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Fatty acid composition and quality characteristics of low-fat cooked sausages made with beef and chicken meat, tomato juice and sunflower oil
Meat Science 62 (2002) 253–258 www.elsevier.com/locate/meatsci
Fatty acid composition and quality characteristics of low-fat cooked sausages made with beef and chicken meat, tomato juice and sunflower oil . I. Yılmaz*, O. S¸ims¸ ek, M. Is¸ ıklı Department of Food Engineering, Faculty of Agriculture, Trakya University, 59030 Tekirdag˘, Turkey Received 5 August 2001; received in revised form 5 October 2001; accepted 13 December 2001
Abstract Low-fat (5.9–10.3% fat) cooked sausages were produced with seven different formulations. Sausages produced with total replacement of fat with sunflower oil had significantly lower oleic acid (C18:1) and higher linoleic (C18:2) and behenic (C22:0) fatty acid contents. Their ratio of TUFA/TS was 3.65 compared to 0.95–1.14 for the other sausages. Also these sausages had the lowest moisture content, highest overall palatability and were less firm. Sausages with tomato juice had the lowest pH value, total aerobic count and nitrite content, but were firmer. Sausages produced with reduced beef contents had lower fat contents, lower stearic (C18:0) and higher oleic (C18:1) fatty acid contents than sausages of high beef content, their texture was very soft and had the lowest score for juiciness. Finally the sausages with chicken meat had the lowest fat and highest salt contents, and lower stearic (C18:0) and higher linoleic (C18:3) fatty acid contents than those made with beef . Also their colour was lighter, less red and more yellow and they had the lowest flavor intensity and overall acceptability. # 2002 Elsevier Science Ltd. All rights reserved. Keywords: Beef; Chicken; Low-fat; Cooked sausage; Fatty acids
1. Introduction The American Heart Association and other health organizations have recommended that consumers should reduce total dietary fat intake to lower serum cholesterol concentrations in blood (AHA, 1986; Department of Health, 1994; NCEP, 1988). Therefore manufacturing foods such as low-fat meat products, is of both economic and health interest (Wirth, 1988). Increasing consumer demand for low-fat products has resulted in research in red meat products. Fat contents in the processed products can be readily reduced through formulation with leaner meats, but this is not cost-effective and may also lessen product quality (Hand, Hollingsworth, Calkins, & Mandigo, 1987; Hensley & Hand, 1995). Rust and Olson (1988) found that when the fat of a meat product is reduced below 15%, the quality changes significantly, especially the texture. * Corresponding author. Tel.: +90-282-293-1291; fax: +90-282293-1480. . E-mail address: [email protected] (I. Yılmaz).
Park, Rehee, Keeton, and Rehee (1989) and Park, Rehee, and Ziprin (1990) studied the properties of lowfat frankfurters manufactured by direct incorporation of high-oleic sunflower oil (HOSO) as a source of monounsaturated fat. They reported that low-fat frankfurters with the maximum allowable addition of water and HOSO could be manufactured without adverse effects on yield, texture or sensory properties. Bloukas and Paneras (1993) manufactured low fat frankfurters by direct incorporation of olive oil. These products would be highly desirable from a diet/health standpoint as they contain monounsaturated vegetable oil, have lower energy and higher protein contents. Diets with higher monounsaturated fat contents have been associated with decreases in coronary heart disease (Keys, 1970). Sausages often have fat contents between 8.94 and 19.33%, protein contents between 9 and 17%, moisture contents between 52.54 and 68.80%, and salt contents of 1.60 to 2.68% (Ertas¸ & Kolsarıcı, 1983; Sutton, Hand, & Newkirk, 1995; Sylvia, Claus, Marriott, & Eigel, 1994). Martin and Rogers (1993) studied beef-sausages of low fat content and reported protein, fat, and moisture contents of 15.5–16.4, 1.0–1.1, and 77.1–78.3%, respectively.
0309-1740/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved. PII: S0309-1740(01)00255-8
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Compositions of 14.4, 1.2–2.1, and 78.2–78.4%, respectively, for sausages made with 50% pork meat and 50% beef were found. The aim of this study was to evaluate and compare the compositional, nutritional and sensory properties of low-fat sausages produced with different meats and other ingredients.
2. Materials and methods 2.1. Sausages formulation and processing Seven types of cooked sausages were produced and the experimental design and formulations are given in Table 1. Ice/water and the following ingredients were also added in each treatment: ice/water 3000 g; sodium chloride 250 g; sodium nitrite 2 g; sodium phosphate 30 g; sodium ascorbate 4 g; monosodium glutamate 5 g; starch 350 g; and seasonings 60 g. Meat and fat were separately ground, then mixed in a bowl chopper while adding the salt. Ice was added in three stages until the temperature of the mixture reached 8 C, additives and spices were added and finally the starch. The mixture was taken out of the bowl chopper at 12 C. The batter was filled into collagen casings of 19–21 mm diameter. The sausages were then hung by metal rods and dried at 58 C for 20 min and smoked at 65 C for 25 min. The sausages were cooked at 74 C to a core temperature of 72 C in an oven. After cooking, they were cooled under running water for 15 min, then stored at 2– 4 C . All sausages were vacuum-packaged in polyethylene of oxygen permeability 7.06 ml/m2/24 h (23 C, 0% RH).
Fat extraction was carried out according to AOAC (1990). Methyl Esters (FAME) were prepared after alkaline hydrolysis, followed by methylation in methanol plus BF3. The final concentration of the FAME was approximately 7 mg/ml in heptane (AOAC, 1990). Analyses of the FAME by capillary GLC were carried out on a Hewlett-Packard 6890 chromatograph, equipped with a flame-ionization detector (FID) on a split injector (Chrompack, Middleburg, The Netherlands). A fused-silica capillary column was used, CPTM-Sil 88, 50 m0.25 mm i.d., 0.2 mm film; Chrompack. The column was operated isothermally at 177 C, injector and detector were kept at 250 C. The carrier gas was helium at a flow rate of 1 ml/min. DP-900 D25 Aoptical Sensor Reston (Viriginia, USA) was used to determine Hunter Lab color values and evaluation was done according to AOAC (1984). An Instron Universal Testing machine (Model 1140) was used to determine the texture of sausages using a 500 kg load at 20 mm/min (Bloukas & Paneras, 1993). Ten panelists evaluated the sensory characteristics of the sausages as described by Bloukas and Paneras (1993). The panalists were chosen on the basis of previous experience in evaluating sausages. The following attributes were evaluated on 8-point scales: firmness (8=extremely firm, 1=extremely soft), flavour intensity (8=extremely strong, 1=extremely weak to unpleasant), juiciness (8=extremely juicy, 1=extremely dry), overall palability (8=palatable, 1=unpalatable). Each attribute was discussed and tests were initiated after panalists were familiarized with the scales. 2.3. Microbiological analysis
2.2. Chemical and physical analysis Moisture, protein, starch, fat, salt and nitrite (ppm) contents and pH measurements were made according to the methods described by AOAC (1990).
AOAC (1998) methods were used to determine total aerobic bacterial, Escherichia coli, Staphylococcus aureus, Salmonella, Clostridium perfringens and moldsyeasts counts.
Table 1 Batter formulations of the sausage Treatmentsa
1. B-HSt 2. B-LSt 3. B-SO 4. B-TJ 5. RB 6. LB 7. CM a
Raw materials and ingredients (g) Beef meat 1.28% fat
Chicken meat 0.5% fat
Fat
Sunflower oil
Tomato juice
Starch
6000 6000 6000 6000 5700 5500 –
– – – – – – 6100
1100 1100 – 1200 1200 1200 1200
– – 1100 – – – –
– – – 300 – – –
400 350 350 350 350 350 350
B-HSt, beef meat–high starch; B-LSt, beef meat–low starch; B-SO, beef meat–sunflower oil; BTJ, beef meat–tomato juice; RB, reduced beef meat; LB, low beef meat; CM, chicken meat.
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Total aerobic counts were determined on Plate Count Agar (PCA), after incubation at 35 C for 48 h. The presence of E. coli was confirmed by VRBAMUG and the plates were incubated at 37 C for 48 h. Those giving positive fermentation and gas production in lactose broth were further characterized as E. coli using .indole, methyl red, Voges-Proskauer and citrate (IMVIC) identification tests. The presence of Staphylococcus aureus was tested by surface plating on prepoured and dried Baird Parker Agar with egg yolk tellurite enrichment. The plates were incubated at 37 C for 48 h. The presence of C. perfringens was tested by Trypticase Sulfide Neomycin and the plates were incubated at 37 C for 48 h. For the presence of Salmonella, samples enriched in Selenite Cysitein Broth were tested by Bismut Sulfide Agar. The plates were incubated at 35 C for 24 h. Confirmation of Salmonella was by Triple Sugar Iron. 2.4. Statistical analysis The data obtained from three replications were analysed by ANOVA using the SPSS statistical package program, and differences among the means were compared using Duncan’s Multiple Range test (Soysal, 1992).
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3. Results and discussions 3.1. Fatty acids While the ratio of total unsaturated fatty acids to total saturated fatty acids was 3.65 in the samples supplemented with SO, it was between 0.95 and 1.14 for the other samples (Table 2). The values of total saturated and polyunsaturated fatty acids are similar to those reported by Bloukas and Paneras (1993). While C22:0 (behenic acid) was found in the SO-supplemented-sausages, it was not found in the others. The total amount of saturated fatty acids was 21.5% in SO supplemented sausages, and between 46.7 and 51.1% in the others. However, oleic acid was lower in SO-supplemented samples. SO supplemented sausages contained lower amounts of total monosaturated fatty acids (P < 0.05) when compared with the others (Table 2) because of high linoleic acid and therefore lower oleic acid in sunflower oil. There were significant differences (P < 0.05) between the amounts of total polysaturated fatty acids of SO added sausagesand the others (Table 2). Mainly because SO contains high levels of linoleic acid. In addition, the sum of the essential fatty acids was higher in the SO-supplemented sausages. The sausages with SO thus had better nutritional properties than the others.
Table 2 Fatty acid composition of sausages Fatty acids (%)
Caprylic C8:0 Capric C10:0 Lauric C12:0 Miristic C14:0 Miristoleic C14:1 Pentadecanoic C15:0 Palmitic C16:0 Palmitoleic C16:1 Margaric C17:0 Stearic C18:0 Oleic C18:1 Linoleic C18:2 Linolenic C18:3 Arachidic C20:0 Eicosadienoic C20:2 Behenic C22:0 Total saturated Total monounsaturated Total polyunsaturated Total unsaturated Total unsaturated/total saturated
Treatments* 1
2
3
4
5
6
7
n.d. n.d. 0.2 2.6 1.6 0.4 25.1 5.2 0.1 22.5 38.2 3.1 0.8 0.2 n.d. n.d. 51.1a 45.0a 3.9b 48.9b 0.95
n.d. 0.1 0.2 2.7 1.6 0.4 24.5 5.6 0.6 19.0 41.9 2.5 0.7 0.2 n.d. n.d. 47.7a 49.1a 3.2b 52.3b 1.09
n.d. 0.1 0.1 0.9 0.5 n.d. 11.3 1.9 0.2 7.9 32.3 43.5 0.3 0.3 n.d. 0.7 21.5b 34.7b 43.8a 78.5a 3.65
n.d. 0.2 0.2 3.5 1.9 0.2 26.2 6.6 0.7 15.6 39.7 3.8 1.3 0.1 n.d. n.d. 46.7a 48.2a 5.1b 53.3b 1.14
0.1 0.1 0.1 3.1 1.9 0.3 26.0 6.6 0.6 19.9 37.8 2.7 0.5 0.2 0.1 n.d. 50.4a 46.3a 3.3b 49.6b 0.98
n.d. 0.1 0.2 2.8 1.6 0.4 24.9 5.6 0.7 17.8 41.6 3.5 0.8 n.d. n.d. n.d. 46.9a 48.8a 4.3b 53.1b 1.13
n.d. 0.1 0.1 3.0 1.7 0.3 25.4 5.9 0.7 20.5 39.6 1.9 0.6 0.2 n.d. n.d. 50.3a 47.2a 2.5b 49.7b 0.99
n.d., Not detected. a,b Means within the same row with different superscript letters are different (P< 0.05). *1. B-HSt, beef meat–high starch; 2. B-LSt, beef meat–low starch; 3. B-SO, beef meat–sunflower oil; 4. BTJ, beef meat–tomato juice; 5. RB, reduced beef meat; 6. LB, low beef meat; 7. CM, chicken meat.
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3.2.2. Protein The highest protein content was obtained from the sausages supplemented with SO. The differences between the protein contents of the sausages were significant (P < 0.05). However, the protein content of all sausages were within the standard for Turkish sausages (TS 980).Similar results were found by El-Khateib, ElRahman, Hamdy, and Lofti (1989) and Martin and Rogers (1993).
3.1.1. pH The pH of the sausages are given in Table 3. The addition of tomato juice significantly decreased (P < 0.05) the pH. The pH of all the other sausages were within the specifications Turkish sausages (TS 980) (Anonymous, 1984). Wirth (1987) and Tandler (1987) have reported similar pH values for these types of sausage. 3.2. Chemical composition
3.2.3. Fat content Chicken meat had a significant effect (P < 0.05) on the fat content of the sausages, probably due to it’s lower fat content. Also, reduction of beef from 6000 to 5500 g resulted in a significant (P < 0.05) reduction in the fat content. However, the fat content of the low-fat sausages was higher than reported by Martin and Rogers (1993), but similar to that reported by Bloukas and Paneras (1993) and Paneras and Bloukas (1994).
3.2.1. Moisture The chemical composition of the sausages is given in Table 3. Sausages produced with SO had the lowest (P < 0.05) moisture content. On the other hand the sausages produced with chicken meat had the highest (P < 0.05) moisture content because of the higher moisture content in chicken compared with red meat. Sausages produced with SO had a moisture content within Turkish standard (TS 980) values (Anonymous, 1984) but all the other sausages had moisture contents above 65%. Martin and Rogers (1993) and Sutton et al. (1995) reported similar results.
3.2.4. Starch Starch was added to the sausages to stabilize the emulsion by binding the excess water. However, it was
Table 3 Physico-chemical, microbiological and sensory attributes of low-fat sausages Parameters
Treatmentsa 1
2 c
3 a
4 c
5 d
6 e
7 b
6.24a
6.06
6.20
6.06
5.99
5.69
6.13
Chemical composition Moisture (%) Protein (%) Fat (%) Starch (%) Sodium chloride (%) Sodium nitrite (ppm)
65.74c 16.28b 9.86a 4.90a 2.01c 29.58
66.01c 16.30b 9.44a 4.12b 2.10bc 23.86
63.98d 17.93a 10.35a 3.40d 1.69d 21.77
68.84a 17.51a 5.94c 3.78c 2.31a 24.36
67.91b 15.70bc 9.28a 4.06b 2.15b 20.04
65.49c 15.35c 7.41b 4.73a 2.06bc 26.88
66.03c 17.53a 9.85a 3.39d 2.30a 29.24
Colour Lightness L Redness a Yellowness b Texture (N)
40.40c 18.21b 11.57bc 6.86d
42.61b 16.16c 9.57d 10.98b
42.16bc 18.88ab 11.65bc 8.43bc
63.60a 7.47d 15.65a 8.04c
42.17bc 17.76bc 14.53ab 12.55a
38.11d 20.84a 11.38c 7.45cd
42.57b 14.82cd 13.07b 11.97ab
Microbiological counts TPC count (log cfu/g)
5.41
4.25
4.57
4.77
3.57
5.00
3.92
Sensory attributes Firmnessf Flavour intensityg Juicinessh Overall palabilityi
6.3c 6.5b 6.5b 6.6ab
7.0a 6.8a 6.3c 6.5b
6.8ab 6.7a 6.7a 6.7a
6.1d 6.3c 6.5b 6.3c
6.3c 6.5b 6.5b 6.5b
6.5b 6.6ab 6.3c 6.7a
6.7ab 6.7a 6.5b 6.7a
pH
a,b,c,d,e
Means within the same row with different superscript letters are different (P<0.05). 8=Extremely firm, 1=extremely soft. g 8=Extremely strong, 1=extremely weak up unpleasant. h 8=Extremely juicy, 1=extremely dry. i 8=Platable, 1=unpalatable. *1 B-HSt, beef meat–high starch; 2 B-LSt, beef meat–low starch; 3 B-SO, beef meat–sunflower oil; 4 BTJ, beef meat–tomato juice; 5 RB, reduced beef meat; 6 LB, low beef meat; 7 CM, chicken meat. f
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higher in samples 1 (beef meat–high starch), 3 (beef meat–sunflower oil), 5 (reduced beef meat) and 6 (low beef meat), which were all above the 4% starch recommended in the Turkish Food Codex for meat products. 3.2.5. Salt content The salt content of the sausages is given in Table 3. The salt content was lowest in sausages supplemented with SO and highest in those made with chicken meat (P < 0.05), since in these two sausages the added salt was the lowest and highest respectively. The salt content of sausages with SO was 1.69% and that of sausages with chicken meat 2.31%. According to Wirth (1991) frankfurter type sausages of 1.6% salt content are regarded as ‘‘mildly salty’’ while those with 2.4% are very salty. The salt content of other sausages ranged between 2.01 and 2.15%, which is within the limits defined for the salt content of frankfurter type sausages. 3.2.6. Nitrite content The nitrite content is also given in Table 3. No significant differences in nitrite content among the samples (P > 0.05) was found. Mu¨ller (1991) reported similar results, while Bloukas and Paneras (1993) found higher nitrite content in low-fat frankfurters. 3.3. Microbiological results The highest total count of microorganism was found in sample 1 while the lowest count was obtained in those containing tomato juice (Table 3), probably due to the low pH of the tomato juice-added sausages. The differences between total counts were significant (P < 0.05). E. coli, S. aureus, Salmonella spp., C. perfringens and yeasts-molds were not detected suggesting good hygienic quality in processing although the smoking and cooking procedures are probably the main reasons. 3.3.1. Colour, firmness and sensory attributes The instrumental colour and firmness of the sausages are given in Table 3. Sausages made with chicken meat had significantly (P < 0.05) higher L and b values and lower a values than all other sausages. Therefore, they were lighter, less red and more yellow than the other sausages. These differences are probably due to the low myoglobin content of chicken meat. It has been reported that firmness and flexibility increases in sausages supplemented with sunflower oil (Park et al., 1990) but the values for firmness were not high for the SO-added sausages in our experiment (Table 3). According to the sensory analysis, the sausages with SO had the highest acceptability (P < 0.05) (Table 3).
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4. Conclusion Low-fat sausages can be produced with the seven different formulations. Moreover, the sausages produced with the addition of sunflower oil are the most healthy due to higher contents of unsaturated and essential fatty acids and there was no negative sensorial characteristics in the SO-supplemented sausages.
References AHA (1986). Dietary guidilines for healty adult Americans. American Heart Association, 74(Circulation), 1465–1475. Anonymous (1984). TS 980 Sosis standardı. Ankara: Tu¨rk Standartlari Enstitu¨su¨ (in Turkish). AOAC (1984). Official methods for the analysis (14th ed.). Arlington Washington DC: Association of Official Analytical Chemists. AOAC (1990). Official methods for the analysis (15th ed.). Arlington Washington DC: Association of Official Analytical Chemists. AOAC (1998). Bacteriological analytical manual (8th ed.). Gaithersburg, MD, USA: Association of Official Analytical Chemists. Bloukas, J. G., & Paneras, E. D. (1993). Substuting olive oil for pork backfat affects quality of low fat frankfurters. Journal of Food Science, 58, 705–709. Department of Health. (1994). Report on health and social subjects, No46. Nutritional aspects of cardiovascular disease. London: HMSO. El-Khateib, T., El-Rahman, H. A., Hamdy, M., & Lotfi, A. (1989). Poultry meat products in Egypt. Fleischwirtschaf, 3, 69–70. Ertas¸ , A. H., & Kolsarıcı, N. (1983). Salam, sosis ve sucuklarda hidroksiprolin miktarı u¨zerine aras¸ tırma. Gy´da, 5, 209–215. Hand, L. W., Hollingsworth, C. A., Calkins, C. R., & Mandigo, R. W. (1987). Effects of preblending reduced fat and salt levels on frankfurter characteristics. Journal of Food Science, 52, 1149–1151. Hensley, J. L., & Hand, L. W. (1995). Formulation and chopping temperature effects on beef frankfurters. Journal of Food Science, 60, 55–58. Keys, A. (1970). Coronary heart disease in seven countries. Circulation, 44(1). Martin, J. W., & Rogers, R. W. (1993). Cure levels, processing methods and meat source effects on low fat frankfurters. Journal of Food Science, 58(1), 59–61. Mu¨ller, W. D. (1991). Curing and smoking. Fleischwirtschaf, 2, 8–18. NCEP (National Cholesterol Education Program). (1988). The effect of diet on plasma lipids, lipoproteins and coronary heart disease. Journal of the American Diet Association, 88, 1373–1400. Paneras, E. D., & Bloukas, J. G. (1994). Vegetable oils replace pork backfat for low-fat frankfurters. Journal of Food Science, 59, 725–733. Park, J., Rehee, K. S., Keeton, J. T., & Rehee, K. C. (1989). Properties of low fat frankfurters containig monounsaturated and omega-3 polyunsaturated oil. Journal of Food Science, 54, 500. Park, J., Rehee, K. S., & Ziprin, Y. A. (1990). Low-fat frankfurters with elevated levels of water and oleic acid. Journal of Food Science, 55, 871. Rust, R., & Olson, D. (1988). Making good ‘‘lite’’ sausage. Meat and Poultry, 34, 10. Soysal, I., 1992. Biometrinin Temel Prensibleri. (Principles of Biometric Analysis.) T. Uni. Tekirdag Zir. Fak. Yay. No: 95, Tekirdag. Sutton, D. S., Hand, L. W., & Newkirk, K. A. (1995). Reduced fat, high moisture beef frankfurters as affected by chopping temperature. Journal of Food Science, 60(3), 580–582. Sylvia, S. F., Claus, J. R., Marriott, N. G., & Eigel, W. N. (1994). Low fat, high moisture frankfurters: effects of temperature and water during extended mixing. Journal of Food Science, 59(5), 937– 940.
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Tandler, K. (1987). Frankfurter type sausages: shelf life and packaging of the fresh product. Fleischwirtschaf, 2, 25–30. Wirth, F. (1987). Curing: colour formation and colour retention in Frankfurter type sausages. Fleischwirtschaf, 2, 3–9.
Wirth, F. (1988). Technologies for making fat-reduced meat products. Fleischwirtschaf, 68(9), 1153. Wirth, F. (1991). Reducing the fat and sodium content of meat products. Fleischwirtschaf, 3, 294–297.
Fatty acid composition and quality characteristics of low-fat cooked sausages made with beef and chicken meat, tomato juice and sunflower oil . I. Yılmaz*, O. S¸ims¸ ek, M. Is¸ ıklı Department of Food Engineering, Faculty of Agriculture, Trakya University, 59030 Tekirdag˘, Turkey Received 5 August 2001; received in revised form 5 October 2001; accepted 13 December 2001
Abstract Low-fat (5.9–10.3% fat) cooked sausages were produced with seven different formulations. Sausages produced with total replacement of fat with sunflower oil had significantly lower oleic acid (C18:1) and higher linoleic (C18:2) and behenic (C22:0) fatty acid contents. Their ratio of TUFA/TS was 3.65 compared to 0.95–1.14 for the other sausages. Also these sausages had the lowest moisture content, highest overall palatability and were less firm. Sausages with tomato juice had the lowest pH value, total aerobic count and nitrite content, but were firmer. Sausages produced with reduced beef contents had lower fat contents, lower stearic (C18:0) and higher oleic (C18:1) fatty acid contents than sausages of high beef content, their texture was very soft and had the lowest score for juiciness. Finally the sausages with chicken meat had the lowest fat and highest salt contents, and lower stearic (C18:0) and higher linoleic (C18:3) fatty acid contents than those made with beef . Also their colour was lighter, less red and more yellow and they had the lowest flavor intensity and overall acceptability. # 2002 Elsevier Science Ltd. All rights reserved. Keywords: Beef; Chicken; Low-fat; Cooked sausage; Fatty acids
1. Introduction The American Heart Association and other health organizations have recommended that consumers should reduce total dietary fat intake to lower serum cholesterol concentrations in blood (AHA, 1986; Department of Health, 1994; NCEP, 1988). Therefore manufacturing foods such as low-fat meat products, is of both economic and health interest (Wirth, 1988). Increasing consumer demand for low-fat products has resulted in research in red meat products. Fat contents in the processed products can be readily reduced through formulation with leaner meats, but this is not cost-effective and may also lessen product quality (Hand, Hollingsworth, Calkins, & Mandigo, 1987; Hensley & Hand, 1995). Rust and Olson (1988) found that when the fat of a meat product is reduced below 15%, the quality changes significantly, especially the texture. * Corresponding author. Tel.: +90-282-293-1291; fax: +90-282293-1480. . E-mail address: [email protected] (I. Yılmaz).
Park, Rehee, Keeton, and Rehee (1989) and Park, Rehee, and Ziprin (1990) studied the properties of lowfat frankfurters manufactured by direct incorporation of high-oleic sunflower oil (HOSO) as a source of monounsaturated fat. They reported that low-fat frankfurters with the maximum allowable addition of water and HOSO could be manufactured without adverse effects on yield, texture or sensory properties. Bloukas and Paneras (1993) manufactured low fat frankfurters by direct incorporation of olive oil. These products would be highly desirable from a diet/health standpoint as they contain monounsaturated vegetable oil, have lower energy and higher protein contents. Diets with higher monounsaturated fat contents have been associated with decreases in coronary heart disease (Keys, 1970). Sausages often have fat contents between 8.94 and 19.33%, protein contents between 9 and 17%, moisture contents between 52.54 and 68.80%, and salt contents of 1.60 to 2.68% (Ertas¸ & Kolsarıcı, 1983; Sutton, Hand, & Newkirk, 1995; Sylvia, Claus, Marriott, & Eigel, 1994). Martin and Rogers (1993) studied beef-sausages of low fat content and reported protein, fat, and moisture contents of 15.5–16.4, 1.0–1.1, and 77.1–78.3%, respectively.
0309-1740/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved. PII: S0309-1740(01)00255-8
. I. Yılmaz et al. / Meat Science 62 (2002) 253–258
254
Compositions of 14.4, 1.2–2.1, and 78.2–78.4%, respectively, for sausages made with 50% pork meat and 50% beef were found. The aim of this study was to evaluate and compare the compositional, nutritional and sensory properties of low-fat sausages produced with different meats and other ingredients.
2. Materials and methods 2.1. Sausages formulation and processing Seven types of cooked sausages were produced and the experimental design and formulations are given in Table 1. Ice/water and the following ingredients were also added in each treatment: ice/water 3000 g; sodium chloride 250 g; sodium nitrite 2 g; sodium phosphate 30 g; sodium ascorbate 4 g; monosodium glutamate 5 g; starch 350 g; and seasonings 60 g. Meat and fat were separately ground, then mixed in a bowl chopper while adding the salt. Ice was added in three stages until the temperature of the mixture reached 8 C, additives and spices were added and finally the starch. The mixture was taken out of the bowl chopper at 12 C. The batter was filled into collagen casings of 19–21 mm diameter. The sausages were then hung by metal rods and dried at 58 C for 20 min and smoked at 65 C for 25 min. The sausages were cooked at 74 C to a core temperature of 72 C in an oven. After cooking, they were cooled under running water for 15 min, then stored at 2– 4 C . All sausages were vacuum-packaged in polyethylene of oxygen permeability 7.06 ml/m2/24 h (23 C, 0% RH).
Fat extraction was carried out according to AOAC (1990). Methyl Esters (FAME) were prepared after alkaline hydrolysis, followed by methylation in methanol plus BF3. The final concentration of the FAME was approximately 7 mg/ml in heptane (AOAC, 1990). Analyses of the FAME by capillary GLC were carried out on a Hewlett-Packard 6890 chromatograph, equipped with a flame-ionization detector (FID) on a split injector (Chrompack, Middleburg, The Netherlands). A fused-silica capillary column was used, CPTM-Sil 88, 50 m0.25 mm i.d., 0.2 mm film; Chrompack. The column was operated isothermally at 177 C, injector and detector were kept at 250 C. The carrier gas was helium at a flow rate of 1 ml/min. DP-900 D25 Aoptical Sensor Reston (Viriginia, USA) was used to determine Hunter Lab color values and evaluation was done according to AOAC (1984). An Instron Universal Testing machine (Model 1140) was used to determine the texture of sausages using a 500 kg load at 20 mm/min (Bloukas & Paneras, 1993). Ten panelists evaluated the sensory characteristics of the sausages as described by Bloukas and Paneras (1993). The panalists were chosen on the basis of previous experience in evaluating sausages. The following attributes were evaluated on 8-point scales: firmness (8=extremely firm, 1=extremely soft), flavour intensity (8=extremely strong, 1=extremely weak to unpleasant), juiciness (8=extremely juicy, 1=extremely dry), overall palability (8=palatable, 1=unpalatable). Each attribute was discussed and tests were initiated after panalists were familiarized with the scales. 2.3. Microbiological analysis
2.2. Chemical and physical analysis Moisture, protein, starch, fat, salt and nitrite (ppm) contents and pH measurements were made according to the methods described by AOAC (1990).
AOAC (1998) methods were used to determine total aerobic bacterial, Escherichia coli, Staphylococcus aureus, Salmonella, Clostridium perfringens and moldsyeasts counts.
Table 1 Batter formulations of the sausage Treatmentsa
1. B-HSt 2. B-LSt 3. B-SO 4. B-TJ 5. RB 6. LB 7. CM a
Raw materials and ingredients (g) Beef meat 1.28% fat
Chicken meat 0.5% fat
Fat
Sunflower oil
Tomato juice
Starch
6000 6000 6000 6000 5700 5500 –
– – – – – – 6100
1100 1100 – 1200 1200 1200 1200
– – 1100 – – – –
– – – 300 – – –
400 350 350 350 350 350 350
B-HSt, beef meat–high starch; B-LSt, beef meat–low starch; B-SO, beef meat–sunflower oil; BTJ, beef meat–tomato juice; RB, reduced beef meat; LB, low beef meat; CM, chicken meat.
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Total aerobic counts were determined on Plate Count Agar (PCA), after incubation at 35 C for 48 h. The presence of E. coli was confirmed by VRBAMUG and the plates were incubated at 37 C for 48 h. Those giving positive fermentation and gas production in lactose broth were further characterized as E. coli using .indole, methyl red, Voges-Proskauer and citrate (IMVIC) identification tests. The presence of Staphylococcus aureus was tested by surface plating on prepoured and dried Baird Parker Agar with egg yolk tellurite enrichment. The plates were incubated at 37 C for 48 h. The presence of C. perfringens was tested by Trypticase Sulfide Neomycin and the plates were incubated at 37 C for 48 h. For the presence of Salmonella, samples enriched in Selenite Cysitein Broth were tested by Bismut Sulfide Agar. The plates were incubated at 35 C for 24 h. Confirmation of Salmonella was by Triple Sugar Iron. 2.4. Statistical analysis The data obtained from three replications were analysed by ANOVA using the SPSS statistical package program, and differences among the means were compared using Duncan’s Multiple Range test (Soysal, 1992).
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3. Results and discussions 3.1. Fatty acids While the ratio of total unsaturated fatty acids to total saturated fatty acids was 3.65 in the samples supplemented with SO, it was between 0.95 and 1.14 for the other samples (Table 2). The values of total saturated and polyunsaturated fatty acids are similar to those reported by Bloukas and Paneras (1993). While C22:0 (behenic acid) was found in the SO-supplemented-sausages, it was not found in the others. The total amount of saturated fatty acids was 21.5% in SO supplemented sausages, and between 46.7 and 51.1% in the others. However, oleic acid was lower in SO-supplemented samples. SO supplemented sausages contained lower amounts of total monosaturated fatty acids (P < 0.05) when compared with the others (Table 2) because of high linoleic acid and therefore lower oleic acid in sunflower oil. There were significant differences (P < 0.05) between the amounts of total polysaturated fatty acids of SO added sausagesand the others (Table 2). Mainly because SO contains high levels of linoleic acid. In addition, the sum of the essential fatty acids was higher in the SO-supplemented sausages. The sausages with SO thus had better nutritional properties than the others.
Table 2 Fatty acid composition of sausages Fatty acids (%)
Caprylic C8:0 Capric C10:0 Lauric C12:0 Miristic C14:0 Miristoleic C14:1 Pentadecanoic C15:0 Palmitic C16:0 Palmitoleic C16:1 Margaric C17:0 Stearic C18:0 Oleic C18:1 Linoleic C18:2 Linolenic C18:3 Arachidic C20:0 Eicosadienoic C20:2 Behenic C22:0 Total saturated Total monounsaturated Total polyunsaturated Total unsaturated Total unsaturated/total saturated
Treatments* 1
2
3
4
5
6
7
n.d. n.d. 0.2 2.6 1.6 0.4 25.1 5.2 0.1 22.5 38.2 3.1 0.8 0.2 n.d. n.d. 51.1a 45.0a 3.9b 48.9b 0.95
n.d. 0.1 0.2 2.7 1.6 0.4 24.5 5.6 0.6 19.0 41.9 2.5 0.7 0.2 n.d. n.d. 47.7a 49.1a 3.2b 52.3b 1.09
n.d. 0.1 0.1 0.9 0.5 n.d. 11.3 1.9 0.2 7.9 32.3 43.5 0.3 0.3 n.d. 0.7 21.5b 34.7b 43.8a 78.5a 3.65
n.d. 0.2 0.2 3.5 1.9 0.2 26.2 6.6 0.7 15.6 39.7 3.8 1.3 0.1 n.d. n.d. 46.7a 48.2a 5.1b 53.3b 1.14
0.1 0.1 0.1 3.1 1.9 0.3 26.0 6.6 0.6 19.9 37.8 2.7 0.5 0.2 0.1 n.d. 50.4a 46.3a 3.3b 49.6b 0.98
n.d. 0.1 0.2 2.8 1.6 0.4 24.9 5.6 0.7 17.8 41.6 3.5 0.8 n.d. n.d. n.d. 46.9a 48.8a 4.3b 53.1b 1.13
n.d. 0.1 0.1 3.0 1.7 0.3 25.4 5.9 0.7 20.5 39.6 1.9 0.6 0.2 n.d. n.d. 50.3a 47.2a 2.5b 49.7b 0.99
n.d., Not detected. a,b Means within the same row with different superscript letters are different (P< 0.05). *1. B-HSt, beef meat–high starch; 2. B-LSt, beef meat–low starch; 3. B-SO, beef meat–sunflower oil; 4. BTJ, beef meat–tomato juice; 5. RB, reduced beef meat; 6. LB, low beef meat; 7. CM, chicken meat.
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3.2.2. Protein The highest protein content was obtained from the sausages supplemented with SO. The differences between the protein contents of the sausages were significant (P < 0.05). However, the protein content of all sausages were within the standard for Turkish sausages (TS 980).Similar results were found by El-Khateib, ElRahman, Hamdy, and Lofti (1989) and Martin and Rogers (1993).
3.1.1. pH The pH of the sausages are given in Table 3. The addition of tomato juice significantly decreased (P < 0.05) the pH. The pH of all the other sausages were within the specifications Turkish sausages (TS 980) (Anonymous, 1984). Wirth (1987) and Tandler (1987) have reported similar pH values for these types of sausage. 3.2. Chemical composition
3.2.3. Fat content Chicken meat had a significant effect (P < 0.05) on the fat content of the sausages, probably due to it’s lower fat content. Also, reduction of beef from 6000 to 5500 g resulted in a significant (P < 0.05) reduction in the fat content. However, the fat content of the low-fat sausages was higher than reported by Martin and Rogers (1993), but similar to that reported by Bloukas and Paneras (1993) and Paneras and Bloukas (1994).
3.2.1. Moisture The chemical composition of the sausages is given in Table 3. Sausages produced with SO had the lowest (P < 0.05) moisture content. On the other hand the sausages produced with chicken meat had the highest (P < 0.05) moisture content because of the higher moisture content in chicken compared with red meat. Sausages produced with SO had a moisture content within Turkish standard (TS 980) values (Anonymous, 1984) but all the other sausages had moisture contents above 65%. Martin and Rogers (1993) and Sutton et al. (1995) reported similar results.
3.2.4. Starch Starch was added to the sausages to stabilize the emulsion by binding the excess water. However, it was
Table 3 Physico-chemical, microbiological and sensory attributes of low-fat sausages Parameters
Treatmentsa 1
2 c
3 a
4 c
5 d
6 e
7 b
6.24a
6.06
6.20
6.06
5.99
5.69
6.13
Chemical composition Moisture (%) Protein (%) Fat (%) Starch (%) Sodium chloride (%) Sodium nitrite (ppm)
65.74c 16.28b 9.86a 4.90a 2.01c 29.58
66.01c 16.30b 9.44a 4.12b 2.10bc 23.86
63.98d 17.93a 10.35a 3.40d 1.69d 21.77
68.84a 17.51a 5.94c 3.78c 2.31a 24.36
67.91b 15.70bc 9.28a 4.06b 2.15b 20.04
65.49c 15.35c 7.41b 4.73a 2.06bc 26.88
66.03c 17.53a 9.85a 3.39d 2.30a 29.24
Colour Lightness L Redness a Yellowness b Texture (N)
40.40c 18.21b 11.57bc 6.86d
42.61b 16.16c 9.57d 10.98b
42.16bc 18.88ab 11.65bc 8.43bc
63.60a 7.47d 15.65a 8.04c
42.17bc 17.76bc 14.53ab 12.55a
38.11d 20.84a 11.38c 7.45cd
42.57b 14.82cd 13.07b 11.97ab
Microbiological counts TPC count (log cfu/g)
5.41
4.25
4.57
4.77
3.57
5.00
3.92
Sensory attributes Firmnessf Flavour intensityg Juicinessh Overall palabilityi
6.3c 6.5b 6.5b 6.6ab
7.0a 6.8a 6.3c 6.5b
6.8ab 6.7a 6.7a 6.7a
6.1d 6.3c 6.5b 6.3c
6.3c 6.5b 6.5b 6.5b
6.5b 6.6ab 6.3c 6.7a
6.7ab 6.7a 6.5b 6.7a
pH
a,b,c,d,e
Means within the same row with different superscript letters are different (P<0.05). 8=Extremely firm, 1=extremely soft. g 8=Extremely strong, 1=extremely weak up unpleasant. h 8=Extremely juicy, 1=extremely dry. i 8=Platable, 1=unpalatable. *1 B-HSt, beef meat–high starch; 2 B-LSt, beef meat–low starch; 3 B-SO, beef meat–sunflower oil; 4 BTJ, beef meat–tomato juice; 5 RB, reduced beef meat; 6 LB, low beef meat; 7 CM, chicken meat. f
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higher in samples 1 (beef meat–high starch), 3 (beef meat–sunflower oil), 5 (reduced beef meat) and 6 (low beef meat), which were all above the 4% starch recommended in the Turkish Food Codex for meat products. 3.2.5. Salt content The salt content of the sausages is given in Table 3. The salt content was lowest in sausages supplemented with SO and highest in those made with chicken meat (P < 0.05), since in these two sausages the added salt was the lowest and highest respectively. The salt content of sausages with SO was 1.69% and that of sausages with chicken meat 2.31%. According to Wirth (1991) frankfurter type sausages of 1.6% salt content are regarded as ‘‘mildly salty’’ while those with 2.4% are very salty. The salt content of other sausages ranged between 2.01 and 2.15%, which is within the limits defined for the salt content of frankfurter type sausages. 3.2.6. Nitrite content The nitrite content is also given in Table 3. No significant differences in nitrite content among the samples (P > 0.05) was found. Mu¨ller (1991) reported similar results, while Bloukas and Paneras (1993) found higher nitrite content in low-fat frankfurters. 3.3. Microbiological results The highest total count of microorganism was found in sample 1 while the lowest count was obtained in those containing tomato juice (Table 3), probably due to the low pH of the tomato juice-added sausages. The differences between total counts were significant (P < 0.05). E. coli, S. aureus, Salmonella spp., C. perfringens and yeasts-molds were not detected suggesting good hygienic quality in processing although the smoking and cooking procedures are probably the main reasons. 3.3.1. Colour, firmness and sensory attributes The instrumental colour and firmness of the sausages are given in Table 3. Sausages made with chicken meat had significantly (P < 0.05) higher L and b values and lower a values than all other sausages. Therefore, they were lighter, less red and more yellow than the other sausages. These differences are probably due to the low myoglobin content of chicken meat. It has been reported that firmness and flexibility increases in sausages supplemented with sunflower oil (Park et al., 1990) but the values for firmness were not high for the SO-added sausages in our experiment (Table 3). According to the sensory analysis, the sausages with SO had the highest acceptability (P < 0.05) (Table 3).
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4. Conclusion Low-fat sausages can be produced with the seven different formulations. Moreover, the sausages produced with the addition of sunflower oil are the most healthy due to higher contents of unsaturated and essential fatty acids and there was no negative sensorial characteristics in the SO-supplemented sausages.
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