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Qualitative effects of fresh and dried plum ingredients on vacuum-packaged, sliced hams
Meat Science 83 (2009) 74–81
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Qualitative effects of fresh and dried plum ingredients on vacuum-packaged, sliced hams M.T. Nuñez de Gonzalez a, B.S. Hafley b, R.M. Boleman c, R.M. Miller d, K.S. Rhee d, J.T. Keeton e,* a
Department of Food Technology, Universidad de Oriente, Núcleo Nueva Esparta, Escuela de Ciencias Aplicadas del Mar, Isla de Margarita 6301, Venezuela Tyson Foods, 1825 Ford Ave., Springdale, AR 72764, United States c Byan Independent School District, 1920 N. Earl Rudder Freeway, Bryan, TX 77808, United States d Department of Animal Science, Texas A&M University, 338 Kleberg Center, College Station, TX 77843-2471, United States e Department of Nutrition and Food Science, Texas A&M University, 122 Kleberg Center, College Station, TX 77843-2253, United States b
a r t i c l e
i n f o
Article history: Received 12 August 2008 Received in revised form 27 February 2009 Accepted 3 April 2009
Keywords: Plum juice concentrates Ham Color Lipid oxidation
a b s t r a c t Boneless ham muscles (Semimembranosus + Adductor) were injected (20% w/w) with a curing brine containing no plum ingredient (control), fresh plum juice concentrate (FP), dried plum juice concentrate (DP), or spray dried plum powder (PP) at 2.5% or 5%. Hams were cooked, vacuum-packaged, stored at <4 °C and evaluated at 2-week intervals over 10 week. Evaluations were performed on sliced product to determine cook loss, vacuum-package purge, Allo–Kramer shear force, 2-thiobarbituric acid-reactive substances (TBARS), proximate analysis, objective color, sensory panel color and sensory attributes. FP, DP and 2.5% PP increased (P < 0.05) cook loss by 2% to 7% depending on treatment and level, but the highest cook loss (17.7%) was observed in hams with 5% PP. Shear force values increased as the level of plum ingredient increased (P < 0.05) from 2.5% to 5%, and the highest shear values were observed in hams containing 5% FP. There were no differences (P > 0.05) in lipid oxidation among treatments as determined by TBARS and sensory evaluation. FP and PP ham color was similar to the control, but DP had a more intense atypical color of cured ham. Minimal changes in physical, chemical and sensory properties were observed during storage of all treatments. Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction Dried plum puree contains indigenous chemical compounds that serve specific functions in foods: pectin aids in moisture retention, while malic acid enhances flavor, and sorbitol acts as a natural humectant. Phenolic compounds present in dried plum puree have been reported to be the main contributors of its antioxidant properties (Donovan, Meyer, & Waterhouse, 1998; Fang, Yu, & Prior, 2002; Kreuzer, 2001; Wang, Cao, & Prior, 1996). Because of its potential benefits, dried plum puree has been approved by USDA for use in ground beef destined for the US school lunch program. Hamburgers containing 3–5% dried plum puree have been shown to retain more moisture (after cooking) and were rated by students to be equal or better than hamburger products from major fast food chains (Decker, 1999). Moisture retention in that study was improved 15.8% in precooked patties reheated to
* Corresponding author. Tel.: +1 979 845 3975; fax: +1 979 862 6842. E-mail address: [email protected] (J.T. Keeton). 0309-1740/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2009.04.002
102 °C and held in warming trays for up to 4 h. Leheska et al. (2006) found that the addition of dried plum puree to precooked pork breakfast sausage can increase phenolics that may be nutritionally beneficial while also having consumer appeal. Nuñez de Gonzalez, Boleman, Miller, Keeton, and Rhee (2008a) indicated that the inclusion of 3% dried plum puree (DP) or 3% or 6% dried plum and apple puree (DPA) increased moisture and decreased fat content of raw and precooked pork sausages. Moreover, they found that DP used at 3% or 6% levels was as effective as a combination BHA/BHT (0.02%) for retarding lipid oxidation. Similarly, Lee and Ahn (2005) found that the addition of 2% plum extract or higher was effective at retarding lipid oxidation while enhancing juiciness in irradiated turkey breast rolls. Previous research with plum juice concentrates in roast beef (Nuñez de Gonzalez et al., 2008b) has shown a retention and enhancement of red color during refrigerated storage, a reduction in lipid oxidation and no detrimental effects on sensory attributes of precooked roast beef. Thus, the objective of this study was to determine if the inclusion of different levels of plum juice concentrates could improve quality, retain cured color during refrigerated storage and retard lipid oxidation in sliced vacuum-packaged, brine-injected hams.
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2. Materials and methods
2.2. Determination of cook loss
2.1. Ham processing
Chilled hams were weighed prior to opening the cook-in bags to obtain cooked, packaged weights. Individual hams were then removed from the package, drained thoroughly, and the cooked meat weights and empty package weights were recorded to calculate total cook loss as follows:
Fresh, chilled, trimmed, boneless, inside ham muscles (Semimembranosus + Adductor), USDA-IMPS # 402, weighing 0.9 to 1.8 kg were acquired from Tyson Foods Inc. (3–4 days postmortem), Houston, Texas. Inside ham muscles had been previously trimmed of fat and membranes and were ready for injection upon arrival. Hams were prepared in a state inspected (Texas Department of Health), commercial-scale pilot plant located in the Rosenthal Meat Science and Technology Center at Texas A&M University. A total of 168 hams (Table 1) or 24 hams per treatment were randomized and injected (Inject Star, Model BI-72, Brookfield, CT) with a brine solution (20% by weight of raw product) containing (1) no plum ingredient (control), (2) 2.5% or 5% fresh plum juice concentrate (FP), (3) 2.5% or 5% dried plum juice concentrate (DP), (4) 2.5% or 5% spray dried plum powder (PP) rehydrated in the curing brine. All plum ingredients used in this study were obtained through the California Dried Plum Board from Sunsweet Growers Inc., Yuba City, CA. The other ingredients, as percent after injection into the product and thermal processing, included food grade salt (2.5%, Salt Culinox 999 food grade, Morton International Inc., Chicago IL), dextrose (0.9%, Newly WedsÒ Foods, Bedford Park, IL), alkaline phosphate (0.35%, BifisolÒ512, BK Giulini Co, Simi Valley, CA), potassium lactate (3%, Purasal P HiPure 60, Purac America Inc., Lincolnshire, IL), sodium nitrite (0.19%, Heller’s modern cure, Heller Seasoning and Ingredients Inc., Chicago, IL), sodium erythorbate (0.49%, FCC Heller Seasoning and Ingredients Inc., Chicago, IL), and water. After brine injection, the hams were allowed to drain to remove excess brine and then re-weighed, and pumped weights were recorded to determine the percent pump. The hams were vacuum tumbled (Model VT500, Leland Southwest Inc., Ft. Worth, TX; 846.6 mbar, 4–5 rpm) in a room maintained at 65 °C for 1 h to aid brine ingredient distribution and absorption. Following tumbling, product weights were recorded. Then, hams were vacuumpackaged in CryovacÒ cook-in bags (type CN530, product # 97725, 30.48 cm by 60.96 cm, Cryovac North America, Duncan, SC) and re-weighed, and packaged weights were recorded. Prior to cooking, hams were stored overnight in a cooler maintained at <4 °C to allow for brine equalization. The hams were cooked using an incremental cook cycle in a steam-heated smokehouse (Model 1000, Alkar, DEC International Inc., Lodi, WI) to achieve a product endpoint temperature of 71.1 °C. The smokehouse was set for the following conditions: 1 h 60 °C, 2 h at 68.3 °C, 1 h at 76.7 °C and 2–4 h at 85 °C. After cooking, the hams were cooled to 37.7 °C by showering with cold water for 6 to 8 min. Finally, the products were cooled according to USDA-FSIS (1999, Appendix B) guidelines and stored in cardboard boxes 2–3 d in the dark at <4 °C. Table 1 Experimental design of ham allocations by treatment and storage time. Treatmenta
Control FP 2.5% FP 5% DP 2.5% DP 5% PP 2.5% PP 5%
Storage time (week)
Total
0
2
4
6
8
10
4 4 4 4 4 4 4
4 4 4 4 4 4 4
4 4 4 4 4 4 4
4 4 4 4 4 4 4
4 4 4 4 4 4 4
4 4 4 4 4 4 4 Total
24 24 24 24 24 24 24 168
a Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder.
Cook lossð%Þ ¼ ½raw weight cooked weight=raw weight 100 After determining cook loss, hams assigned to storage treatments (2, 4, 6, 8, and 10 week) were vacuum-packaged (UltravacÒ 2100, vacuum setting 7 and seal setting 7, KOCH Inc., Kansas City, MO) in CryovacÒ bags (type BH620T, product # 9D640, 33.02 cm by 66.04 cm, Cryovac North America, Duncan, SC) and stored in a cooler maintained at <4 °C for their respective storage period. At the end of each designated storage period, hams from each treatment were split in half, sliced and evaluated for vacuum-package purge, Allo–Kramer shear force, descriptive attribute sensory panel evaluation, color space values (L*, a*, b*), lipid oxidation, and proximate analysis. An additional set of sliced samples were stored 21 d to evaluate vacuum purge at the end of the 21 d period (Fig. 1). All sample slices were vacuum-packaged in CryovacÒ bags (type B540, product # 90184, 17.78 cm by 30.48 cm, Cryovac North America, Duncan, SC) and stored at <4 °C until analyses could be performed the following day. 2.3. Sliced vacuum-package purge at 21-d post ham storage At the end of each designated storage period (0, 2, 4, 6, 8, 10 week), a 454 g sample consisting of 0.31-cm thick slices from each ham was vacuum-packaged and stored in the dark for an additional 21 d at <4 °C. After 3 week, ham slices from each treatment were weighed to obtain a total package weight. Slices were then removed from the package, patted dry with a towel to remove excess moisture, and reweighed. Purge was calculated as total package weight minus package and sample weights. Percent vacuumpackage purge was determined using the following formula:
Vacuum package purgeð%Þ ¼ ½ham weight with purge ham weight without purge= ham weight with purge 100 2.4. Color determination L*, a*, b* color space values for the ham treatments at each designated storage time were recorded using a Minolta Colorimeter (Model CR-300, Minolta Corp., Ramsey, NJ)), with an 8-mm viewing port and illuminant D65. The instrument was calibrated with a white standard tile (L* = 97.55, a* = -0.02, b* = 1.56 set to channel 00). Color measurements were made on each slice per treatment by dividing the slice into three imaginary triangular sections imitating from the center of the slice and randomly taking a measurement within each section. The results were expressed as positive L* (lightness), a* (redness) and b* (yellowness) color space values. 2.5. Measurement of lipid oxidation Lipid oxidation of each treatment at each designated storage time was determined by 2-thiobarbituric acid-reactive substances (TBARS) procedure of Tarladgis, Watts, Younathan, and Dugan (1960) as modified by Rhee (1978). Each sample was analyzed in duplicate and results were expressed as mg of malonaldehyde (MDA) per kg of meat.
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Raw Hams (n = 24 per treatment/storage combination) Treatments: -Control -2.5% FP - 5% FP -2.5 % DP - 5% DP -2.5% PP -5% PP
Injection (20%)/Cooking/Chilling Cook loss determination Packaging (whole pieces)
Store (whole pieces) at 4°C for 10 wk
Slice whole pieces at each test week (0, 2, 4, 6, 8 and 10) for physicochemical and sensory analyses
Sliced 0.7 cm: -Allo-Kramer shear force -Sensory evaluation -Proximate analysis
Sliced 0.48 cm: -Vacuum-package purge -Color evaluations (L*, a*, b*) -Lipid oxidation (TBARS)
Sliced 0.31 cm: -Vacuum-package purge at 21 d poststorage
Fig. 1. Flow chart of ham processing, and physicochemical and sensory analyses.
2.6. Allo–Kramer shear force determination Allo–Kramer shear force measurements were performed on each treatment at the end of each designated storage period using an Instron Universal Testing Machine (Model 1011, Instron Corporation, Houston, TX). A standardized specimen size (2 by 5 cm2) was cut, weighed and placed flat in a 10-blade Allo–Kramer shear cell attached to a 500 kg load cell with a standard load range setting of 100 kg. Kilograms of shear force were recorded and divided by the sample weight to determine the shear force in kg/g of sample. This value was then converted to Newtons/g by multiplying kg 9.8. 2.7. Proximate analysis Percentages of moisture (AOAC, 2000, method 950.46), fat (AOAC, 2000, method 985.15), and protein (AOAC, 2000, method 992.15) were determined on finished products. Slices from hams assigned to each treatment at the 0 week storage period were homogenized in a food processor (Model R6, Robot Coupe S.A., Bagnolet, France) before sampling. Moisture and fat content (%) were determined using a convection air-dry oven and Soxhlet ether extraction methods, respectively. Crude protein percentage was determined by the Dumas combustion method to release gaseous N2 (Leco FP-528 Protein Analyzer, St. Joseph, MO). The procedure was standardized using oatmeal (Part No 502–276, %N = 9.56 ± 0.04). Percent crude protein was calculated as 6.25 times the percent nitrogen. All analyses of the samples were performed in duplicate. 2.8. Sensory evaluation Descriptive attribute analysis was performed on hams samples for each treatment and evaluated by a 7-member trained expert descriptive attribute sensory panel in the Texas A&M University
Sensory Testing Facility. Panelists were trained according to the procedures of Cross, Moen, and Stanfield (1978), AMSA (1995) and Meilgaard, Civille, and Carr (1999), and had more than five years of experience in SpectrumTM descriptive flavor and texture analysis (Meilgaard et al., 1999). The panel underwent an orientation session using hams prepared without antioxidant (control ‘‘as is”) and with antioxidant treatments (2.5% or 5% FP, 2.5% or 5% DP and 2.5% or 5% PP). Panel-specific training was conducted for 6 d. Panelists underwent performance evaluation as specified in the guidelines developed by AMSA (1995) prior to initiation of the study to assure that panelists were sufficiently trained. Samples were evaluated for aromatics (cooked pork, cured lean, cured fat, chemical taste, canned meat, and fresh/dried plum); basic tastes (salt, sour, bitter and sweet); feeling factors (astringent, metallic, and chemical burn) and texture attributes (springiness, juiciness, hardness, cohesiveness, and denseness). All samples were scored using the 0–15 Spectrum Universal intensity scale (Meilgaard et al., 1999) where 0 = absence of an attribute and 15 = extremely intense. In addition, panelists evaluated texture (springiness, juiciness, hardness, cohesiveness and denseness) using the 0–15 Spectrum Universal Intensity scale (Meilgaard et al., 1999) where 0 = not springy, dry, soft, crumbles, airy and 15 = very springy, juicy, hard, defined particle size, dense for each attribute. Reference standards for the sensory attributes that were used for the evaluation of ham are shown in Table 2. Ham samples from each treatment were evaluated at 2 week intervals. On each testing day, 7 samples were evaluated per day during one session. The order of the treatments was randomized and a warm-up was presented to judges before sample evaluation to ensure that they were familiar with the treatment attributes to be tested. The stimuli used for warm-up were hams from a control formulation. The ham samples were labeled with random 3-digit numbers and placed in clear 6-oz samples cups with lids. Panelists received two randomly selected samples (2.54 cm squares) from each ham that was maintained at 4–6 °C. Testing was conducted
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Table 2 Reference standards for sensory attributes and their intensities based on 0–15 Spectrum Universal intensity scale (0 = absent, 15 = extremely intense) established after consensus discussions with the expert panel. Sensory attribute
Reference standard
Scale value
Aromatics Cooked pork Cured lean Cured fat Chemical taste Canned meat Fresh/dried plum
Concentrated pork broth Ham (Oscar Mayer, Kraft Foods Global, Inc., Northfield, IL, USA) Beef hot dog (Oscar Mayer, Kraft Foods Global, Inc., Northfield, IL, USA) Cherry juice with 500 ppm bleach added (odor only) Canned chicken (SwansonÒ, Campbell Soup Co., Camden, NJ, USA) Prunes placed in mouth
15 12 5.5 15 15 15
Feeling factors Astringent Metallic Chemical burn
Cooked sample of liver, 1.27 cm Black tea (LiptonÓ, Englewood Cliffs, NJ, USA) bag placed in hot water and steeped for 1 h White vinegar (H.J. Heinz Co., Pittsburg, PA, USA)
15 6.5 15
Basic tastes Salt Sour Bitter Sweet
Potato chips (Pringles, Procter & Gamble, Cincinnati, OH, USA) Lemon juice (Real LemonÒ, Mott’s Inc., Stanford, CT,USA) Caffeine (0.15% solution) Chocolate bar (The Hershey Co., PA, USA)
13 8.0 10.0 10.0
Textures Springiness Juiciness Hardness Cohesiveness Denseness
Marshmallow (miniature, Wal-Mart Inc., Bentonville, AR, USA) Apple (Red Delicious variety) Hard candy (Life SaversÒ, WM. Wrigley JR. Co., Chicago, IL, USA) Candy chews (Starburst, Master-foods USATM, Hackettstown, NJ, USA) Malted milk balls (Whopper, The Hershey Co., PA, USA)
9.5 10.0 14.5 12.5 6.0
in isolated booths fitted with a breadbox server and red incandescent lighting to mask color differences. Unsalted crackers, ricotta cheese and distilled water were available to judges to clear their palate of residual flavors between samples. The trained panelists also evaluated ham samples for subjective color. Slices from each treatment were selected at random and displayed for evaluation of color intensity, greyness, off-color, and iridescence. Panelists scored ham slices for overall color using an 8point descriptive scale (1 = grey; 8 = dark reddish pink). Using a 6-point descriptive scale panelists also scored percent surface discoloration (grey and/or brown) (1 = no/0% surface grey color, no/0% surface brown color; 6 = total/100% surface grey color, total/100% surface brown color and iridescence (1 = none, 0%; 6 = very strong, 100%). All samples were evaluated subjectively under standard room fluorescent lighting (Econ-o-watt F40CW/RS/EW, 34 W, Philips Electronics North America, New York, NY). After color evaluation by the sensory panel, L* (lightness), a* (redness), and b* (yellowness) color space values were determined on the same ham slices using a Minolta colorimeter (Model CR300, Minolta Corporation, New Jersey). 2.9. Experimental design and statistical analysis The experiment was designed as a complete randomized factorial design (7 ingredient treatments 6 storage times). Ingredient treatments included a control (no antioxidant), 2.5% and 5% FP, 2.5% and 5% DP, and 2.5% and 5% PP. Twenty-four hams were randomly assigned to the treatment and storage combinations (Table 1). Hams were cooked and then stored at <4 °C for 0, 2, 4, 6, 8 and 10 weeks. At 2-week intervals, samples were assessed for vacuumpackage purge, Allo–Kramer shear force, TBARS, color space values, sensory attributes and sensory color for 10 weeks. Proximate analysis was performed on finished products from each ingredient treatment. Due to cost constraints, the entire experiment was performed one time with 4 hams allocated to each treatment (7) and storage (6) combination (Table 1). Thus, a total of 24 experiment units were assigned to each treatment within a 10-week storage period. Data were analyzed as a 7 6 factorial design using the General Linear Model (GLM) procedure of the Statistical Analysis System
(SAS, 1995). The main effects for the model were level of ingredients (FP, DP and DP) at 0%, 2.5% or 5% of the cooked weight and storage time (0, 2, 4, 6, 8, or 10 weeks). Analysis of variance was used to determine statistical differences among the main effects and their interactions with a significant level of P < 0.05. Least squares means were used to identify significant treatment effects. Sensory evaluation data were pooled across panelists and were analyzed as previously described.
3. Results and discussion 3.1. Effect of fresh and dried plum ingredients on physical and chemical properties of precooked ham The injection of fresh and dried plum ingredients into boneless, cured ham muscles affected percent cook loss, objective color, and Allo–kramer shear value (Table 3). Incorporation of plum juice concentrates or spray dried powder into precooked cured hams increased cook loss by 2–7%, depending on treatments and levels. FP tended to increase percent cook loss with increasing level of plum ingredient while notable increases (P < 0.05) were observed as DP and PP levels increased from 2.5% to 5%. The highest cook loss (17.7%) was observed in hams containing 5% PP. O’Neill, Lynch, Troy, Buckley and Kerry (2003) reported a similar cook loss percentage of 16.9% in normal cooked hams. Even with changes in percent cook loss, the addition of various fresh and dried plum ingredients had no effect on vacuum-package purge or sliced vacuum-package purge 21 days post storage. The addition of FP or PP (2.5% or 5%) did not affect objective L* (lightness) color space values. However, incorporation of DP, which has a slightly darker in color than FP and PP, lowered (P < 0.05) L* values (i.e., darkened ham slice color slightly). Redness (a*) values were higher for all plum treatments as compared to the control and were incrementally higher with 5% DP or PP than the 2.5% levels of the respective ingredients. Hams injected with DP had the highest (P < 0.05) a* (redness) color space values, but the color was not typical of the traditional reddish pink color of cured pork as noted by a* values of the treatments. Hams containing FP or PP were redder (P < 0.05) than control hams by only 1–2 a* units, but these differ-
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Table 3 Least squares means for percent cook loss, vacuum-package purge, sliced vacuum-package purge at 21-d post storage, L* a* b* color space values, TBARS values, and Allo–Kramer shear force values of cured, boneless ham with fresh/dried plum ingredients. Treatmentf
Cook loss (%)
Vacuum-package purge (%)
Sliced vacuum-package purge at 21-d post storage (%)
Color space values L* a* b*
Control FP 2.5% FP 5% DP 2.5% DP 5% PP 2.5% PP 5% SEMg
10.6a 12.6b 13.7bc 13.0b 14.8c 12.9b 17.7d 0.6
2.8 2.5 2.4 2.8 2.5 2.7 2.5 0.2
2.8 2.7 2.9 3.2 3.0 2.7 2.7 0.2
61.9cd 61.6cd 60.1abc 59.8ab 58.5a 61.4bc 63.4d 0.6
a–e f g
12.4 13.0 12.7 11.9 12.7 12.3 12.6 0.3
Allo–Kramer shear force value (Newtons/g sample)
0.12 0.14 0.11 0.11 0.12 0.12 0.14 0.1
44.1ab 42.1a 51.9c 47.0b 51.0c 46.1b 51.0c 1.1
Least squares means in the same column without a common superscript letter differ (P < 0.05). Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder. SEM = Standard error of the mean.
ences were small and may not be perceived by the human eye. Yellowness, as measured by b* color space value, was unaffected (P > 0.05) by the incorporation of the plum ingredients. Lee and Ahn (2005) reported that the addition of plum extract puree (PEP) increased a* and b* values and decreased L* value of turkey breast rolls due to the darker color of plum extract. Also, these researchers indicated that the color of turkey rolls with 3% PEP was dark and might not be appealing to consumers. Thus, these results may indicate potential difficulties with consumer acceptance of the off-red color produced with the injection of DP, while FP may yield a more acceptable color. TBARS values of hams injected with plum ingredients at 2.5% or 5% were similar (P > 0.05) to that of the control. The presence of sodium nitrite, sodium erythorbate and alkaline phosphates in ham enhances pigment stabilization, inhibits lipid and pigment oxidation, and thus would be expected to contribute some antioxidant properties in comparison to uncured products. Unlike the antioxidant effect of plum concentrates in precooked pork sausage (Nuñez de Gonzalez et al., 2008a) and roast beef (Nuñez de Gonzalez et al., 2008b), hams were not as susceptible to lipid oxidation due to inclusion of sodium nitrite and alkaline phosphates. Allo–Kramer shear force values of ham samples increased as the level of plum ingredient increased (P < 0.05) from 2.5% to 5%. The higher loss of moisture during cooking for the 5% level likely caused the increase in Allo–Kramer shear force values that indicate a slight reduction in tenderness. Results for percent moisture, fat, and protein values are presented in Table 4. Ham samples containing 5% DP and PP were lower (P < 0.05) in moisture content, while samples containing 2.5% DP were slightly higher (P < 0.05) when compared to the control. Since the percent cook loss was significantly higher (P < 0.05) for the 5%
Table 4 Least squares means for percent moisture, fat, and protein of cured, boneless ham with fresh/dried plum ingredients. Treatmentg Control FP 2.5% FP 5% DP 2.5% DP 5% PP 2.5% PP 5% SEMh a–f
4.7a 7.0c 7.3c 10.2d 11.2e 5.8b 7.0c 0.4
TBARS (mg MDA/kg)
Moisture (%) c
70.3 70.6cd 70.3c 70.8d 68.2a 69.8b 68.2a 0.1
Fat (%) d
2.3 2.6e 0.8a 1.0b 1.5c 1.1b 3.0f 0.1
Protein (%) 23.8b 22.8a 24.7d 24.2c 25.4e 24.0bc 25.4e 0.1
Least squares means in the same column without a common superscript letter differ (P < 0.05). g Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder. h SEM = Standard error of the mean.
DP and PP samples, lower percentages of moisture would be expected. With lower percentages of moisture, percent fat would normally be expected to be higher; however, percent fat was variable which is possibly due to the retention of plum solids during cooking. Different levels of solids retention also would cause variations in the individual components of the proximate analysis. For example, hams injected with FP at 5% and DP at 2.5% or 5% had higher (P < 0.05) levels of protein as compared to the control, but hams with 2.5% FP had a lower level of protein. Changes in percent fat and percent protein were small and likely varied in response to cooking loses and retained solids. In contrast to the results of the present study, Lee and Ahn (2005) reported that the composition, especially moisture and lipid contents, of RTE (Ready-to-eat) turkey breast rolls with plum extract puree-added (1%, 2% and 3%) were similar to that of control. 3.2. Storage effects on physical and chemical properties of precooked ham Table 5 summarizes cook loss, vacuum-package purge, sliced vacuum-package purge at 21-d post storage, objective color, TBARS, and Allo–kramer shear values during storage of refrigerated vacuum-packaged hams with plum ingredients. No differences (P > 0.05) were noted in cook loss for whole hams over a 10-week storage period, but percent vacuum-package purge increased as storage progressed. After 21-d post storage, vacuum-package purge of ham slices was not different except at week 6. Objective color values during refrigerated vacuum-package storage did change slightly, but not more than 1–2 units from the control. L* (lightness) color space values increased slightly (P < 0.05) after 6 and 10 weeks of refrigerated storage, while a* (redness) and b* (yellowness) values decreased slightly (P < 0.05) at week 4 and 10. TBARS values fluctuated slightly (up and down) over the 10-week period of refrigerated vacuum-package storage, but tended to increase after 6 week. However, there were no clear patterns observed in TBARS values due to storage. Little to no changes was observed for Allo–Kramer shear force values except at week 10 when ham samples became slightly (P < 0.05) less tender. 3.3. Sensory properties of sliced ham with fresh and dried plum ingredients In general, most fresh/dried plum aromatics, with the exception of cured lean, were just above the threshold for detection in samples with plum ingredients. With the exception of FP 2.5% and PP 2.5%, which were not different from the control, only the fresh/ dried plum aromatic increased (P < 0.05) in treatments with the addition of plum ingredients (Table 6). The fresh/dried plum
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Table 5 Least squares means for percent cook loss, vacuum-package purge, sliced vacuum-package purge at 21-d post storage, L* a* b* color space values, TBARS values, and Allo–Kramer shear force values of cured, boneless ham stored under refrigerated conditions. Storage week
Cook loss (%)
Vacuum-package Purge (%)
Sliced vacuum-package purge at 21-d post storage (%)
Color space values L*
a*
b*
0 2 4 6 8 10 SEMg
14.3 13.3 13.1 13.6 13.6 13.9 0.6
NTf 2.1a 2.5ab 2.8bc 2.7bc 2.9c 0.13
2.9bc 3.3c 3.1c 2.3a 3.2bc 2.4ab 0.2
60.3ab 61.6bc 58.8a 62.9c 60.2ab 62.0c 0.6
8.0b 7.9b 6.8a 7.9b 8.2b 6.7a 0.3
13.1c 13.1c 12.1b 13.1c 13.1c 10.7a 0.2
a–e f g
TBARS (mg MDA/kg)
Allo–Kramer shear force value (Newtons/g sample)
0.11bc 0.02a 0.08b 0.17d 0.13c 0.23e 0.2
48.0bc 46.1ab 44.1a 46.1ab 49.0cd 51.9d 1.1
Least squares means in the same column without a common superscript letter differ (P < 0.05). NT, not tested. SEM = Standard error of the mean.
aromatic intensity was greatest in hams injected with 5% DP. Salt was the dominant taste, but it was less (P < 0.05) in hams with 5% plum ingredient. Sensory scores for sour taste of hams injected with plum material were not different from the control except that 5% PP was deemed slightly (P < 0.05) less sour. Similar to the plum aromatic, sweet taste increased (P < 0.05) in hams with a 5% level of ingredient likely due to the higher levels of sugars in the juice or powder concentrates. No textural differences in hams were noted due to plum ingredients. Likewise in a study performed by Katsaras and Budras (1993), the textural attributes of cohesiveness and juiciness of high quality hams were not affected by the addition of plum ingredients. Overall, the inclusion of 5% plum ingredients increased the fresh/dried plum aromatic note and sweetness taste slightly, but decreased saltiness. As a consequence, only a few sensory attributes of ham were affected by the inclusion of plum ingredients and these only minimally. The addition of plum ingredients to ham was found to affect subjective color, off-color, and iridescence scores (Table 7). Compared to control hams, subjective color intensity scores were similar (P > 0.05) across plum treatments and levels with the exception
of hams containing 2.5% PP which were slightly more reddish pink (P < 0.05). Subjective color scores indicated that DP 2.5% and PP 5% tended to be more grey than the other plum treatments, but were not different from the control. In comparison, a* values (Table 3) indicated DP treatments to be redder, but these samples had slightly higher (P < 0.05) off-color (brown) scores in comparison to all other samples, regardless of level. Increasing the level of DP from 2.5% to 5% also increased (P < 0.05) scores for brown off-color due to the inherently darker pigments in DP. Iridescence scores were low overall, but ham samples containing 2.5% FP, 2.5% DP, and 5% PP had slightly more (P < 0.05) iridescence present than the control. Overall, some variations in color (redness) intensity of hams treated with fresh/dried plum ingredients were noted, but only PP 2.5% was of sufficient magnitude to be different from the control. Off-color was most notable for the DP treatment and some slight increase in iridescence was observed with low levels of FP and DP and a high level of PP. The observed changes in color indicate that the addition of DP to cured boneless hams may detrimentally affect product appearance, but that FP and PP would have a limited effect on appearance.
Table 6 Least squares means of descriptive attribute sensory panel scores for aromaticse, feeling factorse, basic tastese, and texturesf of cured, boneless ham with fresh/dried plum ingredients. Treatmentsg SEMh Control
FP 2.5%
FP 5%
DP 2.5%
DP 5%
PP 2.5%
PP 5%
Aromatics Cooked pork Cured lean Cured fat Chemical taste Canned meat Fresh/dried plum
1.3 6.9 1.7 0.2 0.7 0.0a
1.2 6.9 1.6 0.3 0.6 0.5ab
1.3 6.3 1.5 0.2 0.6 0.8b
1.2 6.8 1.6 0.2 0.6 0.8b
1.3 6.3 1.6 0.3 0.4 1.8c
1.3 7.0 1.7 0.3 0.7 0.2a
1.1 6.7 1.4 0.1 0.4 0.9b
0.2 0.2 0.2 0.1 0.1 0.2
Feeling factors Astringent Metallic Chemical burn
2.5 1.9 0.2
2.4 1.8 0.4
2.2 1.8 0.5
2.3 1.8 0.5
2.2 1.7 0.4
2.5 1.8 0.6
2.0 1.5 0.3
0.1 0.1 0.1
Basic taste Salt Sour Bitter Sweet
7.6cd 1.8bcd 1.4 1.4a
7.2cd 1.9cd 1.5 1.5ab
5.9a 1.6ab 1.3 1.8bc
7.1bc 2.1d 1.6 1.5ab
6.4ab 1.9bcd 1.4 2.0c
7.9d 1.7abc 1.7 1.3a
6.0a 1.5a 1.2 1.9c
0.3 0.1 0.2 0.1
Textures Springiness Juiciness Hardness Cohesiveness Denseness
5.4 4.5 5.2 6.0 6.7
5.5 4.4 5.3 5.7 6.6
5.3 4.4 5.3 6.0 6.5
5.4 4.4 5.1 6.1 6.4
5.3 4.5 5.5 6.1 6.7
5.3 4.6 5.3 6.1 6.7
5.1 4.6 5.1 5.9 6.3
0.2 0.2 0.2 0.2 0.2
a–d e f g h
Least squares means in the same row without a common superscript letter differ (P < 0.05). Based on the 0–15 Spectrum Universal Intensity scale (0 = absence of flavor; 15 = extremely intense flavor). Based on the 0–15 Spectrum Universal Intensity scale (0 = not springy, dry, soft, crumbles, airy; 15 = very springy, juicy, hard, defined particle size, dense). Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder. SEM = Standard error of the mean.
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Table 7 Least squares means of descriptive attribute sensory panel scores for colore, grey colorf, off colorg, and iridescenceh of cured, boneless ham slices with fresh/dried plum ingredients.
Table 9 Least squares means of descriptive attribute sensory panel scores for colore, grey colorf, off colorg, and iridescenceh of cured, boneless ham stored under refrigerated condition.
Treatmenti
Color
Grey color
Off color
Iridescence
Storage week
Color
Grey color
Off color
Iridescence
Control FP 2.5% FP 5% DP 2.5% DP 5% PP 2.5% PP 5% SEMj
4.4abc 4.8cd 4.8cd 4.0a 4.7bcd 5.1d 4.2ab 0.2
1.3 1.1 1.1 1.6 1.4 1.1 1.3 0.2
1.5a 1.5a 1.4a 3.0b 3.9c 1.5a 1.7a 0.2
1.5a 2.1bc 1.4a 2.2bc 1.8ab 1.5a 2.3c 0.2
0 2 4 6 8 10 SEMi
4.5b 4.9b 4.8b 4.8b 4.1a 4.4ab 0.2
1.2b 0.6a 1.2b 1.4bc 1.5bc 1.9c 0.2
2.0 1.7 2.4 2.0 2.3 1.9 0.2
1.6ab 1.3a 2.2cd 1.7bc 2.2cd 1.9bcd 0.2
a–d
a–d
Least squares means in the same column without a common superscript letter differ (P < 0.05). e Based on a 8-point intensity scale (1 = grey; 8 = dark reddish pink). f Based on a 6-point intensity scale (1 = no/0% surface grey color; 6 = total/100% surface grey color). g Based on a 6-point intensity scale (1 = no/0% surface brown color; 6 = total/ 100% surface brown color). h Based on a 6-point intensity scale (1 = none, 0%; 6 = very strong, 100%). i Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder. j SEM = Standard error of the mean.
Table 8 Least squares means of descriptive attribute sensory panel scores for aromaticse, feeling factorse, basic tastese, and texturesf of cured, boneless ham stored under refrigerated conditions. SEMg
Storage week 0
2
4
6
8
Aromatics Cooked pork Cured lean Cured fat Chemical taste Canned meat Fresh/dried plum
4.9b 3.2a 0.7a 0.7c 1.5c 0.4c
0.4a 7.7b 1.2b 0.1ab 0.6b 0.0a
0.3a 7.5b 2.1c 0.2ab 0.2a 0.1b
0.3a 7.6b 1.9c 0.0a 0.1a 0.0a
0.2a 7.4b 1.9c 0.3b 0.3ab 0.0
0.2 0.2 0.1 0.1 0.1 0.2
Feeling factors Astringent Metallic Chemical burn
2.2 1.7 0.5bc
2.1 1.8 0.3ab
2.5 1.8 0.7c
2.2 1.6 0.1a
2.4 1.9 0.4abc
0.1 0.1 0.1
Basic tastes Salt Sour Bitter Sweet
6.5 1.6a 1.3a 1.1a
7.0 1.7ab 1.3a 1.7b
7.1 2.0bc 1.8b 1.7b
6.9 1.6a 1.4a 1.7b
7.0 2.0c 1.4a 1.9b
0.3 0.1 0.2 0.1
Textures Springiness Juiciness Hardness Cohesiveness Denseness
4.6a 4.3a 5.4bc 6.1bc 6.8b
5.5bc 4.2a 5.5c 6.3cd 6.7b
5.0ab 4.9b 5.4bc 6.5d 6.1a
5.6cd 5.1b 5.1ab 5.7b 6.0a
6.0d 4.1a 4.8a 5.3a 7.2b
0.2 0.2 0.2 0.2 0.2
Least squares means in the same column without a common superscript letter differ (P < 0.05). e Based on a 8-point intensity scale (1 = grey; 8 = dark reddish pink). f Based on a 6-point intensity scale (1/0% = no surface grey color; 6 = total/100% surface grey color). g Based on a 6-point intensity scale (1/0% = no surface brown color; 6 = total/ 100% surface brown color). h Based on a 6-point intensity scale (1 = none, 0%; 6 = very strong, 100%). i SEM = Standard error of the mean.
week of storage, chemical taste and canned meat aromatic scores both decreased (P < 0.05) in intensity while cured fat increased slightly (P < 0.05). Salt taste did not change during storage and remained the overall numerically dominant taste throughout storage. Sweet taste increased slightly after week 0 and remained through week 8. Sour taste scores were only slightly higher (P < 0.05) at 4 and 8 week. No consistent pattern was observed in texture scores over the storage period even though slight differences were observed on different test days. It appears that refrigerated storage of vacuum-packaged ham primarily caused a decline in cooked pork aroma and a corresponding increase in cured lean aroma. Evaluation of color intensity and off-color were not different (P > 0.05) due to storage and only a few small changes in grey color and iridescence of ham slices were noted by the sensory panel as a result of storage (Table 9). 4. Conclusion
a–d Least squares means in the same row without a common superscript letter differ (P < 0.05). e Based on the 0–15 Spectrum Universal Intensity scale (0 = absence of flavor; 15 = extremely intense flavor). f Based on the 0–15 Spectrum Universal Intensity scale (0 = not springy, dry, soft, crumbles, airy; 15 = very springy, juicy, hard, defined particle size, dense). g SEM = Standard error of the mean.
3.4. Storage effects on sensory profiles of sliced ham As shown in Table 8, storage resulted in changes in sensory aromatics, feeling factors, tastes, and texture attributes. On week 0, cooked pork aromatic was highest and then decreased to just detectable throughout the remaining storage period. Cured lean aromatic was initially low at week 0, but increased by week 2 and remained consistently high during the storage period. After 2
All plum ingredient treatments increased the percentage of cook loss in cured hams, but did not affect the vacuum-package purge or the sliced vacuum-package purge at 21-days post storage. Hams with DP were slightly darker in color having more off-color (brown). All treatments increased redness when measured by the colorimeter, but the DP color was much more intense and atypical of the traditional cured pork when compared to FP, PP and the control. TBARS values were not affected by any treatment and inclusion plum ingredients at the 5% level slightly increased Allo– Kramer shear values (decreased tenderness). Salty taste was reduced and sweet taste increased by the inclusion of 5% plum ingredients. Overall, the inclusion of plum ingredients in hams had minimal effects on other sensory attributes. Based on these results, the injection of fresh/dried plum ingredients into cured ham at 2.5% or 5% may not be acceptable due to reductions in product yield and changes in product color. Acknowledgments This research was supported by Texas AgriLife Research (HATCH-8111) and the California Dried Plum Board. References [AMSA] American Meat Science Assn. (1995). Research guidelines for cookery, sensory evaluation and instrumental measurements of fresh meat. Chicago, III: American Meat Science Assn., Natl. Live Stock and Meat Board. AOAC (2000). Official methods of analysis (17th ed.). Gaithersburg, MD: Association of Official Analytical Chemists.
M.T. Nuñez de Gonzalez et al. / Meat Science 83 (2009) 74–81 Cross, H. R., Moen, R., & Stanfield, M. S. (1978). Training and testing of judges for sensory analysis of meat quality. Food Technology, 32(7), 48–54. Decker, K. J. (1999). Designing moister meats: A plum assignment. A supplement to food product design. Available from:. Donovan, J. L., Meyer, A. S., & Waterhouse, A. L. (1998). Phenolic composition and antioxidant activity of prunes and prune juice (Prunus domestica). Journal of Agricultural and Food Chemistry, 46, 1247–1252. Fang, N., Yu, S., & Prior, R. (2002). LC/MS/MS characterization of phenolic constituents in dried plums. Journal of Agricultural and Food Chemistry, 50, 3579–3585. Katsaras, K., & Budras, K. D. (1993). The relationship of the microstructure of cooked ham to its properties and quality. Lebensmittel Wissenschaft und Technologie, 26, 229–234. Kreuzer, H. (2001). Research reveals the power of dried plums. A supplement to food product design. Available from: . Lee, E. J., & Ahn, D. U. (2005). Quality characteristics of irradiated turkey breast rolls formulated with plum extract. Meat Science, 71, 300–305. Leheska, J. M., Boyce, J., Brooks, J. C., Hoover, L. C., Thompson, L. D., & Miller, M. F. (2006). Sensory attributes and phenolic content of precooked pork breakfast sausage with fruit purees. Journal of Food Science, 71(3), S249–S252. Meilgaard, M., Civille, G. V., & Carr, B. T. (1999). Sensory evaluation techniques. Boca Raton, Florida: CRC Press, Inc..
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Nuñez de Gonzalez, M. T., Boleman, R. M., Miller, R. K., Keeton, J. T., & Rhee, K. S. (2008a). Antioxidant properties of dried plum ingredients in raw and precooked pork sausage. Journal of Food Science, 73(5), H63–H71. Nuñez de Gonzalez, M. T., Hafley, B. S., Boleman, R. M., Miller, R. K., Rhee, K. S., & Keeton, J. T. (2008b). Antioxidant properties of plum concentrates and powder in precooked roast beef to reduce lipid oxidation. Meat Science. doi: 10.1016/ j.meatsci.2008.04.014. O’Neill, D. J., Lynch, P. B., Troy, D. J., Buckley, D. J., & Kerry, J. P. (2003). Effects of PSE on the quality of cooked hams. Meat Science, 64, 113–118. Rhee, K. S. (1978). Minimization of further lipid peroxidation in the distillation 2thiobarbituric acid test of fish and meat. Journal of Food Science, 43(6), 1776–1781. Ò SAS Institute. (1995). SAS user’s guide. Cary, NC.: SAS Institute. Tarladgis, B. G., Watts, B. M., Younathan, M. T., & Dugan, L. R. (1960). A distillation method for the quantitative determination of oxidative rancidity in foods. Journal of American Oil Chemists’ Society, 37(1), 44–48. USDA-FSIS (1999). US Department of Agriculture-Food Safety Inspection Service. Appendix B: Compliance guidelines for cooling heat-treated meat and poultry products (stabilization). Available from:. Wang, H., Cao, G., & Prior, R. L. (1996). Total antioxidant capacity of fruits. Journal of Agricultural and Food Chemistry, 44, 701–705.
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Qualitative effects of fresh and dried plum ingredients on vacuum-packaged, sliced hams M.T. Nuñez de Gonzalez a, B.S. Hafley b, R.M. Boleman c, R.M. Miller d, K.S. Rhee d, J.T. Keeton e,* a
Department of Food Technology, Universidad de Oriente, Núcleo Nueva Esparta, Escuela de Ciencias Aplicadas del Mar, Isla de Margarita 6301, Venezuela Tyson Foods, 1825 Ford Ave., Springdale, AR 72764, United States c Byan Independent School District, 1920 N. Earl Rudder Freeway, Bryan, TX 77808, United States d Department of Animal Science, Texas A&M University, 338 Kleberg Center, College Station, TX 77843-2471, United States e Department of Nutrition and Food Science, Texas A&M University, 122 Kleberg Center, College Station, TX 77843-2253, United States b
a r t i c l e
i n f o
Article history: Received 12 August 2008 Received in revised form 27 February 2009 Accepted 3 April 2009
Keywords: Plum juice concentrates Ham Color Lipid oxidation
a b s t r a c t Boneless ham muscles (Semimembranosus + Adductor) were injected (20% w/w) with a curing brine containing no plum ingredient (control), fresh plum juice concentrate (FP), dried plum juice concentrate (DP), or spray dried plum powder (PP) at 2.5% or 5%. Hams were cooked, vacuum-packaged, stored at <4 °C and evaluated at 2-week intervals over 10 week. Evaluations were performed on sliced product to determine cook loss, vacuum-package purge, Allo–Kramer shear force, 2-thiobarbituric acid-reactive substances (TBARS), proximate analysis, objective color, sensory panel color and sensory attributes. FP, DP and 2.5% PP increased (P < 0.05) cook loss by 2% to 7% depending on treatment and level, but the highest cook loss (17.7%) was observed in hams with 5% PP. Shear force values increased as the level of plum ingredient increased (P < 0.05) from 2.5% to 5%, and the highest shear values were observed in hams containing 5% FP. There were no differences (P > 0.05) in lipid oxidation among treatments as determined by TBARS and sensory evaluation. FP and PP ham color was similar to the control, but DP had a more intense atypical color of cured ham. Minimal changes in physical, chemical and sensory properties were observed during storage of all treatments. Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction Dried plum puree contains indigenous chemical compounds that serve specific functions in foods: pectin aids in moisture retention, while malic acid enhances flavor, and sorbitol acts as a natural humectant. Phenolic compounds present in dried plum puree have been reported to be the main contributors of its antioxidant properties (Donovan, Meyer, & Waterhouse, 1998; Fang, Yu, & Prior, 2002; Kreuzer, 2001; Wang, Cao, & Prior, 1996). Because of its potential benefits, dried plum puree has been approved by USDA for use in ground beef destined for the US school lunch program. Hamburgers containing 3–5% dried plum puree have been shown to retain more moisture (after cooking) and were rated by students to be equal or better than hamburger products from major fast food chains (Decker, 1999). Moisture retention in that study was improved 15.8% in precooked patties reheated to
* Corresponding author. Tel.: +1 979 845 3975; fax: +1 979 862 6842. E-mail address: [email protected] (J.T. Keeton). 0309-1740/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2009.04.002
102 °C and held in warming trays for up to 4 h. Leheska et al. (2006) found that the addition of dried plum puree to precooked pork breakfast sausage can increase phenolics that may be nutritionally beneficial while also having consumer appeal. Nuñez de Gonzalez, Boleman, Miller, Keeton, and Rhee (2008a) indicated that the inclusion of 3% dried plum puree (DP) or 3% or 6% dried plum and apple puree (DPA) increased moisture and decreased fat content of raw and precooked pork sausages. Moreover, they found that DP used at 3% or 6% levels was as effective as a combination BHA/BHT (0.02%) for retarding lipid oxidation. Similarly, Lee and Ahn (2005) found that the addition of 2% plum extract or higher was effective at retarding lipid oxidation while enhancing juiciness in irradiated turkey breast rolls. Previous research with plum juice concentrates in roast beef (Nuñez de Gonzalez et al., 2008b) has shown a retention and enhancement of red color during refrigerated storage, a reduction in lipid oxidation and no detrimental effects on sensory attributes of precooked roast beef. Thus, the objective of this study was to determine if the inclusion of different levels of plum juice concentrates could improve quality, retain cured color during refrigerated storage and retard lipid oxidation in sliced vacuum-packaged, brine-injected hams.
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2. Materials and methods
2.2. Determination of cook loss
2.1. Ham processing
Chilled hams were weighed prior to opening the cook-in bags to obtain cooked, packaged weights. Individual hams were then removed from the package, drained thoroughly, and the cooked meat weights and empty package weights were recorded to calculate total cook loss as follows:
Fresh, chilled, trimmed, boneless, inside ham muscles (Semimembranosus + Adductor), USDA-IMPS # 402, weighing 0.9 to 1.8 kg were acquired from Tyson Foods Inc. (3–4 days postmortem), Houston, Texas. Inside ham muscles had been previously trimmed of fat and membranes and were ready for injection upon arrival. Hams were prepared in a state inspected (Texas Department of Health), commercial-scale pilot plant located in the Rosenthal Meat Science and Technology Center at Texas A&M University. A total of 168 hams (Table 1) or 24 hams per treatment were randomized and injected (Inject Star, Model BI-72, Brookfield, CT) with a brine solution (20% by weight of raw product) containing (1) no plum ingredient (control), (2) 2.5% or 5% fresh plum juice concentrate (FP), (3) 2.5% or 5% dried plum juice concentrate (DP), (4) 2.5% or 5% spray dried plum powder (PP) rehydrated in the curing brine. All plum ingredients used in this study were obtained through the California Dried Plum Board from Sunsweet Growers Inc., Yuba City, CA. The other ingredients, as percent after injection into the product and thermal processing, included food grade salt (2.5%, Salt Culinox 999 food grade, Morton International Inc., Chicago IL), dextrose (0.9%, Newly WedsÒ Foods, Bedford Park, IL), alkaline phosphate (0.35%, BifisolÒ512, BK Giulini Co, Simi Valley, CA), potassium lactate (3%, Purasal P HiPure 60, Purac America Inc., Lincolnshire, IL), sodium nitrite (0.19%, Heller’s modern cure, Heller Seasoning and Ingredients Inc., Chicago, IL), sodium erythorbate (0.49%, FCC Heller Seasoning and Ingredients Inc., Chicago, IL), and water. After brine injection, the hams were allowed to drain to remove excess brine and then re-weighed, and pumped weights were recorded to determine the percent pump. The hams were vacuum tumbled (Model VT500, Leland Southwest Inc., Ft. Worth, TX; 846.6 mbar, 4–5 rpm) in a room maintained at 65 °C for 1 h to aid brine ingredient distribution and absorption. Following tumbling, product weights were recorded. Then, hams were vacuumpackaged in CryovacÒ cook-in bags (type CN530, product # 97725, 30.48 cm by 60.96 cm, Cryovac North America, Duncan, SC) and re-weighed, and packaged weights were recorded. Prior to cooking, hams were stored overnight in a cooler maintained at <4 °C to allow for brine equalization. The hams were cooked using an incremental cook cycle in a steam-heated smokehouse (Model 1000, Alkar, DEC International Inc., Lodi, WI) to achieve a product endpoint temperature of 71.1 °C. The smokehouse was set for the following conditions: 1 h 60 °C, 2 h at 68.3 °C, 1 h at 76.7 °C and 2–4 h at 85 °C. After cooking, the hams were cooled to 37.7 °C by showering with cold water for 6 to 8 min. Finally, the products were cooled according to USDA-FSIS (1999, Appendix B) guidelines and stored in cardboard boxes 2–3 d in the dark at <4 °C. Table 1 Experimental design of ham allocations by treatment and storage time. Treatmenta
Control FP 2.5% FP 5% DP 2.5% DP 5% PP 2.5% PP 5%
Storage time (week)
Total
0
2
4
6
8
10
4 4 4 4 4 4 4
4 4 4 4 4 4 4
4 4 4 4 4 4 4
4 4 4 4 4 4 4
4 4 4 4 4 4 4
4 4 4 4 4 4 4 Total
24 24 24 24 24 24 24 168
a Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder.
Cook lossð%Þ ¼ ½raw weight cooked weight=raw weight 100 After determining cook loss, hams assigned to storage treatments (2, 4, 6, 8, and 10 week) were vacuum-packaged (UltravacÒ 2100, vacuum setting 7 and seal setting 7, KOCH Inc., Kansas City, MO) in CryovacÒ bags (type BH620T, product # 9D640, 33.02 cm by 66.04 cm, Cryovac North America, Duncan, SC) and stored in a cooler maintained at <4 °C for their respective storage period. At the end of each designated storage period, hams from each treatment were split in half, sliced and evaluated for vacuum-package purge, Allo–Kramer shear force, descriptive attribute sensory panel evaluation, color space values (L*, a*, b*), lipid oxidation, and proximate analysis. An additional set of sliced samples were stored 21 d to evaluate vacuum purge at the end of the 21 d period (Fig. 1). All sample slices were vacuum-packaged in CryovacÒ bags (type B540, product # 90184, 17.78 cm by 30.48 cm, Cryovac North America, Duncan, SC) and stored at <4 °C until analyses could be performed the following day. 2.3. Sliced vacuum-package purge at 21-d post ham storage At the end of each designated storage period (0, 2, 4, 6, 8, 10 week), a 454 g sample consisting of 0.31-cm thick slices from each ham was vacuum-packaged and stored in the dark for an additional 21 d at <4 °C. After 3 week, ham slices from each treatment were weighed to obtain a total package weight. Slices were then removed from the package, patted dry with a towel to remove excess moisture, and reweighed. Purge was calculated as total package weight minus package and sample weights. Percent vacuumpackage purge was determined using the following formula:
Vacuum package purgeð%Þ ¼ ½ham weight with purge ham weight without purge= ham weight with purge 100 2.4. Color determination L*, a*, b* color space values for the ham treatments at each designated storage time were recorded using a Minolta Colorimeter (Model CR-300, Minolta Corp., Ramsey, NJ)), with an 8-mm viewing port and illuminant D65. The instrument was calibrated with a white standard tile (L* = 97.55, a* = -0.02, b* = 1.56 set to channel 00). Color measurements were made on each slice per treatment by dividing the slice into three imaginary triangular sections imitating from the center of the slice and randomly taking a measurement within each section. The results were expressed as positive L* (lightness), a* (redness) and b* (yellowness) color space values. 2.5. Measurement of lipid oxidation Lipid oxidation of each treatment at each designated storage time was determined by 2-thiobarbituric acid-reactive substances (TBARS) procedure of Tarladgis, Watts, Younathan, and Dugan (1960) as modified by Rhee (1978). Each sample was analyzed in duplicate and results were expressed as mg of malonaldehyde (MDA) per kg of meat.
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Raw Hams (n = 24 per treatment/storage combination) Treatments: -Control -2.5% FP - 5% FP -2.5 % DP - 5% DP -2.5% PP -5% PP
Injection (20%)/Cooking/Chilling Cook loss determination Packaging (whole pieces)
Store (whole pieces) at 4°C for 10 wk
Slice whole pieces at each test week (0, 2, 4, 6, 8 and 10) for physicochemical and sensory analyses
Sliced 0.7 cm: -Allo-Kramer shear force -Sensory evaluation -Proximate analysis
Sliced 0.48 cm: -Vacuum-package purge -Color evaluations (L*, a*, b*) -Lipid oxidation (TBARS)
Sliced 0.31 cm: -Vacuum-package purge at 21 d poststorage
Fig. 1. Flow chart of ham processing, and physicochemical and sensory analyses.
2.6. Allo–Kramer shear force determination Allo–Kramer shear force measurements were performed on each treatment at the end of each designated storage period using an Instron Universal Testing Machine (Model 1011, Instron Corporation, Houston, TX). A standardized specimen size (2 by 5 cm2) was cut, weighed and placed flat in a 10-blade Allo–Kramer shear cell attached to a 500 kg load cell with a standard load range setting of 100 kg. Kilograms of shear force were recorded and divided by the sample weight to determine the shear force in kg/g of sample. This value was then converted to Newtons/g by multiplying kg 9.8. 2.7. Proximate analysis Percentages of moisture (AOAC, 2000, method 950.46), fat (AOAC, 2000, method 985.15), and protein (AOAC, 2000, method 992.15) were determined on finished products. Slices from hams assigned to each treatment at the 0 week storage period were homogenized in a food processor (Model R6, Robot Coupe S.A., Bagnolet, France) before sampling. Moisture and fat content (%) were determined using a convection air-dry oven and Soxhlet ether extraction methods, respectively. Crude protein percentage was determined by the Dumas combustion method to release gaseous N2 (Leco FP-528 Protein Analyzer, St. Joseph, MO). The procedure was standardized using oatmeal (Part No 502–276, %N = 9.56 ± 0.04). Percent crude protein was calculated as 6.25 times the percent nitrogen. All analyses of the samples were performed in duplicate. 2.8. Sensory evaluation Descriptive attribute analysis was performed on hams samples for each treatment and evaluated by a 7-member trained expert descriptive attribute sensory panel in the Texas A&M University
Sensory Testing Facility. Panelists were trained according to the procedures of Cross, Moen, and Stanfield (1978), AMSA (1995) and Meilgaard, Civille, and Carr (1999), and had more than five years of experience in SpectrumTM descriptive flavor and texture analysis (Meilgaard et al., 1999). The panel underwent an orientation session using hams prepared without antioxidant (control ‘‘as is”) and with antioxidant treatments (2.5% or 5% FP, 2.5% or 5% DP and 2.5% or 5% PP). Panel-specific training was conducted for 6 d. Panelists underwent performance evaluation as specified in the guidelines developed by AMSA (1995) prior to initiation of the study to assure that panelists were sufficiently trained. Samples were evaluated for aromatics (cooked pork, cured lean, cured fat, chemical taste, canned meat, and fresh/dried plum); basic tastes (salt, sour, bitter and sweet); feeling factors (astringent, metallic, and chemical burn) and texture attributes (springiness, juiciness, hardness, cohesiveness, and denseness). All samples were scored using the 0–15 Spectrum Universal intensity scale (Meilgaard et al., 1999) where 0 = absence of an attribute and 15 = extremely intense. In addition, panelists evaluated texture (springiness, juiciness, hardness, cohesiveness and denseness) using the 0–15 Spectrum Universal Intensity scale (Meilgaard et al., 1999) where 0 = not springy, dry, soft, crumbles, airy and 15 = very springy, juicy, hard, defined particle size, dense for each attribute. Reference standards for the sensory attributes that were used for the evaluation of ham are shown in Table 2. Ham samples from each treatment were evaluated at 2 week intervals. On each testing day, 7 samples were evaluated per day during one session. The order of the treatments was randomized and a warm-up was presented to judges before sample evaluation to ensure that they were familiar with the treatment attributes to be tested. The stimuli used for warm-up were hams from a control formulation. The ham samples were labeled with random 3-digit numbers and placed in clear 6-oz samples cups with lids. Panelists received two randomly selected samples (2.54 cm squares) from each ham that was maintained at 4–6 °C. Testing was conducted
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Table 2 Reference standards for sensory attributes and their intensities based on 0–15 Spectrum Universal intensity scale (0 = absent, 15 = extremely intense) established after consensus discussions with the expert panel. Sensory attribute
Reference standard
Scale value
Aromatics Cooked pork Cured lean Cured fat Chemical taste Canned meat Fresh/dried plum
Concentrated pork broth Ham (Oscar Mayer, Kraft Foods Global, Inc., Northfield, IL, USA) Beef hot dog (Oscar Mayer, Kraft Foods Global, Inc., Northfield, IL, USA) Cherry juice with 500 ppm bleach added (odor only) Canned chicken (SwansonÒ, Campbell Soup Co., Camden, NJ, USA) Prunes placed in mouth
15 12 5.5 15 15 15
Feeling factors Astringent Metallic Chemical burn
Cooked sample of liver, 1.27 cm Black tea (LiptonÓ, Englewood Cliffs, NJ, USA) bag placed in hot water and steeped for 1 h White vinegar (H.J. Heinz Co., Pittsburg, PA, USA)
15 6.5 15
Basic tastes Salt Sour Bitter Sweet
Potato chips (Pringles, Procter & Gamble, Cincinnati, OH, USA) Lemon juice (Real LemonÒ, Mott’s Inc., Stanford, CT,USA) Caffeine (0.15% solution) Chocolate bar (The Hershey Co., PA, USA)
13 8.0 10.0 10.0
Textures Springiness Juiciness Hardness Cohesiveness Denseness
Marshmallow (miniature, Wal-Mart Inc., Bentonville, AR, USA) Apple (Red Delicious variety) Hard candy (Life SaversÒ, WM. Wrigley JR. Co., Chicago, IL, USA) Candy chews (Starburst, Master-foods USATM, Hackettstown, NJ, USA) Malted milk balls (Whopper, The Hershey Co., PA, USA)
9.5 10.0 14.5 12.5 6.0
in isolated booths fitted with a breadbox server and red incandescent lighting to mask color differences. Unsalted crackers, ricotta cheese and distilled water were available to judges to clear their palate of residual flavors between samples. The trained panelists also evaluated ham samples for subjective color. Slices from each treatment were selected at random and displayed for evaluation of color intensity, greyness, off-color, and iridescence. Panelists scored ham slices for overall color using an 8point descriptive scale (1 = grey; 8 = dark reddish pink). Using a 6-point descriptive scale panelists also scored percent surface discoloration (grey and/or brown) (1 = no/0% surface grey color, no/0% surface brown color; 6 = total/100% surface grey color, total/100% surface brown color and iridescence (1 = none, 0%; 6 = very strong, 100%). All samples were evaluated subjectively under standard room fluorescent lighting (Econ-o-watt F40CW/RS/EW, 34 W, Philips Electronics North America, New York, NY). After color evaluation by the sensory panel, L* (lightness), a* (redness), and b* (yellowness) color space values were determined on the same ham slices using a Minolta colorimeter (Model CR300, Minolta Corporation, New Jersey). 2.9. Experimental design and statistical analysis The experiment was designed as a complete randomized factorial design (7 ingredient treatments 6 storage times). Ingredient treatments included a control (no antioxidant), 2.5% and 5% FP, 2.5% and 5% DP, and 2.5% and 5% PP. Twenty-four hams were randomly assigned to the treatment and storage combinations (Table 1). Hams were cooked and then stored at <4 °C for 0, 2, 4, 6, 8 and 10 weeks. At 2-week intervals, samples were assessed for vacuumpackage purge, Allo–Kramer shear force, TBARS, color space values, sensory attributes and sensory color for 10 weeks. Proximate analysis was performed on finished products from each ingredient treatment. Due to cost constraints, the entire experiment was performed one time with 4 hams allocated to each treatment (7) and storage (6) combination (Table 1). Thus, a total of 24 experiment units were assigned to each treatment within a 10-week storage period. Data were analyzed as a 7 6 factorial design using the General Linear Model (GLM) procedure of the Statistical Analysis System
(SAS, 1995). The main effects for the model were level of ingredients (FP, DP and DP) at 0%, 2.5% or 5% of the cooked weight and storage time (0, 2, 4, 6, 8, or 10 weeks). Analysis of variance was used to determine statistical differences among the main effects and their interactions with a significant level of P < 0.05. Least squares means were used to identify significant treatment effects. Sensory evaluation data were pooled across panelists and were analyzed as previously described.
3. Results and discussion 3.1. Effect of fresh and dried plum ingredients on physical and chemical properties of precooked ham The injection of fresh and dried plum ingredients into boneless, cured ham muscles affected percent cook loss, objective color, and Allo–kramer shear value (Table 3). Incorporation of plum juice concentrates or spray dried powder into precooked cured hams increased cook loss by 2–7%, depending on treatments and levels. FP tended to increase percent cook loss with increasing level of plum ingredient while notable increases (P < 0.05) were observed as DP and PP levels increased from 2.5% to 5%. The highest cook loss (17.7%) was observed in hams containing 5% PP. O’Neill, Lynch, Troy, Buckley and Kerry (2003) reported a similar cook loss percentage of 16.9% in normal cooked hams. Even with changes in percent cook loss, the addition of various fresh and dried plum ingredients had no effect on vacuum-package purge or sliced vacuum-package purge 21 days post storage. The addition of FP or PP (2.5% or 5%) did not affect objective L* (lightness) color space values. However, incorporation of DP, which has a slightly darker in color than FP and PP, lowered (P < 0.05) L* values (i.e., darkened ham slice color slightly). Redness (a*) values were higher for all plum treatments as compared to the control and were incrementally higher with 5% DP or PP than the 2.5% levels of the respective ingredients. Hams injected with DP had the highest (P < 0.05) a* (redness) color space values, but the color was not typical of the traditional reddish pink color of cured pork as noted by a* values of the treatments. Hams containing FP or PP were redder (P < 0.05) than control hams by only 1–2 a* units, but these differ-
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Table 3 Least squares means for percent cook loss, vacuum-package purge, sliced vacuum-package purge at 21-d post storage, L* a* b* color space values, TBARS values, and Allo–Kramer shear force values of cured, boneless ham with fresh/dried plum ingredients. Treatmentf
Cook loss (%)
Vacuum-package purge (%)
Sliced vacuum-package purge at 21-d post storage (%)
Color space values L* a* b*
Control FP 2.5% FP 5% DP 2.5% DP 5% PP 2.5% PP 5% SEMg
10.6a 12.6b 13.7bc 13.0b 14.8c 12.9b 17.7d 0.6
2.8 2.5 2.4 2.8 2.5 2.7 2.5 0.2
2.8 2.7 2.9 3.2 3.0 2.7 2.7 0.2
61.9cd 61.6cd 60.1abc 59.8ab 58.5a 61.4bc 63.4d 0.6
a–e f g
12.4 13.0 12.7 11.9 12.7 12.3 12.6 0.3
Allo–Kramer shear force value (Newtons/g sample)
0.12 0.14 0.11 0.11 0.12 0.12 0.14 0.1
44.1ab 42.1a 51.9c 47.0b 51.0c 46.1b 51.0c 1.1
Least squares means in the same column without a common superscript letter differ (P < 0.05). Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder. SEM = Standard error of the mean.
ences were small and may not be perceived by the human eye. Yellowness, as measured by b* color space value, was unaffected (P > 0.05) by the incorporation of the plum ingredients. Lee and Ahn (2005) reported that the addition of plum extract puree (PEP) increased a* and b* values and decreased L* value of turkey breast rolls due to the darker color of plum extract. Also, these researchers indicated that the color of turkey rolls with 3% PEP was dark and might not be appealing to consumers. Thus, these results may indicate potential difficulties with consumer acceptance of the off-red color produced with the injection of DP, while FP may yield a more acceptable color. TBARS values of hams injected with plum ingredients at 2.5% or 5% were similar (P > 0.05) to that of the control. The presence of sodium nitrite, sodium erythorbate and alkaline phosphates in ham enhances pigment stabilization, inhibits lipid and pigment oxidation, and thus would be expected to contribute some antioxidant properties in comparison to uncured products. Unlike the antioxidant effect of plum concentrates in precooked pork sausage (Nuñez de Gonzalez et al., 2008a) and roast beef (Nuñez de Gonzalez et al., 2008b), hams were not as susceptible to lipid oxidation due to inclusion of sodium nitrite and alkaline phosphates. Allo–Kramer shear force values of ham samples increased as the level of plum ingredient increased (P < 0.05) from 2.5% to 5%. The higher loss of moisture during cooking for the 5% level likely caused the increase in Allo–Kramer shear force values that indicate a slight reduction in tenderness. Results for percent moisture, fat, and protein values are presented in Table 4. Ham samples containing 5% DP and PP were lower (P < 0.05) in moisture content, while samples containing 2.5% DP were slightly higher (P < 0.05) when compared to the control. Since the percent cook loss was significantly higher (P < 0.05) for the 5%
Table 4 Least squares means for percent moisture, fat, and protein of cured, boneless ham with fresh/dried plum ingredients. Treatmentg Control FP 2.5% FP 5% DP 2.5% DP 5% PP 2.5% PP 5% SEMh a–f
4.7a 7.0c 7.3c 10.2d 11.2e 5.8b 7.0c 0.4
TBARS (mg MDA/kg)
Moisture (%) c
70.3 70.6cd 70.3c 70.8d 68.2a 69.8b 68.2a 0.1
Fat (%) d
2.3 2.6e 0.8a 1.0b 1.5c 1.1b 3.0f 0.1
Protein (%) 23.8b 22.8a 24.7d 24.2c 25.4e 24.0bc 25.4e 0.1
Least squares means in the same column without a common superscript letter differ (P < 0.05). g Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder. h SEM = Standard error of the mean.
DP and PP samples, lower percentages of moisture would be expected. With lower percentages of moisture, percent fat would normally be expected to be higher; however, percent fat was variable which is possibly due to the retention of plum solids during cooking. Different levels of solids retention also would cause variations in the individual components of the proximate analysis. For example, hams injected with FP at 5% and DP at 2.5% or 5% had higher (P < 0.05) levels of protein as compared to the control, but hams with 2.5% FP had a lower level of protein. Changes in percent fat and percent protein were small and likely varied in response to cooking loses and retained solids. In contrast to the results of the present study, Lee and Ahn (2005) reported that the composition, especially moisture and lipid contents, of RTE (Ready-to-eat) turkey breast rolls with plum extract puree-added (1%, 2% and 3%) were similar to that of control. 3.2. Storage effects on physical and chemical properties of precooked ham Table 5 summarizes cook loss, vacuum-package purge, sliced vacuum-package purge at 21-d post storage, objective color, TBARS, and Allo–kramer shear values during storage of refrigerated vacuum-packaged hams with plum ingredients. No differences (P > 0.05) were noted in cook loss for whole hams over a 10-week storage period, but percent vacuum-package purge increased as storage progressed. After 21-d post storage, vacuum-package purge of ham slices was not different except at week 6. Objective color values during refrigerated vacuum-package storage did change slightly, but not more than 1–2 units from the control. L* (lightness) color space values increased slightly (P < 0.05) after 6 and 10 weeks of refrigerated storage, while a* (redness) and b* (yellowness) values decreased slightly (P < 0.05) at week 4 and 10. TBARS values fluctuated slightly (up and down) over the 10-week period of refrigerated vacuum-package storage, but tended to increase after 6 week. However, there were no clear patterns observed in TBARS values due to storage. Little to no changes was observed for Allo–Kramer shear force values except at week 10 when ham samples became slightly (P < 0.05) less tender. 3.3. Sensory properties of sliced ham with fresh and dried plum ingredients In general, most fresh/dried plum aromatics, with the exception of cured lean, were just above the threshold for detection in samples with plum ingredients. With the exception of FP 2.5% and PP 2.5%, which were not different from the control, only the fresh/ dried plum aromatic increased (P < 0.05) in treatments with the addition of plum ingredients (Table 6). The fresh/dried plum
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Table 5 Least squares means for percent cook loss, vacuum-package purge, sliced vacuum-package purge at 21-d post storage, L* a* b* color space values, TBARS values, and Allo–Kramer shear force values of cured, boneless ham stored under refrigerated conditions. Storage week
Cook loss (%)
Vacuum-package Purge (%)
Sliced vacuum-package purge at 21-d post storage (%)
Color space values L*
a*
b*
0 2 4 6 8 10 SEMg
14.3 13.3 13.1 13.6 13.6 13.9 0.6
NTf 2.1a 2.5ab 2.8bc 2.7bc 2.9c 0.13
2.9bc 3.3c 3.1c 2.3a 3.2bc 2.4ab 0.2
60.3ab 61.6bc 58.8a 62.9c 60.2ab 62.0c 0.6
8.0b 7.9b 6.8a 7.9b 8.2b 6.7a 0.3
13.1c 13.1c 12.1b 13.1c 13.1c 10.7a 0.2
a–e f g
TBARS (mg MDA/kg)
Allo–Kramer shear force value (Newtons/g sample)
0.11bc 0.02a 0.08b 0.17d 0.13c 0.23e 0.2
48.0bc 46.1ab 44.1a 46.1ab 49.0cd 51.9d 1.1
Least squares means in the same column without a common superscript letter differ (P < 0.05). NT, not tested. SEM = Standard error of the mean.
aromatic intensity was greatest in hams injected with 5% DP. Salt was the dominant taste, but it was less (P < 0.05) in hams with 5% plum ingredient. Sensory scores for sour taste of hams injected with plum material were not different from the control except that 5% PP was deemed slightly (P < 0.05) less sour. Similar to the plum aromatic, sweet taste increased (P < 0.05) in hams with a 5% level of ingredient likely due to the higher levels of sugars in the juice or powder concentrates. No textural differences in hams were noted due to plum ingredients. Likewise in a study performed by Katsaras and Budras (1993), the textural attributes of cohesiveness and juiciness of high quality hams were not affected by the addition of plum ingredients. Overall, the inclusion of 5% plum ingredients increased the fresh/dried plum aromatic note and sweetness taste slightly, but decreased saltiness. As a consequence, only a few sensory attributes of ham were affected by the inclusion of plum ingredients and these only minimally. The addition of plum ingredients to ham was found to affect subjective color, off-color, and iridescence scores (Table 7). Compared to control hams, subjective color intensity scores were similar (P > 0.05) across plum treatments and levels with the exception
of hams containing 2.5% PP which were slightly more reddish pink (P < 0.05). Subjective color scores indicated that DP 2.5% and PP 5% tended to be more grey than the other plum treatments, but were not different from the control. In comparison, a* values (Table 3) indicated DP treatments to be redder, but these samples had slightly higher (P < 0.05) off-color (brown) scores in comparison to all other samples, regardless of level. Increasing the level of DP from 2.5% to 5% also increased (P < 0.05) scores for brown off-color due to the inherently darker pigments in DP. Iridescence scores were low overall, but ham samples containing 2.5% FP, 2.5% DP, and 5% PP had slightly more (P < 0.05) iridescence present than the control. Overall, some variations in color (redness) intensity of hams treated with fresh/dried plum ingredients were noted, but only PP 2.5% was of sufficient magnitude to be different from the control. Off-color was most notable for the DP treatment and some slight increase in iridescence was observed with low levels of FP and DP and a high level of PP. The observed changes in color indicate that the addition of DP to cured boneless hams may detrimentally affect product appearance, but that FP and PP would have a limited effect on appearance.
Table 6 Least squares means of descriptive attribute sensory panel scores for aromaticse, feeling factorse, basic tastese, and texturesf of cured, boneless ham with fresh/dried plum ingredients. Treatmentsg SEMh Control
FP 2.5%
FP 5%
DP 2.5%
DP 5%
PP 2.5%
PP 5%
Aromatics Cooked pork Cured lean Cured fat Chemical taste Canned meat Fresh/dried plum
1.3 6.9 1.7 0.2 0.7 0.0a
1.2 6.9 1.6 0.3 0.6 0.5ab
1.3 6.3 1.5 0.2 0.6 0.8b
1.2 6.8 1.6 0.2 0.6 0.8b
1.3 6.3 1.6 0.3 0.4 1.8c
1.3 7.0 1.7 0.3 0.7 0.2a
1.1 6.7 1.4 0.1 0.4 0.9b
0.2 0.2 0.2 0.1 0.1 0.2
Feeling factors Astringent Metallic Chemical burn
2.5 1.9 0.2
2.4 1.8 0.4
2.2 1.8 0.5
2.3 1.8 0.5
2.2 1.7 0.4
2.5 1.8 0.6
2.0 1.5 0.3
0.1 0.1 0.1
Basic taste Salt Sour Bitter Sweet
7.6cd 1.8bcd 1.4 1.4a
7.2cd 1.9cd 1.5 1.5ab
5.9a 1.6ab 1.3 1.8bc
7.1bc 2.1d 1.6 1.5ab
6.4ab 1.9bcd 1.4 2.0c
7.9d 1.7abc 1.7 1.3a
6.0a 1.5a 1.2 1.9c
0.3 0.1 0.2 0.1
Textures Springiness Juiciness Hardness Cohesiveness Denseness
5.4 4.5 5.2 6.0 6.7
5.5 4.4 5.3 5.7 6.6
5.3 4.4 5.3 6.0 6.5
5.4 4.4 5.1 6.1 6.4
5.3 4.5 5.5 6.1 6.7
5.3 4.6 5.3 6.1 6.7
5.1 4.6 5.1 5.9 6.3
0.2 0.2 0.2 0.2 0.2
a–d e f g h
Least squares means in the same row without a common superscript letter differ (P < 0.05). Based on the 0–15 Spectrum Universal Intensity scale (0 = absence of flavor; 15 = extremely intense flavor). Based on the 0–15 Spectrum Universal Intensity scale (0 = not springy, dry, soft, crumbles, airy; 15 = very springy, juicy, hard, defined particle size, dense). Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder. SEM = Standard error of the mean.
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Table 7 Least squares means of descriptive attribute sensory panel scores for colore, grey colorf, off colorg, and iridescenceh of cured, boneless ham slices with fresh/dried plum ingredients.
Table 9 Least squares means of descriptive attribute sensory panel scores for colore, grey colorf, off colorg, and iridescenceh of cured, boneless ham stored under refrigerated condition.
Treatmenti
Color
Grey color
Off color
Iridescence
Storage week
Color
Grey color
Off color
Iridescence
Control FP 2.5% FP 5% DP 2.5% DP 5% PP 2.5% PP 5% SEMj
4.4abc 4.8cd 4.8cd 4.0a 4.7bcd 5.1d 4.2ab 0.2
1.3 1.1 1.1 1.6 1.4 1.1 1.3 0.2
1.5a 1.5a 1.4a 3.0b 3.9c 1.5a 1.7a 0.2
1.5a 2.1bc 1.4a 2.2bc 1.8ab 1.5a 2.3c 0.2
0 2 4 6 8 10 SEMi
4.5b 4.9b 4.8b 4.8b 4.1a 4.4ab 0.2
1.2b 0.6a 1.2b 1.4bc 1.5bc 1.9c 0.2
2.0 1.7 2.4 2.0 2.3 1.9 0.2
1.6ab 1.3a 2.2cd 1.7bc 2.2cd 1.9bcd 0.2
a–d
a–d
Least squares means in the same column without a common superscript letter differ (P < 0.05). e Based on a 8-point intensity scale (1 = grey; 8 = dark reddish pink). f Based on a 6-point intensity scale (1 = no/0% surface grey color; 6 = total/100% surface grey color). g Based on a 6-point intensity scale (1 = no/0% surface brown color; 6 = total/ 100% surface brown color). h Based on a 6-point intensity scale (1 = none, 0%; 6 = very strong, 100%). i Control = No plum ingredient; FP = Fresh plum juice concentrate; DP = Dried plum juice concentrate; PP = Spray dried plum powder. j SEM = Standard error of the mean.
Table 8 Least squares means of descriptive attribute sensory panel scores for aromaticse, feeling factorse, basic tastese, and texturesf of cured, boneless ham stored under refrigerated conditions. SEMg
Storage week 0
2
4
6
8
Aromatics Cooked pork Cured lean Cured fat Chemical taste Canned meat Fresh/dried plum
4.9b 3.2a 0.7a 0.7c 1.5c 0.4c
0.4a 7.7b 1.2b 0.1ab 0.6b 0.0a
0.3a 7.5b 2.1c 0.2ab 0.2a 0.1b
0.3a 7.6b 1.9c 0.0a 0.1a 0.0a
0.2a 7.4b 1.9c 0.3b 0.3ab 0.0
0.2 0.2 0.1 0.1 0.1 0.2
Feeling factors Astringent Metallic Chemical burn
2.2 1.7 0.5bc
2.1 1.8 0.3ab
2.5 1.8 0.7c
2.2 1.6 0.1a
2.4 1.9 0.4abc
0.1 0.1 0.1
Basic tastes Salt Sour Bitter Sweet
6.5 1.6a 1.3a 1.1a
7.0 1.7ab 1.3a 1.7b
7.1 2.0bc 1.8b 1.7b
6.9 1.6a 1.4a 1.7b
7.0 2.0c 1.4a 1.9b
0.3 0.1 0.2 0.1
Textures Springiness Juiciness Hardness Cohesiveness Denseness
4.6a 4.3a 5.4bc 6.1bc 6.8b
5.5bc 4.2a 5.5c 6.3cd 6.7b
5.0ab 4.9b 5.4bc 6.5d 6.1a
5.6cd 5.1b 5.1ab 5.7b 6.0a
6.0d 4.1a 4.8a 5.3a 7.2b
0.2 0.2 0.2 0.2 0.2
Least squares means in the same column without a common superscript letter differ (P < 0.05). e Based on a 8-point intensity scale (1 = grey; 8 = dark reddish pink). f Based on a 6-point intensity scale (1/0% = no surface grey color; 6 = total/100% surface grey color). g Based on a 6-point intensity scale (1/0% = no surface brown color; 6 = total/ 100% surface brown color). h Based on a 6-point intensity scale (1 = none, 0%; 6 = very strong, 100%). i SEM = Standard error of the mean.
week of storage, chemical taste and canned meat aromatic scores both decreased (P < 0.05) in intensity while cured fat increased slightly (P < 0.05). Salt taste did not change during storage and remained the overall numerically dominant taste throughout storage. Sweet taste increased slightly after week 0 and remained through week 8. Sour taste scores were only slightly higher (P < 0.05) at 4 and 8 week. No consistent pattern was observed in texture scores over the storage period even though slight differences were observed on different test days. It appears that refrigerated storage of vacuum-packaged ham primarily caused a decline in cooked pork aroma and a corresponding increase in cured lean aroma. Evaluation of color intensity and off-color were not different (P > 0.05) due to storage and only a few small changes in grey color and iridescence of ham slices were noted by the sensory panel as a result of storage (Table 9). 4. Conclusion
a–d Least squares means in the same row without a common superscript letter differ (P < 0.05). e Based on the 0–15 Spectrum Universal Intensity scale (0 = absence of flavor; 15 = extremely intense flavor). f Based on the 0–15 Spectrum Universal Intensity scale (0 = not springy, dry, soft, crumbles, airy; 15 = very springy, juicy, hard, defined particle size, dense). g SEM = Standard error of the mean.
3.4. Storage effects on sensory profiles of sliced ham As shown in Table 8, storage resulted in changes in sensory aromatics, feeling factors, tastes, and texture attributes. On week 0, cooked pork aromatic was highest and then decreased to just detectable throughout the remaining storage period. Cured lean aromatic was initially low at week 0, but increased by week 2 and remained consistently high during the storage period. After 2
All plum ingredient treatments increased the percentage of cook loss in cured hams, but did not affect the vacuum-package purge or the sliced vacuum-package purge at 21-days post storage. Hams with DP were slightly darker in color having more off-color (brown). All treatments increased redness when measured by the colorimeter, but the DP color was much more intense and atypical of the traditional cured pork when compared to FP, PP and the control. TBARS values were not affected by any treatment and inclusion plum ingredients at the 5% level slightly increased Allo– Kramer shear values (decreased tenderness). Salty taste was reduced and sweet taste increased by the inclusion of 5% plum ingredients. Overall, the inclusion of plum ingredients in hams had minimal effects on other sensory attributes. Based on these results, the injection of fresh/dried plum ingredients into cured ham at 2.5% or 5% may not be acceptable due to reductions in product yield and changes in product color. Acknowledgments This research was supported by Texas AgriLife Research (HATCH-8111) and the California Dried Plum Board. References [AMSA] American Meat Science Assn. (1995). Research guidelines for cookery, sensory evaluation and instrumental measurements of fresh meat. Chicago, III: American Meat Science Assn., Natl. Live Stock and Meat Board. AOAC (2000). Official methods of analysis (17th ed.). Gaithersburg, MD: Association of Official Analytical Chemists.
M.T. Nuñez de Gonzalez et al. / Meat Science 83 (2009) 74–81 Cross, H. R., Moen, R., & Stanfield, M. S. (1978). Training and testing of judges for sensory analysis of meat quality. Food Technology, 32(7), 48–54. Decker, K. J. (1999). Designing moister meats: A plum assignment. A supplement to food product design. Available from:
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