
RI, Std RI, Std RI, Std RI, Std
2225.3 350.1 2525.0 58,585.3
Green, nutty Bread, burnt Fermented soy Herbal, nutty
Acids 82 2-Methylbutanoic acid
1690 MS, RI, Std
0.7
83
1693 MS, RI, Std
1560.9
b c
3-Methylbutanoic acid
MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI,
Fruity, buttery Banana, pear note Pineapple note Fruity, sweet Banana, fresh Orange, fruity Fruity, strawberry Sweet, apricot
RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI, Std RI RI, Std RI, Std RI, Std
a
890 1026 1083 1117 1133 1143 1241 1272
5.0 25.0 58.0 30.1 1.6 5.9 2.3 15.0
924 1064 1095 1103 1131 1169 1181 1214 1223 1226 1237 1263 1318 1324 1327 1330 1337 1339 1347 1367 1402 1417
MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS, MS,
Identification Threshold Odor description (μg/L) Std Std Std Std Std Std Std Std
Alcohols 6 Ethanol 11 1-Propanol 15 3-Methyl-2-butanol 16 2-Methylpropanol 19 3-Pentanol 24 1-Butanol 26 1-Penten 3-ol 29 3-Hexanol 31 2-Methyl-1-butanol 32 3-Methyl-1-butanol 34 2-Hexanol 39 1-Pentanol 46 3-Methyl-1-pentanol 48 2-Ethyl-1-butanol 49 Cyclopentanol 50 2-Heptanol 51 2-Penten-1-ol (E) 52 3-Methyl-3-buten-1-ol 55 1-Hepten-3-ol 56 Hexanol 58 3-Octanol 60 2-Hexen-1-ol (E)
Ethyl acetate 2-Methylpropyl acetate Butyl acetate Isobutyl isobutyrate Isoamyl acetate Ethyl pentanoate Ethyl hexanoate 3-Methylbutyl butanoate 2-Methylbutyl 2-methylbutanoate Isoamyl isovalerate Ethyl heptanoate Ethyl octanoate Ethyl decanoate
RIa
containing compounds Dimethyl disulfide 2,4,5-Trimethylthiazole 3-(Methylthio)propanal 2-Ethoxythiazole 3-(Methylthio)propanol
Strong, meaty Raw potato
Furans 7 2-Ethylfuran 21 2-n-Butylfuran 35 2-Pentylfuran 67 2-Furaldehyde 71 2-Acetylfuran 81 Furfuryl alcohol
956 1136 1238 1484 1510 1689
MS, RI, MS, RI, MS, RI, MS, RI, MS, RI, MS, RI,
Std Std Std Std Std Std
2.3 5.0 5.9 9562.0 15,025.2 4500.6
Rubber, pungent Noncharacteristics Green bean like Wood, almond Smoky, tobacco Burnt sugar
Ketones 8 2,3-Butanedione 10 2,3-Pentanedione 38 3-Octanone 43 2-Octanone
985 1052 1265 1295
MS, RI, MS, RI, MS, RI, MS, RI,
Std Std Std Std
0.1 5505.6 21.5 50.3
creamy, caramel Butter scotch Mashroom, harbal Soapy, floral
Sweet, cheese
54
1345 MS, RI, Std
68.0
Over ripe fruit
77
1610 MS, RI, Std
5.5
RI, retention index. MS, mass spectrum; RI, retention index; Std, confirmation by authentic. Cited from our previous investigation (Giri, Osako, Okamoto, & Ohshima, 2010).
6-Methyl-5-hepten 2-one 2-Undecanone
Sweet, fruity Tallow, musty
742
Table 2 Changes of volatile contents (μg/kg of sample) and OAVs (in parenthesis) of miso prepared from squid meat during hypobaric and temperature dependent storage. Peak Volatile compounds no. Aldehydes 1 Acetaldehyde 2 2-Methylpropanal 4 2-Methylbutanal 5 3-Methylbutanal 14 Hexanal 27 Heptanal 33 2-Hexenal (Z) 37 4-Heptenal 44 Octanal 59 Nonanal 70 2,4-Heptadienal (E,Z) 76 2,4-Heptadienal (E,E)
Esters 3 9 13 17 20 23 36
Ethyl acetate 2-Methylpropyl acetate Butyl acetate Isobutyl isobutyrate Isoamyl acetate Ethyl pentanoate Ethyl hexanoate
7.4 (0.3) 6.9 (4.6) 0.3 (0.3) 5.0 (31.7) 9.9 (2.0) 5.6 (1.9) 0.1 (b 0.1) 0.3 (0.1) 0.9 (1.6) 0.2 (0.2) 0.4 (b 0.1) 0.3 (b 0.1)
45 days storage HTa 16.4 (0.7) 9.1 (6.0) 0.9 (0.9) 6.2 (38.7) 9.0 (1.8) 17.6 (6.1) 0.2 (b 0.1) 0.3 (0.1) 1.7 (2.9) 1.1 (1.0) 4.3 (b 0.1) 0.5 (b 0.1)
90 days storage
LTb 14.7 (0.6) 8.2 (5.4) 0.3 (0.3) 5.2 (32.7) 8.4 (1.7) 6.9 (2.4) 0.2 (b 0.1) 0.2 (0.1) 0.9 (1.5) 0.2 (0.2) 2.6 (b 0.1) 0.3 (b 0.1)
LPc 9.5 (0.4) 7.4 (4.9) 0.3 (0.3) 4.9 (30.8) 6.8 (1.4) 4.4 (1.5) 0.1 (b 0.1) 0.2 (0.1) 0.7 (1.3) 0.2 (0.2) 0.4 (b 0.1) 0.3 (b 0.1)
HT 15.9 (0.6) 19.2 (12.8) 1.1 (1.1) 3.9 (24.6) 5.7 (1.1) 15.7 (5.4) 0.3 (b 0.1) 0.4 (0.1) 1.6 (2.7) 0.7 (0.7) 2.4 (b 0.1) 0.5 (b 0.1)
180 days storage
LT 17.8 (0.7) 8.6 (5.7) 0.5 (0.5) 5.0 (31.2) 3.1 (0.6) 11.1 (3.9) 0.3 (b 0.1) 0.3 (0.1) 1.4 (2.4) 0.1 (0.1) 1.9 (b 0.1) 0.2 (b 0.1)
LP
HT
16.6 (0.7) 8.2 (5.4) 0.2 (0.2) 4.4 (27.4) 4.4 (0.9) 3.3 (1.2) 0.1 (b 0.1) 0.2 (b 0.1) 0.7 (1.1) 0.2 (0.2) 0.3 (b 0.1) 0.2 (b 0.1)
23.8 (0.9) 26.1 (17.4) 1.4 (1.4) 5.2 (32.9) 4.0 (0.8) 10.9 (3.8) 0.1 (b 0.1) 0.3 (0.1) 6.3 (10.7) 0.4 (0.4) 9.6 (b 0.1) 0.5 (b 0.1)
184.1 (b 0.1) 256.8 (b 0.1) 294.4 (b 0.1) 329.7 (b 0.1) 246.2 (b 0.1) 313.1 (b 0.1) 247.1 (b 0.1) 151.3 (b 0.1) 51.1 (b 0.1) 113.1 (b 0.1) 318.8 (b 0.1) 159.6 (b 0.1) 300.6 (b 0.1) 321.2 (b 0.1) 370.4 (b 0.1) 146.4 (b 0.1) 1.0 (b 0.1) 3.1 (b 0.1) 4.3 (b 0.1) 3.5 (b 0.1) 3.5 (b 0.1) 7.3 (b 0.1) 4.5 (b 0.1) 1.9 (b 0.1) 2.2 (b 0.1) 4.8 (b 0.1) 2.7 (b 0.1) 5.2 (b 0.1) 5.2 (b 0.1) 3.9 (b 0.1) 8.6 (b 0.1) 5.5 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.4 (b 0.1) 0.2 (b 0.1) 3.3 (b 0.1) 4.7 (b 0.1) 5.1 (b 0.1) 5.9 (b 0.1) 2.7 (b 0.1) 4.5 (b 0.1) 6.7 (b 0.1) 2.7 (b 0.1) 13.1 (b 0.1) 34.8 (0.1) 55.0 (0.1) 41.6 (0.1) 24.8 (0.1) 65.3 (0.1) 29.3 (0.1) 42.6 (0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.5 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.4 (b 0.1) 0.8 (b 0.1) 3.2 (0.2) 0.4 (b 0.1) 0.5 (b 0.1) 3.5 (0.2) 0.6 (b 0.1) 0.5 (b 0.1) 43.4 (10.8) 86.5 (21.5) 104.3 (26.0) 123.3 (30.7) 151.6 (37.8) 98.0 (24.4) 114.5 (28.5) 180.3 (44.9) 2.2 (b 0.1) 1.4 (b 0.1) 0.6 (b 0.1) 2.7 (b 0.1) 0.6 (b 0.1) 0.5 (b 0.1) 2.1 (b 0.1) 0.5 (b 0.1) 0.9 (b 0.1) 1.7 (b 0.1) 1.4 (b 0.1) 1.7 (b 0.1) 3.0 (b 0.1) 3.7 (b 0.1) 2.6 (b 0.1) 2.4 (b 0.1) 0.7 (0.1) 1.4 (0.2) 0.8 (0.1) 0.9 (0.1) 0.7 (0.1) 1.2 (0.2) 1.3 (0.2) 1.1 (0.2) 0.3 (b 0.1) 0.5 (b 0.1) 0.3 (b 0.1) 0.4 (b 0.1) 0.5 (b 0.1) 0.4 (b 0.1) 0.6 (b 0.1) 0.7 (b 0.1) 0.3 (b 0.1) 0.7 (b 0.1) 0.3 (b 0.1) 0.6 (b 0.1) 0.6 (b 0.1) 0.4 (b 0.1) 0.7 (b 0.1) 0.8 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 1.1 (b 0.1) 1.1 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 0.7 (b 0.1) 0.2 (b 0.1) 0.6 (b 0.1) 0.7 (b 0.1) 0.3 (b 0.1) 1.0 (b 0.1) 0.3 (b 0.1) 0.4 (b 0.1) 1.2 (b 0.1) 0.6 (b 0.1) 0.8 (b 0.1) 3.9 (b 0.1) 5.5 (b 0.1) 4.7 (b 0.1) 4.5 (b 0.1) 0.1 0.1 0.1 0.2 0.2 0.1 0.2 0.1 0.2 (b 0.1) 0.4 (0.1) 0.6 (0.1) 0.5 (0.1) 0.6 (0.1) 0.3 (0.1) 0.7 (0.1) 0.4 (0.1) 0.0 (b 0.1) 0.2 (b 0.1) 0.0 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.0 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.4 (b 0.1) 0.3 (b 0.1) 0.4 (b 0.1) 0.4 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.9 (0.6) 2.7 (1.8) 1.1 (0.7) 1.8 (1.2) 3.0 (2.0) 1.0 (0.7) 2.6 (1.7) 4.3 (2.8) 0.9 (0.2) 1.7 (0.3) 1.8 (0.3) 2.0 (0.4) 1.1 (0.2) 1.9 (0.4) 1.8 (0.3) 1.5 (0.3) 10.1 (b 0.1) 15.3 (b 0.1) 10.5 (b 0.1) 12.2 (b 0.1) 8.0 (b 0.1) 14.2 (b 0.1) 17.7 (b 0.1) 4.9 (b 0.1) 4.8 (b 0.1) 5.9 (b 0.1) 3.1 (b 0.1) 4.3 (b 0.1) 5.6 (b 0.1) 3.1 (b 0.1) 4.1 (b 0.1) 3.0 (b 0.1) 0.7 (b 0.1) 0.9 (b 0.1) 0.5 (b 0.1) 0.7 (b 0.1) 0.9 (b 0.1) 0.4 (b 0.1) 0.8 (b 0.1) 1.5 (b 0.1) 0.9 (b 0.1) 8.5 (0.1) 0.8 (b 0.1) 8.3 (0.1) 8.6 (0.1) 1.7 (b 0.1) 10.8 (0.1) 11.0 (0.1) 0.7 (b 0.1) 1.3 (b 0.1) 0.8 (b 0.1) 1.4 (b 0.1) 1.3 (b 0.1) 0.9 (b 0.1) 1.6 (b 0.1) 1.9 (b 0.1)
0.7 (0.1) 0.8 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.4 (0.3) 4.7 (0.8) 0.1 (0.1)
2.1 (0.4) 0.9 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.3 (0.2) 8.7 (1.5) 0.3 (0.1)
1.1 (0.2) 0.9 (b 0.1) 0.1 (b 0.1) 0.0 (b 0.1) 0.2 (0.2) 9.4 (1.6) 0.1 (b 0.1)
2.7 (0.5) 1.0 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.5 (0.3) 8.2 (1.4) 0.2 (0.1)
2.7 (0.5) 0.4 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.3 (0.2) 4.0 (0.7) 0.3 (0.1)
1.1 (0.2) 0.8 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.3 (0.2) 10.0 (1.7) 0.1 (0.1)
4.1 (0.8) 1.1 (b 0.1) 0.1 (b 0.1) 0.3 (b 0.1) 0.6 (0.4) 7.5 (1.3) 0.4 (0.2)
4.4 (0.9) 0.4 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.3 (0.2) 2.9 (0.5) 0.2 (0.1)
270 days storage
LT 19.9 10.3 0.6 5.4 3.9 10.0 0.4 0.2 2.0 0.2 3.1 0.5
LP (0.8) (6.8) (0.6) (34.2) (0.8) (3.5) (b 0.1) (b 0.1) (3.4) (0.2) (b 0.1) (b 0.1)
241.0 (b 0.1) 452.5 (0.1) 3.8 (b 0.1) 4.0 (b 0.1) 1.2 (b 0.1) 5.6 (b 0.1) 136.9 (0.3) 0.4 (b 0.1) 4.9 (0.3) 101.8 (25.4) 1.3 (b 0.1) 4.7 (b 0.1) 1.2 (0.2) 0.7 (b 0.1) 0.5 (b 0.1) 0.6 (b 0.1) 0.2 (b 0.1) 9.2 (b 0.1) 0.1 0.2 (b 0.1) 0.1 (b 0.1) 0.4 (b 0.1) 0.2 (b 0.1) 1.2 (0.8) 1.6 (0.3) 22.5 (b 0.1) 1.5 (b 0.1) 0.3 (b 0.1) 3.0 (b 0.1) 1.5 (b 0.1)
1.1 0.9 0.1 0.4 0.3 10.7 0.2
(0.2) (b 0.1) (b 0.1) (b 0.1) (0.2) (1.8) (0.1)
HT
27.8 7.7 0.3 4.5 2.5 2.4 0.1 0.2 0.6 0.2 0.3 0.2
25.1 (1.0) 8.1 (5.4) 0.3 (0.3) 3.2 (19.9) 2.7 (0.5) 1.7 (0.6) 0.1 (b 0.1) 0.1 (b 0.1) 0.6 (1.0) 0.2 (0.2) 0.4 (b 0.1) 0.2 (b 0.1)
97.9 (b 0.1) 106.9 (b 0.1) 203.9 (b 0.1) 174.4 (b 0.1) 44.7 (b 0.1) 13.9 (b 0.1) 2.6 (b 0.1) 2.6 (b 0.1) 2.9 (b 0.1) 5.9 (b 0.1) 4.4 (b 0.1) 3.6 (b 0.1) 0.4 (b 0.1) 0.2 (b 0.1) 7.5 (b 0.1) 4.4 (b 0.1) 1.2 (b 0.1) 2.4 (b 0.1) 28.8 (0.1) 31.7 (0.1) 46.1 (0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.2 (b 0.1) 1.3 (0.1) 57.1 (14.2) 450.6 (112.3) 29.3 (7.3) 1.5 (b 0.1) 0.2 (b 0.1) 1.4 (b 0.1) 2.7 (b 0.1) 3.3 (b 0.1) 1.9 (b 0.1) 1.1 (0.1) 0.8 (0.1) 0.0 (b 0.1) 0.9 (b 0.1) 0.6 (b 0.1) 0.4 (b 0.1) 0.9 (b 0.1) 0.5 (b 0.1) 0.3 (b 0.1) 2.1 (b 0.1) 0.2 (b 0.1) 0.4 (b 0.1) 0.7 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 3.5 (b 0.1) 5.3 (b 0.1) 0.6 (b 0.1) 0.2 0.1 0.1 0.6 (0.1) 0.2 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.0 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 3.4 (2.2) 9.3 (6.1) 1.4 (0.9) 1.7 (0.3) 1.7 (0.3) 1.2 (0.2) 13.7 (b 0.1) 9.3 (b 0.1) 7.8 (b 0.1) 3.4 (b 0.1) 2.5 (b 0.1) 1.2 (b 0.1) 0.7 (b 0.1) 0.8 (b 0.1) 0.3 (b 0.1) 9.8 (0.1) 8.9 (0.1) 4.7 (b 0.1) 2.5 (0.1) 1.8 (b 0.1) 1.4 (b 0.1)
62.3 (b 0.1) 107.6 (b 0.1) 1.9 (b 0.1) 5.0 (b 0.1) 0.3 (b 0.1) 2.2 (b 0.1) 13.7 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 19.8 (4.9) 0.6 (b 0.1) 2.7 (b 0.1) 0.6 (0.1) 0.9 (b 0.1) 0.8 (b 0.1) 1.8 (b 0.1) 0.7 (b 0.1) 2.3 (b 0.1) 0.2 0.5 (0.1) 0.1 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 3.4 (2.2) 1.5 (0.3) 12.2 (b 0.1) 1.8 (b 0.1) 0.6 (b 0.1) 9.2 (0.1) 2.3 (0.1)
(1.2) (b 0.1) (b 0.1) (b 0.1) (0.3) (1.1) (0.2)
15.4 24.0 1.5 4.7 4.7 2.7 0.1 0.2 7.7 0.3 3.0 0.5
6.5 0.3 0.1 0.2 0.2 0.1 0.2
(0.6) (16.0) (1.4) (29.8) (0.9) (0.9) (b 0.1) (0.1) (13.0) (0.3) (b 0.1) (b 0.1)
LP (0.1) (5.8) (0.7) (22.2) (1.2) (3.0) (b 0.1) (b 0.1) (1.2) (0.2) (b 0.1) (b 0.1)
6.0 1.1 0.1 0.5 0.4 6.2 0.4
(1.1) (5.1) (0.3) (28.1) (0.5) (0.8) (b 0.1) (b 0.1) (1.0) (0.2) (b 0.1) (b 0.1)
LT
(1.3) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.1)
2.9 8.7 0.7 3.5 6.2 8.7 0.2 0.1 0.7 0.2 2.5 0.2
0.7 1.2 0.1 3.3 0.3 7.6 0.1
(0.1) (b 0.1) (b 0.1) (0.1) (0.2) (1.3) (b 0.1)
7.0 (1.4) 1.1 (b 0.1) 0.1 (b 0.1) 0.6 (b 0.1) 0.4 (0.3) 4.9 (0.8) 0.3 (0.1)
A. Giri et al. / Food Research International 44 (2011) 739–747
Alcohols 6 Ethanol 11 1-Propanol 15 3-Methyl-2-butanol 16 2-Methylpropanol 19 3-Pentanol 24 1-Butanol 26 1-Penten 3-ol 29 3-Hexanol 31 2-Methyl-1-butanol 32 3-Methyl-1-butanol 34 2-Hexanol 39 1-Pentanol 46 3-Methyl-1-pentanol 48 2-Ethyl 1-butanol 49 Cyclopentanol 50 2-Heptanol 51 2-Penten-1-ol (E) 52 3-Methyl-3-buten-1-ol 55 1-Hepten-3-ol 56 Hexanol 58 3-Octanol 60 2-Hexen-1-ol (E) 61 2-Hexen-1-ol (Z) 64 1-Octen-3-ol 65 Heptanol 69 2-Ethyl hexanol 72 2-Nonanol 74 Octanol 75 2,3-Butanediol (meso) 79 1-Nonanol
Matured miso
40 42
3-Methylbutyl 2-Methylbutyl 2methylbutanoate Isoamyl isovalerate Ethyl heptanoate Ethyl octanoate Ethyl decanoate
0.9 0.6 1.0 14.2
Ketones 8 2,3-Butanedione 10 2,3-Pentanedione 38 3-Octanone 43 2-Octanone 54 6-Methyl-5-hepten 2-one 77 2-Undecanone
1.7 215.3 1.1 0.2 0.5 1.0
45 53 63 78
Sulfur 12 57 66 84 86
containing compounds Dimethyl disulfide 2,4,5-Trimethylthiazole 3-(Methylthio)-propanal 2-Ethoxythiazole 3-(Methylthio)-propanol
Nitrogen containing compounds 47 2,3-Dimethylpyrazene 62 2,3,5-Trimethylpyrazine 68 Tetramethylpyrazine 91 2-Acetylpyrrole Aromatic compounds 18 Ethyl benzene 22 p-Xylene 25 o-Xylene 28 Cymene 30 Propyl benzene 41 p-Cymene 73 Benzaldehyde 80 Ethyl benzoate 85 4-Ethyl benzaldehyde 87 Ethylphenyl acetate 88 2-Phenylethyl acetate 89 Benzyl alcohol 90 Phenylethyl alcohol 92 Phenol 93 4-Ethylguaiacol 94 4-Ethylphenol Acids 82 2-Methylbutanoic acid 83 3-Methylbutanoic acid a b
HT, atmospheric pressure at 25 °C. LT, atmospheric pressure at 10 °C. LP, hypobaric 10 kPa at 25 °C.
1.9 4.6 4.4 66.4
(0.1) (2.3) (0.2) (13.2)
0.1 (b 0.1) 0.3 (b 0.1) 1.3 2.1 2.0 14.0
(0.1) (1.0) (0.1) (2.8)
0.3 (b 0.1) 0.3 (b 0.1) 1.4 2.9 3.9 61.3
(0.1) (1.5) (0.2) (12.2)
0.4 (b 0.1) 0.2 (b 0.1) 1.4 5.8 1.6 69.3
(0.1) (2.9) (0.1) (13.8)
0.1 (b 0.1) 0.2 (b 0.1) 1.8 2.8 2.9 17.6
(0.1) (1.4) (0.2) (3.5)
0.4 (b 0.1) 0.3 (b 0.1) 2.1 5.2 5.3 80.4
(0.1) (2.6) (0.3) (16.0)
0.3 (b 0.1) 0.2 (b 0.1) 1.3 5.3 1.3 73.8
(0.1) (2.7) (0.1) (14.7)
(29.2) 2.1 (36.4) 1.8 (30.7) 2.5 (42.2) 2.3 (38.5) 3.6 (60.3) 2.7 (45.8) 2.8 (48.1) (b 0.1) 423.7 (0.1) 261.2 (b 0.1) 229.5 (b 0.1) 311.1 (0.1) 406.1 (0.1) 166.1 (b 0.1) 176.9 (b 0.1) (0.1) 1.1 (b 0.1) 0.8 (b 0.1) 0.7 (b 0.1) 1.2 (0.1) 1.3 (0.1) 0.6 (b 0.1) 1.0 (b 0.1) (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) (b 0.1) 2.0 (b 0.1) 0.6 (b 0.1) 0.3 (b 0.1) 2.2 (b 0.1) 1.1 (b 0.1) 0.4 (b 0.1) 1.4 (b 0.1) (0.2) 5.9 (1.1) 0.9 (0.2) 1.0 (0.2) 6.0 (1.1) 0.8 (0.1) 1.1 (0.2) 12.8 (2.3)
0.2 (b 0.1) 0.2 (b 0.1) 2.1 (0.1) 3.2 (1.6) 2.5 (0.1) 19.8 (3.9)
5.6 (95.7) 357.7 (0.1) 1.8 (0.1) 0.1 (b 0.1) 1.6 (b 0.1) 0.9 (0.2)
0.4 (b 0.1) 0.3 (b 0.1)
0.4 (b 0.1) 0.2 (b 0.1)
0.1 (b 0.1) 0.2 (b 0.1)
0.4 (b 0.1) 0.3 (b 0.1)
2.3 (0.1) 7.1 (3.6) 4.9 (0.3) 77.4 (15.4)
1.0 (0.1) 4.7 (2.4) 1.2 (0.1) 71.1 (14.2)
0.5 (b 0.1) 4.9 (2.5) 1.4 (0.1) 34.8 (6.9)
2.2 6.7 4.8 84.3
(0.1) (3.4) (0.2) (16.8)
1.7 (28.0) 2.1 (36.1) 120.6 (b 0.1) 115.2 (b 0.1) 0.5 (b 0.1) 0.7 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.3 (b 0.1) 0.6 (b 0.1) 0.9 (0.2) 15.1 (2.7)
2.9 (48.7) 95.9 (b 0.1) 0.7 (b 0.1) 0.1 (b 0.1) 2.2 (b 0.1) 0.7 (0.1)
1.0 52.3 0.4 0.1 0.3 0.6
(17.2) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1)
0.5 0.2 0.9 0.2 0.3 3.2
(0.2) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
0.8 0.2 1.6 0.4 0.3 9.5
(0.3) (b 0.1) (0.3) (b 0.1) (b 0.1) (b 0.1)
0.7 0.2 1.1 0.2 0.3 3.6
(0.3) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
0.5 0.2 1.0 0.4 0.3 9.3
(0.2) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
0.9 0.3 1.7 1.3 0.4 10.1
(0.4) (0.1) (0.3) (b 0.1) (b 0.1) (b 0.1)
1.9 0.2 1.2 0.5 0.3 7.4
(0.8) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
0.6 0.2 0.9 1.6 0.3 11.9
(0.3) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
1.1 0.3 1.4 2.1 0.3 12.6
(0.5) (0.1) (0.2) (b 0.1) (b 0.1) (b 0.1)
3.2 (1.4) 0.2 (b 0.1) 0.9 (0.2) 0.6 (b 0.1) 0.3 (b 0.1) 8.7 (b 0.1)
0.7 (0.3) 0.2 (b 0.1) 1.0 (0.2) 3.1 (b 0.1) 0.3 (b 0.1) 15.2 (b 0.1)
0.9 (0.4) 0.3 (0.1) 1.8 (0.3) 2.9 (b 0.1) 0.4 (b 0.1) 21.6 (b 0.1)
1.7 (0.7) 0.2 (b 0.1) 1.2 (0.2) 0.6 (b 0.1) 0.4 (b 0.1) 8.7 (b 0.1)
0.5 0.2 0.8 3.4 0.2 26.1
(0.2) (b 0.1) (0.1) (b 0.1) (b 0.1) (b 0.1)
2.0 0.2 15.7 0.5 1.4
(1.8) (b 0.1) (34.2) (b 0.1) (b 0.1)
2.4 0.5 27.1 0.9 1.9
(2.3) (b 0.1) (59.1) (b 0.1) (b 0.1)
2.3 0.2 18.3 0.7 2.8
(2.2) (b 0.1) (39.9) (b 0.1) (b 0.1)
0.9 0.2 14.0 0.8 2.7
(0.8) (b 0.1) (30.7) (b 0.1) (b 0.1)
0.9 0.9 42.2 1.0 8.4
(0.8) (b 0.1) (92.1) (b 0.1) (b 0.1)
0.5 0.2 21.2 1.1 7.7
(0.5) (b 0.1) (46.3) (b 0.1) (b 0.1)
0.3 0.2 13.9 0.9 4.7
(0.3) (b 0.1) (30.3) (b 0.1) (b 0.1)
0.5 0.7 65.1 2.8 10.5
(0.5) (b 0.1) (142.2) (b 0.1) (b 0.1)
0.6 (0.6) 0.2 (b 0.1) 83.0 (181.2) 1.2 (b 0.1) 6.3 (b 0.1)
0.3 (0.3) 0.2 (b 0.1) 12.4 (27.1) 1.4 (b 0.1) 6.8 (b 0.1)
0.1 (0.1) 0.5 (b 0.1) 83.0 (181.2) 7.0 (b 0.1) 9.7 (b 0.1)
0.1 (0.1) 0.2 (b 0.1) 98.0 (213.9) 1.6 (b 0.1) 5.6 (b 0.1)
0.1 0.2 10.6 2.5 6.8
(0.1) (b 0.1) (23.2) (b 0.1) (b 0.1)
0.1 0.1 0.1 3.1
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 2.0 0.1 2.5
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 0.1 0.1 3.7
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 0.6 0.1 3.5
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 1.1 0.1 2.8
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 0.1 0.1 3.8
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.1 0.7 0.1 4.2
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
3.0 0.5 0.1 3.8
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
1.2 (b 0.1) 0.6 (b 0.1) 0.1 (b 0.1) 6.1 (b 0.1)
0.1 (b 0.1) 0.6 (b 0.1) 0.1 (b 0.1) 6.0 (b 0.1)
4.4 (b 0.1) 0.3 (b 0.1) 0.2 (b 0.1) 9.9 (b 0.1)
0.1 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 3.5 (b 0.1)
0.1 0.9 0.1 7.3
(b 0.1) (b 0.1) (b 0.1) (b 0.1)
0.0 0.2 0.2 0.1 0.2 0.1 4.4 5.0 0.1 1.1 1.1 0.3 67.3 0.4 17.2 0.1
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.2) (b 0.1)
0.0 0.1 0.5 0.1 0.2 0.0 7.5 9.1 0.1 1.6 3.3 0.9 73.8 0.8 26.7 1.4
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.3) (b 0.1)
0.2 0.1 0.7 0.2 0.4 0.0 5.3 2.7 0.1 1.4 1.2 0.3 52.0 0.6 16.6 0.1
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.2) (b 0.1)
0.0 0.1 0.2 0.0 0.0 0.0 4.0 6.3 0.1 1.5 3.3 0.8 91.0 0.5 22.2 1.5
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (0.2) (b 0.1)
0.3 0.1 0.4 0.1 0.1 0.0 7.6 6.0 0.1 3.8 9.0 1.4 99.6 1.3 37.6 1.9
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (0.4) (b 0.1)
0.2 0.1 1.0 0.2 0.1 0.0 6.4 1.8 0.1 1.4 1.5 0.3 47.7 0.7 18.6 1.1
(b 0.1) 0.0 (b 0.1) (b 0.1) 0.1 (b 0.1) (b 0.1) 0.1 (b 0.1) (b 0.1) 0.0 (b 0.1) (b 0.1) 0.0 (b 0.1) (b 0.1) 0.0 (b 0.1) (b 0.1) 2.8 (b 0.1) (b 0.1) 8.9 (0.2) (b 0.1) 0.1 (b 0.1) (b 0.1) 1.9 (b 0.1) (b 0.1) 9.6 (b 0.1) (b 0.1) 1.6 (b 0.1) (0.1) 116.2 (0.2) (b 0.1) 1.1 (b 0.1) (0.2) 24.7 (0.3) (b 0.1) 2.1 (b 0.1)
0.2 0.2 0.6 0.1 0.1 0.0 12.4 12.5 0.1 7.2 11.3 1.5 95.7 1.9 51.8 2.4
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (0.2) (b 0.1) (0.6) (b 0.1)
0.8 (b 0.1) 0.1 (b 0.1) 2.2 (b 0.1) 0.2 (b 0.1) 0.4 (b 0.1) 0.3 (b 0.1) 7.2 (b 0.1) 2.7 (b 0.1) 0.1 (b 0.1) 1.6 (b 0.1) 1.5 (b 0.1) 0.8 (b 0.1) 39.4 (0.1) 1.0 (b 0.1) 19.8 (0.2) 1.8 (b 0.1)
0.0 (b 0.1) 1.7 (b 0.1) 0.1 (b 0.1) 0.2 (b 0.1) 0.1 (b 0.1) 0.5 (b 0.1) 0.1 (b 0.1) 0.3 (b 0.1) 0.1 (b 0.1) 0.1 (b 0.1) 0.0 (b 0.1) 0.1 (b 0.1) 2.0 (b 0.1) 15.2 (b 0.1) 8.1 (0.1) 18.5 (0.3) 0.1 (b 0.1) 0.2 (b 0.1) 3.2 (b 0.1) 9.9 (0.1) 12.8 (0.1) 11.7 (b 0.1) 2.2 (b 0.1) 1.5 (b 0.1) 121.4 (0.2) 115.2 (0.2) 1.4 (b 0.1) 1.9 (b 0.1) 30.2 (0.3) 84.9 (1.0) 2.6 (b 0.1) 2.8 (b 0.1)
0.3 (b 0.1) 0.2 (b 0.1) 1.4 (b 0.1) 0.4 (0.1) 0.7 (b 0.1) 0.7 (b 0.1) 8.9 (11.1) 1.7 (b 0.1) 0.1 (b 0.1) 1.6 (b 0.1) 1.2 (b 0.1) 0.3 (b 0.1) 65.3 (0.1) 1.3 (b 0.1) 18.6 (0.2) 1.9 (b 0.1)
0.0 0.1 0.2 0.1 0.1 0.1 2.0 7.7 0.1 4.6 12.9 2.3 133.3 1.6 44.2 3.2
(b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (b 0.1) (2.8) (0.1) (b 0.1) (b 0.1) (0.1) (b 0.1) (0.2) (b 0.1) (0.5) (b 0.1)
3.5 (5.5) 0.5 (b 0.1)
0.3 (0.5) 0.2 (b 0.1)
0.8 (1.2) 0.0 (b 0.1)
0.9 (1.5) 0.3 (b 0.1)
0.1 (0.1) 0.0 (b 0.1)
0.1 (0.2) 0.1 (b 0.1)
1.4 (2.2) 0.4 (b 0.1)
0.1 (0.2) 0.1 (b 0.1)
0.3 (0.4) 0.2 (b 0.1)
0.6 (0.9) 0.3 (b 0.1)
5.4 (8.6) 0.6 (b 0.1)
0.8 (1.2) 0.2 (b 0.1)
0.5 (0.8) 0.4 (b 0.1)
743
c
(b 0.1) (0.3) (0.1) (2.3)
0.4 (b 0.1) 0.3 (b 0.1)
A. Giri et al. / Food Research International 44 (2011) 739–747
Furans 7 2-Ethylfuran 21 2-n-Butylfuran 35 2-Pentylfuran 67 2-Furaldehyde 71 2-Acetylfuran 81 Furfuryl alcohol
0.2 (b 0.1) 0.2 (b 0.1)
744
A. Giri et al. / Food Research International 44 (2011) 739–747
DNS and amylase activity were monitored spectrophotometrically at 540 nm after cooling in ice for 5 min. 2.10.3. Lipase activity The reaction was stopped with a SDS-fast blue BB salt (1.4 and 0.2%, respectively) solution. The diazo-1-naphthol hydrolyzed product was monitored at 600 nm after incubating at 35 °C for 5 min. The production of soluble protein, reducing sugars, and 1-naphthol was used as the respective indices of the enzyme activities under different experimental conditions. 2.11. Sensory evaluation Flavor profile characterization of squid miso was performed in the Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Japan. The panel has previous experiences of evaluating sensory perception of several Japanese fermented food products. Training of the panel for characterizing newly developed squid miso samples was conducted over two, threehour sessions in isolated booths at room temperature and under mild light (British Standard Institution Assessors for Sensory Analysis, 1993). Based on the consistency during training period 16 sensory panelists were selected. The panel was well introduced about flavor profiles of several traditional miso products. The 90 days fermented matured squid miso and 270 days stored products under different conditions kept at −80 °C were thawed overnight at 5 °C and the samples were stabilized at serving temperature of 40 °C for 30 min just before evaluation. Undiluted coded miso samples of 5 g were introduced to the panelists in random order in porcelain plates of similar size. The attributes that best described the fermented miso aroma characteristics were selected by the panelists. From these attributes, five consensual odor descriptors including “fishy,” “nutty,” “cheesy,” “fruity” and “meaty” were established. The odor intensity of each attribute was rated on the following scale: −2, very weak; −1, weak; 0, moderate; + 1, strong; + 2, very strong. This experiment was conducted once and the data was analyzed based on the observations of 16 sensory panelists. 2.12. Statistical analysis The results for the volatile compounds were reported as mean values. Analyses were performed in triplicate. Enzyme activity data sets were evaluated by analysis of variance (ANOVA). A statistically significant difference was identified at the 95% confidence level. Posthoc mean comparisons were made on the basis of the P values (α = 0.05) by using Duncan's multiple range test. 3. Results and discussion 3.1. Changes of volatile compounds in squid miso during storage A total of 94 headspace volatile compounds isolated and detected by a combination of a Tenax TA trap and GC-FID were identified and quantified as shown in Tables 1 and 2, respectively. The volatile classes included aldehydes, alcohols, esters, ketones, furans, sulfurs, nitrogenous compounds, aromatic compounds, and volatile acids. The OAVs, obtained by dividing the concentration of each compound by its odor threshold in water, were used to assess the relative importance of individual odorants to the aroma profile of the squid miso products. Changes in volatile classes are presented in Fig. 1. The volatile aldehydes acetaldehyde, 2-methylpropanal, 3methylbutanal, hexanal, heptanal, and octanal were prominent compounds detected throughout the storage periods. Considering the higher OAVs, 2-methylpropanal (nutty, malty), 3-methylbutanal (almond, nutty), hexanal (fishy, grassy), heptanal (dry fish), and octanal (fatty, pungent) might significantly contribute to the aroma of the miso
prepared from squid meat. Among the aldehydes, 2-methylpropanal and 3-methylbutanal generally originate from the Strecker degradation of amino acids (Belitz & Grosch, 1987; Dwivedi, 1975) and were reported to produce in several meat fermented products including sausage (Olivares, Navarro, & Flores, 2009). However, hexanal, heptanal, and octanal are generated as a result of lipid oxidation during fermentation and storage. A rapid increase in aldehyde formation was observed during HT-Atm storage. Most of the Strecker-degraded aldehydes with nutty nuance increased rapidly. Lipid oxidation products increased in the early days of storage and tended to decrease after 90 days of storage. In contrast, both the LT-Atm and HT-Hypobaric storage retarded aldehyde production. This is probably due to the effect of low storage temperature as well as the hypobaric condition, in which the oxygen availability is limited. Comparative studies of LT-Atm and HT-Hypobaric storage conditions revealed that hypobaric storage could potentially prevent aldehyde production, although a higher storage temperature was maintained. The contents of alcohols including ethanol, 1-propanol, 1-penten3-ol, 3-methyl-1-butanol, and 2-ethyl hexanol increased until 90 days of storage and then decreased gradually. Considering the OAVs, most of the volatile alcohols had less impact on squid miso aroma. However, 3-methyl-1-butanol (balsamic), 1-octen-3-ol (mushroom, fishy), and heptanol (fresh, nutty), with lower threshold values, might have contributed to the aroma of the squid miso. Among these, the formation of 3-methyl-1-butanol was prevented by both lowtemperature and low-pressure conditions. The content of esters gradually increased during the storage period irrespective of storage conditions. However, ester production was relatively higher during HT-Hypobaric storage. Alcohol acyltransferase is mainly involved in the formation of volatile esters, transferring the acetyl moiety from acetyl CoA formed via the β-oxidation of fatty acids to an alcohol substrate (Sanz, Olias, & Perez, 1997). Berna et al. (2007) also reported that high partial pressure of oxygen (e.g., 100, 80, and 60 kPa) without CO2 suppressed the biosynthesis of ethyl acetate in strawberries, suggesting a role of hypobaric storage on volatile ester production. Considering the threshold values, ethyl acetate, isoamyl acetate, ethyl pentanoate, and long-chain fatty acid ethyl esters appeared to influence the sweet fruity aroma of the fish miso products. During storage, ketones were more stabilized under the hypobaric condition than under low temperature storage. During HT-Atm and LT-Atm storage, ketone formation was promoted, although it later showed a drastic reduction. Ketones are mainly produced by of lipid auto oxidation and/or amino acid degradation by the Strecker reaction (Thomas, Dimick, & McNeil, 1971). 2,3-Pentanedione was distinct among ketones in the fish miso. Considering the OAVs, however, 2,3-butanedione contributed a creamy or cheesy aroma to the squid miso. The production of furans and their derivatives appeared to be controlled during LT-Atm storage. In contrast, during both HT-Atm and HT-Hypobaric storage, the analogues of furan increased gradually in concentration. Interestingly, during HT-Hypobaric storage, furan analogues such as 2-furaldehydes and furfuryl alcohols increased rapidly in concentration rather than simple furans. This is probably due to the occurrence of dehydration, which takes place at much higher rates in the hypobaric condition (Fig. 2). Furans have been found in dehydrated or fermented condensates of carbohydrates or are formed by the Amadori rearrangement pathways (Whistler & Daniel, 1985). The results for sulfur-containing compounds clearly revealed that the HT-Hypobaric storage condition used in the present study could suppress the formation of certain volatile compounds during storage. Dimethyl disulfide (cooked cabbage) and 3-(methylthio)propanal (methional) (baked potato, meaty) contributed significant aroma to the squid miso. The amount of methional gradually increased during HT-Atm and LT-Atm storage. The contents of dimethyl trisulfide
Concentration (ug/kg) Concentration (ug/kg) Concentration (ug/kg)
A. Giri et al. / Food Research International 44 (2011) 739–747
HT-Atm 100
1100
Aldehydes
LT-Atm 1100
Alcohols
50
550
550
0
0
0
500
40
Ketones
110
Furans
250
20
55
0
0
0
16
300
Nitrogen containing compounds
0
0
90
180
270
Storage period (day)
0
Acids
4
150
8
HT-Hypobaric Esters
Sulfur containing compounds
8
Aromatic compounds
745
0
90
180
270
Storage period (day)
0
0
90
180
270
Storage period (day)
Fig. 1. Changes of volatile classes during the storage period of fish miso prepared from common squid meat under different storage conditions.
tended to decrease throughout the storage period. These sulfur compounds have previously been reported in fermented bean and fish paste products (Landaud, Helinck, & Bonnarme, 2008) and can be generated either from raw materials or during the fermentation process from free, peptidic, and proteinic sulfur amino acids, as well as glutathione pools in the fish tissue (Herbert & Shewan, 1976). Nitrogen-containing compounds and aromatic compounds present in squid miso have less impact on the aroma of the end product in terms of the relative proportion and OAVs. They are generally formed through the Maillard reaction (Fox & Wallace, 1997) during fermentation and catabolism of aromatic amino acids, respectively (Marilley & Casey, 2004). 2-Methylbutanoic acid and 3-methylbutanoic acid in squid miso rapidly increased during HT-Atm storage. However, volatile acid
production was controlled by both LT-Atm and HT-Hypobaric storage. Among the volatile acids, 2-methylbutanoic acid, due to its lower threshold value, might have contributed a cheesy aroma to the fish miso. Organoleptic perception of the matured squid miso and the stored products under different storage conditions evaluated by panels were presented in Fig. 3. The panel consensually described the products with characteristic cheesy, nutty, meaty, fruity and fishy aroma. The panel expressed the acceptability to the matured miso product prepared from the squid meat considering the similarities to the traditional miso products with enhanced cheesy and sweet aroma. As expected, room temperature storage (HT-Atm) as well as low temperature storage (LT-Atm) at atmospheric pressure, the organoleptic perception has been changed particularly for “nutty,” “fishy”
O CH2OH Furfuryl alcohol H2
CHO
Carbohydrate
Hydrolysis
(CHOH)3 CH2OH
Dehydration (-3H2O)
O CHO
Aldol condensation Furfural
Pentose sugar Oxide catalyst
O
Furan Fig. 2. Hypothetical pathway of furan and related compounds formation during storage of fish miso prepared from common squid meat under different storage conditions.
746
A. Giri et al. / Food Research International 44 (2011) 739–747
2 1 0
Fishy
Fruity
-1
Protease activity (eqv. tyrosine micromol/g)
40
Nutty
HT-Atm HT-Hypobaric HT-Atm-Hypoxic LT-Atm LT-Hypobaric
30
20 a,b a
10
0
a
a
0
a,b
a,b
a
a a
d
d
c b,c b
b a,b a,b a a
a
a
a
20
b
40
b
a,b a
a,b
a
a
a,b a a
60
Incubation period (hours)
Cheesy
Before storage LT-Atm (after storage)
HT-Atm (after storage) HT-Hypobaric (after storage)
Fig. 3. Organoleptic scores for matured fermented squid miso and 270 days stored products under different conditions.
and “meaty” aroma attributes. This was probably due to the development of volatile aldehydes, ketones, sulfur and nitrogencontaining compounds. In contrast, the results revealed no significant difference under the HT-Hypobaric condition even after 270 days of storage. The findings of the present study clearly indicated that the effect of hypobaric storage even at room temperature can significantly maintain the sincineration in order to preserve the aroma attributes. 3.2. In vitro evaluation of different storage conditions on the enzyme activities Freshly prepared koji was used as a source of crude enzymes for the analysis of in vitro enzyme assay. Changes in enzyme activity during the fermentation period are shown in Fig. 4. The results clearly indicated that a significant amount of enzymes, including proteases, lipases, and amylases, were produced after an incubation period of 48 h under the present fermentation conditions. The results of the in vitro enzyme assays clearly indicated that casein was hydrolyzed gradually after 20 h by the proteases in koji when the temperature was maintained at 25 °C (Fig. 5). The hydrolysis of protein appeared to slow down under both hypobaric and hypoxic conditions after 40 h of incubation, although the protease enzyme activity still maintained an increasing pattern at atmospheric pressure. From these findings, it can be concluded that the application of hypobaric storage can significantly reduce protease activity even at low temperature. This is probably due to the lower concentration of residual oxygen in the system rather than hypobaric stress, as the atmospheric hypoxic storage condition produced a similar pattern of protein hydrolysis. In addition, no significant changes occurred
Enzyme activity (U/g)
500 Protease Amylase Lipase
400 300
## ##
200
++
100
**
#+
0
+++ ##
+++
**
**
* 0
1
2
3
Fig. 5. In vitro enzyme activity of protease extracted from koji at different storage conditions. Comparisons were among the different treatments at the certain incubation time. Different letters indicate statistical differences (p b 0.05).
between atmospheric and hypobaric conditions in terms of protease activity at the lower storage temperature of 10 °C. This result suggests that in the present storage condition of 10 °C, the effect of the hypobaric condition might be suppressed by the effect of low storage temperature on protease enzyme activity. On the other hand, lipase activity on 1-naphthyl acetate increased during initial incubation period of 6 h and liberated 1-napthol (Fig. 6). The release of 1-napthol increased significantly during atmospheric storage at 25 °C for 12 h of incubation and then rapidly decreased. Additionally, the amount of liberated 1-napthol was significantly lower during hypobaric and hypoxic storage at 25 °C. No significant difference in lipase activity was observed between atmospheric and hypobaric conditions, although 1-napthol was liberated at a lower storage temperature of 10 °C. The amylase activity of koji on starch showed a similar tendency to that of protease in different storage conditions (Fig. 7). A gradual increasing pattern of releasing reduced sugars was observed at atmospheric storage until 48 h of incubation at 25 °C. Hypobaric and hypoxic storage at 25 °C significantly suppressed amylase activity. No significant difference in amylase activity was observed between hypobaric and hypoxic storage. Sozzi, Trinchero, and Fraschina (1999) also reported that low oxygen storage of fruits retarded the activity of carbohydrate cleaving/hydrolyzing enzymes. However, lowtemperature storage significantly suppressed amylase activity relative to the other high-temperature storage conditions. Thus, in vitro enzyme assays at different storage conditions clearly indicated that HT-Hypobaric storage has potential utility in suppressing the activities of several enzymes, including protease, lipase, and amylase. This suppression of enzyme activities was probably due to the low concentration of residual oxygen rather than the hypobaric
Lipase activity (eqv. 1-naphthol micromol/g)
Meaty
4
3
HT-Atm HT-Hypobaric HT-Atm-Hypoxic LT-Atm LT-Hypobaric
d d c,d
2
c
b,c
c b
b,c
1 a,b
a,b a,b
a,b
a,b
b
b a,b
a
0
0
a
a
20
40
60
Incubation period (hours)
Koji fermentation period (day) Fig. 4. Development of protease, amylase and lipase enzyme activity during koji fermentation period. Different symbols indicate statistical differences (p b 0.05).
Fig. 6. In vitro enzyme activity of lipase extracted from koji at different storage conditions. Comparisons were among the different treatments at the certain incubation time. Different letters indicate statistical differences (p b 0.05).
A. Giri et al. / Food Research International 44 (2011) 739–747
Amylase activity (eqv. glucose micromol/g)
400
HT-Atm HT-Hypobaric HT-Atm-Hypoxic LT-Atm LT-Hypobaric
300
References
e
e
d,e
d,e d,e
d
200
c,d
c,d
c,d
c
c
c b,c
b,c
100
b
b b
a
0
0
b
b
b
b,c b b
b
a
20
747
40
60
Incubation period (hours) Fig. 7. In vitro enzyme activity of amylase extracted from koji at different storage conditions. Comparisons were among the different treatments at the certain incubation time. Different letters indicate statistical differences (p b 0.05).
stress. While considering low-temperature storage, it was not beneficial to adopt a hypobaric technique, as the low storage temperature played a major role in suppressing enzyme activity. The formation of several volatiles in miso-type products are greatly influenced by enzyme activity on several substrates, including amino acids, sugars, and lipids. Therefore, it can be assumed that hypobaric storage of mature squid miso at room temperature can prolong the shelf-life to maintain aroma attributes. 4. Conclusions 2-Methyl propanal, 3-methyl butanal, 3-methyl-1-butanol, n-ethyl decanoate, 2,3-butanedione, dimethyl disulfide, methional, and 2methyl butanoic acid were identified as key aroma compounds in squid miso on the basis of the OAVs. Low-temperature and lowpressure storage retarded volatile formation and extended the valuable shelf life. Hypobaric storage showed a considerable reduction in the amount of oxidation products, particularly aldehydes and ketones. The amount of sulfur-containing compounds and acids were also significantly lower. Ester production was higher in hypobaric conditions. Production of furans and their analogues was controlled under hypobaric storage. This study demonstrated that hypobaric storage could be considered as an effective preservation means of fish miso to prolong shelf-life in order to maintain aroma attributes even at room temperature.
Belitz, H. D., & Grosch, W. (1987). Food chemistry (1st ed). Heidelberg: Springer Verlag. Berna, A. Z., Geysen, S., Li, S., Verlinden, B. E., Larnmertyn, J., & Nicolai, B. A. (2007). Headspace fingerprint mass spectrometry to characterize strawberry aroma at super-atmospheric oxygen conditions. Postharvest Biology and Technology, 46, 230−236. British Standard Institution Assessors for Sensory Analysis (1993). Guide to selection, training and monitoring of selected assessors. B817667. London, United Kingdom: British Standard Institute. Burg, S. P. (1967). Method for storing fruit. U.S. Pat. 3, 333, 967. Dwivedi, B. K. (1975). Meat flavor. CRC Critical Reviews in Food Technology, 5, 487−535. Fox, P. F., & Wallace, J. M. (1997). Formation of flavour compounds. Advances in Applied Microbiology, 45, 17−85. Giri, A., Osako, K., & Ohshima, T. (2009a). Effect of raw materials on the extractive components and taste aspects of fermented fish paste — Sakana miso. Fisheries Science, 75, 785−796. Giri, A., Osako, K., & Ohshima, T. (2009b). Extractive components and taste aspects of fermented fish pastes and bean pastes prepared using different koji molds as starters. Fisheries Science, 75, 481−489. Giri, A., Osako, K., & Ohshima, T. (2010). Identification and characterization of headspace volatiles of fish miso, a Japanese fish meat based fermented paste, with special emphasis on effect of fish species and meat washing. Food Chemistry, 120, 621−631. Giri, A., Osako, K., Okamoto, A., & Ohshima, T. (2010). Olfactometric characterization of aroma active compounds in fermented fish paste in comparison with fish sauce, fermented soy paste and sauce products. Food Research International, 43, 1027−1040. Herbert, R. A., & Shewan, J. M. (1976). Roles played by bacterial and autolytic enzymes in the production of volatile sulphides in spoiling North Sea cod (Gadus morhua). Journal of the Science of Food and Agriculture, 27, 89−94. Landaud, S., Helinck, S., & Bonnarme, P. (2008). Formation of volatile sulfur compounds and metabolism of methionine and other sulfur compounds in fermented food. Applied Microbiology and Biotechnology, 77, 1191−1205. Marilley, L., & Casey, M. G. (2004). Flavours of cheese products: Metabolic pathways, analytical tools and identification of producing strains. International Journal of Food Microbiology, 90, 139−159. Olivares, A., Navarro, J. L., & Flores, M. (2009). Distribution of volatile compounds in lean and subcutaneous fat tissues during processing of dry fermented sausages. Food Research International, 42, 1303−1308. Pesis, E. (1994). Enhancement of fruit aroma and quality by acetaldehyde or anaerobic treatments before storage. Ada Horticulturae, 368, 365−373. Pesis, E., & Avissar, I. (1989). The post-harvest quality of orange fruits as affected by prestorage treatments with acetaldehyde vapour or anaerobic conditions. Journal of Horticultural Science, 64, 107−113. Sanz, C., Olias, J. M., & Perez, A. G. (1997). Aroma biochemistry of fruits and vegetables. In F. A. Tomas-Barberan, & R. J. Robins (Eds.), Phytochemistry of fruit and vegetables (pp. 125−155). Oxford, UK: Clarendon Press. Sozzi, G. O., Trinchero, G. D., & Fraschina, A. A. (1999). Controlled-atmosphere storage of tomato fruit: Low oxygen or elevated carbon dioxide levels alter galactosidase activity and inhibit exogenous ethylene action. Journal of the Science of Food and Agriculture, 79, 1065−1070. Thomas, C. P., Dimick, D. S., & McNeil, J. H. (1971). Sources of flavor in poultry skin. Food Technology, 25, 109−115. Whistler, R. L., & Daniel, J. R. (1985). Carbohydrates. In O. Fennema (Ed.), Food chemistry (pp. 69−137). New York, NY: Marcel Dekker Inc.