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. 2010 Dec 17;48(4):498–501. doi: 10.1007/s13197-010-0193-z

Efficacy of soy protein isolate as a fat replacer on physico-chemical and sensory characteristics of low-fat paneer

S Siva Kumar 1,✉, S Balasubramanian 2, A K Biswas 3, M K Chatli 3, S K Devatkal 3, J Sahoo 3
PMCID: PMC3551177  PMID: 23572778

Abstract

The nutritional and textural properties of low fat paneer using soy protein isolate (SPI) as fat replacer was investigated. The physico-chemical and sensory characteristics of 4 types of paneer made of low-fat milk (3% milk fat (MF) and 10% solids-not-fat (SNF)) and SPI of 0 (T1), 0.1 (T2), 0.2 (T3) and 0.3% SPI (T4) were compared with high fat paneer (TC) made of high fat milk (6% MF and 9% SNF). CaCl2 (0.2%, w/v) was used as coagulant at 75 ± 1°C. Increased level of SPI in paneer increased yield, protein, ash, moisture content and decreased fat, moisture protein ratio, lactose and calorie contents. Titratable acidity and pH varied in narrow range. Instrumental firmness was higher (p ≤ 0.05) in T1-T4 than in TC. The gumminess, chewiness and firmness showed the same trend. Resilience and cohesiveness values showed no significant difference among the samples. Hunter colour L values showed a decreasing, and a and b values increasing trend with increasing levels of SPI. Sensory appearance and colour scores were lower (p ≤ 0.05) for T1-T4 than TC. More than 0.2% SPI imparted beany flavour to paneer.

Keywords: Low-fat paneer, Soy protein isolate, Physico chemical, Texture, Colour, Sensory quality

Introduction

Paneer (Indian cheese) is a heat-cum-acid coagulated traditional dairy product used in variety of Indian culinary dishes. Paneer preferably prepared from buffalo milk contains high fat (25%). Various fat replacers like soy milk, soy flour, calcium groundnut isolates/ calcium soy isolates and whey protein concentrate were tried to prepare low fat paneer. Calcium groundnut isolates/ calcium soy isolates addition in skim milk and vegetable mixture increased the protein content to 50% (Kanawjia et al. 1990). Addition of 0.1% CaCl2 as a coagulant in cow milk at 85°C improved the quality and yield of cow milk paneer (Singh and Kanawjia 1988). Soy protein isolate (SPI) contains high quality protein and fat less than 1% (no saturated fat). Addition of SPI also improved the texture of the products, flavour and also acts as an emulsifier (SANA 2004). According to Nurcan and Mustafa (2004) fat replacers decrease the textural values like hardness, springiness, gumminess and chewiness but increase cohesiveness. Thus, present study was focused to examine the nutritional and textural properties of low fat paneer prepared by addition of SPI as fat replacer and CaCl2 as coagulant.

Materials and methods

Milk was obtained from dairy farm of the Institute and standardized to 3% milk fat (MF) and 10% solids-not-fat (SNF) by adding skim milk powder (Verka brand) procured from local market. The SPI was obtained from Du Point India Pvt Ltd., Gurgacon (imported from Solae Company, Hong Hong/US). CaCl2 (extra pure) was procured from Sisco Research Laboratories, Mumbai. Other chemicals used for experiment were of analytical quality grade.

Preparation of paneer

Four types of paneer including high fat paneer (HFP) (TC 6% MF and 9% SNF) and SPI 0% (T1), 0.1% (T2), 0.2%, (T3) and 0.3% (T4) incorporated low-fat paneer (SLFP) were prepared separately, using CaCl2 (0.2% w/v) as coagulant. The processing technology of paneer was standardized on the basis of preliminary trials. SPI was added at 50°C and 0.2% CaCl2 (w/v) at 60°C continuing heating up to 75 ± 1°C to ensure its complete coagulation.The coagulated mass was pressed in paneer mould kept under 3 kgf static load for 20 min. Paneer was transferred to chilled water and drained for few minutes before packing in low density polyethylene (100 micron) films.

Physico-chemical analysis

Protein (micro-Kjeldahl method), fat (ISI 1981), and lactose (ISI 1973), moisture, ash and titratable acidity (AOAC 1995) and pH of paneer O’Keffe et al. (1976) were determined. The processing parameters such as yield, frying loss were determined by weighing samples. Calorie content was calculated on the basis of 4, 9 and 4 formula.

Sensory evaluation

All the products were subjected to sensory evaluation using 8- point descriptive scale (Keeton 1983) by a team of 6 panel members in the laboratory.

Texture analysis

Texture profile analysis was conducted using Texture analyzer (TA-HDi, Stable micro system, UK). Sample size of 2 cm × 2 cm × 2 cm was subjected to pre-test speed (2 mm/sec), post-test speed (5 mm/sec) and test speed (1 mm/sec) with a deformation of 3 mm, time (2 sec) having a load cell of 500 N. A compression platform of 25 mm was used as a probe. Firmness, gumminess, springiness, resilience chewiness, and cohesiveness were calculated from the force-time plot.

Colour profile analysis

Colour profile was measured using Hunter Colour Lab (Mini XE, portable type, Hunter Color Associates Inc, Reston, VA) having setting of cool white light (D65) and 2°. L (100 brightness/ 0 lightness), a (+redness/−greenness), b (+yellowness/−blueness) values were recorded.

Statistical analysis

Each experiment was repeated thrice and analytical parameter was carried out in duplicate (n = 6). The mean and standard deviations were calculated using statistical software SPSS following the procedure of Snedecor and Cochran (1994). The statistical significance of the data was determined at p ≤ 0.05 and was compared using Duncan’s multiple range tests.

Results and discussion

Physico-chemical quality

Table 1 reveals that fat and fat on dry matter has been reduced (p ≤ 0.05) from TC to T1-T4. Lower fat and lactose contents in T2, T3, and T4 as compared to T1 may be due to increased yield. Similar findings were reported in paneer (Chawla et al. 1987; Singh and Kanawjia 1991).

Table 1.

Effect of soy protein isolate (SPI) incorporation on the physico-chemical attributes of low fat paneer

High fat paneer (TC) SPI level, %
0 (T1) 0.1 (T2 ) 0.2 (T3) 0.3% (T4)
Moisture, % 54.8 ± 0.45b 57.7 ± 0.52a 57.7 ± 0.58a 57.8 ± 0.39a 57.9 ± 0.21a
Fat, %, (w/w) 23.1 ± 0.79a 13.2 ± 1.02b 13.0 ± 0.85b 12.7 ± 0.54bc 12.4 ± 0.32c
Fat, %, (db) 56.8 ± 0.41a 31.1 ± 0.90b 30.7 ± 0.84b 30.0 ± 0.81c 29.3 ± 0.71c
Protein, % 17.7 ± 0.38c 23.9 ± 0.51b 24.4 ± 0.32ab 24.7 ± 0.47a 24.9 ± 0.37a
Ash, % 2.2 ± 0.23b 2.5 ± 0.21ab 2.5 ± 0.21a 2.5 ± 0.33a 2.5 ± 0.39a
Lactose, % 2.3 ± 0.33b 2.4 ± 0.23a 2.4 ± 0.15a 2.4 ± 0.23a 2.3 ± 0.23ab
Moisture/Protein ratio 3.1 ± 0.06a 2.4 ± 0.06b 2.4 ± 0.10b 2.3 ± 0.09bc 2.3 ± 0.11c
Calorie (kcal) 287.3 ± 1.24a 236.2 ± 0.79b 223.9 ± 0.86c 222.1 ± 0.86c 220.1 ± 0.86c
Titratable acidity, % lactic acid 0.23 ± 0.02 0.24 ± 0.01 0.23 ± 0.04 0.23 ± 0.01 0.24 ± 0.03
pH 5.5 ± 0.08 5. 5 ± 0.07 5. 5 ± 0.06 5.5 ± 0.05 5.5 ± 0.04
Frying loss, % 14.2 ± 0.35a 13.0 ± 0.18b 13.1 ± 0.12b 13.1 ± 0.21b 13.2 ± 0.27b
Yield, % 21.0 ± 0.76a 19.0 ± 0.74c 19.5 ± 0.61b 20.3 ± 0.48a 20.5 ± 0.36a
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Means with different superscripts in the same row differ significantly (p ≤ 0.05) (n = 6)

Protein and ash contents of T1, T2, T3, and T4 were higher (p ≤ 0.05) than TC due to increase in SNF content as well as incorporation of higher SPI levels. The moisture protein ratio was higher (p ≤ 0.05) in TC than in T1, T2, T3, and T4. Moisture content in T1, T2, T3, and T4 was higher (p ≤ 0.05) than in TC. Thus moisture and protein contents increased with decrease in fat content of paneer. Similar findings were reported in paneer by Ashraf Pal and Yadav (1992) and Singh and Kanawjia (1988). Higher fat in milk results in lower moisture retention in the final product of paneer. The titratable acidity and pH showed non significant difference for different samples. The paneer yields in T1-T4 were comparable to TC. Lactose content was in the range of 2.3–2.4% in all samples. Similar findings were reported in paneer by Singh and Kanawjia (1988). The calorie content was lower (p ≤ 0.05) in SLFP than in HFP. The frying losses were lower with the decrease of paneer fat content (Table 1).

Sensory appearance and colour scores were lower (p ≤ 0.05) for SLFP than for HFP and the values decreased with increase in SPI levels (Table 2). Up to 0.2% SPI (T2) level low fat paneer did not affect the flavour scores, however beany flavour was perceptible for paneer beyond this level. Fortification with CaCl2 improves mouth feel and appearance (FAO 1995). In 0.3% SPI (T4), texture and juiciness were decreasing, which might be due to increased levels of protein content, however there was no significant difference as compared to T3. Texture, juiciness and overall acceptability scores were higher (p ≤ 0.05) for T3 than for T1, but lower as compared to TC. Functionality of SPI is related to surface-active properties, fat, solubility, gelation, emulsification, dispersibility and viscosity (Ortheofer 1978; Richert and Kolar 1987; SPC 1987; SANA 2004). According to Wilkens et al. (1967), heat denaturation of lipoxygenase reduces beany flavour in soy products.

Table 2.

Effect of soy protein isolate (SPI) incorporation on instrumental texture, colour and sensory quality of low fat paneer

Parameters High fat paneer (TC) SPI level, %
0 (T1) 0.1 (T2) 0.2% (T3) 0.3% (T4)
Textural quality 4.9 ± 0.17c
 Firmness, N 4.5 ± 0.36d 5.2 ± 0.34a 5.1 ± 0.51b 4.9 ± 0.17c
 Gumminess, N mJ/mJ 2.2 ± 0.33c 2.7 ± 0.16a 2.6 ± 0.43b 2.6 ± 0.24b 2.6 ± 0.23b
 Springiness, mm/mm 0.9 ± 0.13a 0.9 ± 0.11b 0.9 ± 0.19b 0.9 ± 0.11b 0.9 ± 0.17b
 Resilience, mJ/mJ 0.6 ± 0.17a 0.6 ± 0.18a 0.6 ± 0.14a 0.6 ± 0.17a 0.6 ± 0.16a
 Chewiness, N mm 2.2 ± 0.18d 2.5 ± 0.12a 2.4 ± 0.21b 2.3 ± 0.11c 2.4 ± 0.23b
 Cohesiveness, mJ/mJ 0.5 ± 0.14a 0.5 ± 0.23a 0.5 ± 0.11a 0.5 ± 0.25a 0.5 ± 0.23a
Hunter colour 88.9 ± 1.43c
 L 90.4 ± 1.35a 89.9 ± 1.46a 89.6 ± 0.12a 89.1 ± 1.43b
 a −1.3 ± 0.18c −1.3 ± 0.22c −1.1 ± 0.32b −1.0 ± 0.17a −1.0 ± 0.17a
 b 9.6 ± 0.29d 10.3 ± 0.22c 10.7 ± 0.31b 11.1 ± 1.99a 11.3 ± 1.99a
Sensory quality 5.9 ± 0.47d
 Appearance and colour 7.7 ± 0.41a 6.9 ± 0.0.57b 6.7 ± 0.41b 6.1 ± 0.52c
 Flavour 7.4 ± 0.46a 6.3 ± 0.54b 6.2 ± 0.46b 6.1 ± 0.40b 5.9 ± 0.40c
 Texture 7.6 ± 0.49a 5.3 ± 0.63d 5.8 ± 0.49c 6.4 ± 0.43b 6.1 ± 0.33b
 Juiciness 7.3 ± 0.48a 5.2 ± 0.84d 5.4 ± 0.48c 5.9 ± 0.43b 5.8 ± 0.56b
 Overall acceptability 7.4 ± 0.40a 5.7 ± 0.60d 6.0 ± 0.40c 6.4 ± 0.42b 6.1 ± 0.22c
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Means with different superscripts in the same row differ significantly (p ≤ 0.05)(n = 6)

Texture profile of paneer

Firmness of paneer was higher (p ≤ 0.05) in T1 than in T2, T3, T4 and TC (Table 2). Similar results were reported in paneer by Chawla et al. (1985) and Kanawjia and Rizvi (2003). Nana et al. (1995) reported that higher protein content increased hardness and reverse is true with increased level of moisture, fat, and salt content. Gumminess of T1 was higher (p ≤ 0.05) than TC. Springiness value for TC (0.98 mm/mm) was higher (p ≤ 0.05) compared with SPI samples (0.91–0.92 mm/mm). This may be attributed to binding characteristics of SPI causing the formation of a gel matrix which in turn results in a more stable product (El-Nagar et al. 2002). There is no significant difference in resilience and cohesiveness of TC and SPI samples. Chewiness of SPI samples were higher (p ≤ 0.05) compared to TC. The chewiness was marginally higher with lower fat content in paneer. These results correlated with Nurcan and Mustafa (2004).

Colour profile analysis

There was a decreasing trend for L value. L value is directly proportional to fat content of paneer, which may be due to light scattering of fat particles (Table 2). The a and b values of SPI samples were higher than control. The SPI incorporation would have increased the amine compounds that react with aldehydes during Maillard reaction to form dark pigments (melanoidins) (Akesowan 2009). Values for a, which signify red (+) and green (−) and b, which signify yellow (+) and blue (−), increased with increasing levels of SPI incorporation, demonstrating that added SPI samples were more green and yellow coloured. This could be attributable to the colour difference between control milk (white colour) and SPI (light brown colour).

Conclusion

Low fat paneer (12.7% fat) containing 0.2% SPI level (T3) using 0.2% CaCl2 as a coagulant was superior to other levels tested. Addition of higher level than 0.2% of SPI imparted beany flavour to the final product. Instrumental firmness, gumminess, and chewiness values of SPI samples was higher than control (Tc). Springiness values showed decreasing trend with incorporation of SPI. There was no significant difference in cohesiveness and resilience of high fat paneer with SPI enriched low fat paneer. The Hunter colour L value decreased with increase of a and b values of paneer for increased SPI levels incorporations.

References

  1. Akesowan A. Influence of soy protein isolate on physical and sensory properties of ice cream. Thai J Agric Sci. 2009;42(1):1–6. [Google Scholar]
  2. Official methods of analysis. 16. Washington: Association of Official Analytical Chemists; 1995. [Google Scholar]
  3. Ashraf Pal M, Yadav PL. Effect of fat level on the quality of paneer from various blends of buffalo and cow milk. Ind J Dairy Sci. 1992;45:554–560. [Google Scholar]
  4. Chawla AK, Singh S, Kanawjia SK. Development of low fat paneer. Ind J Dairy Sci. 1985;38:280–283. [Google Scholar]
  5. Chawla AK, Singh S, Kanawjia SK. Effect of fat level, additives and process modifications on composition and quality of paneer and whey. Asian J Dairy Res. 1987;6:87–92. [Google Scholar]
  6. El-Nagar G, Clowes G, Tudorica CM, Kuri V, Brennan CS. Rheological quality and stability of yog-ice cream with added inulin. Int J Dairy Technol. 2002;55:89–93. doi: 10.1046/j.1471-0307.2002.00042.x. [DOI] [Google Scholar]
  7. FAO (1995) Micronutrient fortification of food technology and quality control. Technical consultation on food fortification. Rome, Italy, 20–23 November, http://www.fao.org/docrep/W2840E/w2840e0b.htm dated 07 December 2009
  8. Specifications for condensed milks. New Delhi: Bureau of Indian Standards; 1973. [Google Scholar]
  9. Handbook of food analysis. Dairy products. Part X1. New Delhi: Bureau of Indian Standards; 1981. [Google Scholar]
  10. Kanawjia SK, Rizvi SS. Development of paneer from MF retentate. Ind J Dairy Sci. 2003;56:203–207. [Google Scholar]
  11. Kanawjia SK, Roy SK, Singh S. Paneer technology and diversification. Indian Dairym. 1990;19:390–393. [Google Scholar]
  12. Keeton JT. Effect of fat and NaCl/phosphate levels on the chemical and sensory properties of pork patties. J Food Sci. 1983;48:878–881. doi: 10.1111/j.1365-2621.1983.tb14921.x. [DOI] [Google Scholar]
  13. Nana Y, Farkye BB, Rossi NOR. Sensory and textural properties of Quesco-Blanco-type cheese influenced by acid type. J Dairy Sci. 1995;78:1649–1656. doi: 10.3168/jds.S0022-0302(95)76789-3. [DOI] [Google Scholar]
  14. Nurcan K, Mustafa M. Textural, melting and sensory properties of low-fat fresh kashar cheeses produced by using fat replacers. Int Dairy J. 2004;14:365–373. doi: 10.1016/j.idairyj.2003.08.006. [DOI] [Google Scholar]
  15. O’keeffe RB, Fox PF, Daly C. Contribution of rennet and starter proteases to proteolysis in cheddar cheese. J Dairy Res. 1976;43:97–101. doi: 10.1017/S0022029900015636. [DOI] [Google Scholar]
  16. Ortheofer FT. Processing and utilization. In: Norman AG, editor. Soybean physiology, agronomy and utilization. New York: Academic Press Inc; 1978. pp. 219–246. [Google Scholar]
  17. Richert SJ, Kolar CW. Value of isolated soy protein in food products. In: Dupont J, Osmna EM, editors. Cereals and legumes in the food supply. Ames: Iowa State University Press; 1987. pp. 73–90. [Google Scholar]
  18. SANA (2004) Soy protein isolate. Soyfoods Association of North America. Gain report accessed at www.soyfoods.org. (Accession date August 10, 2007)
  19. Singh S, Kanawjia SK. Development of manufacturing technique for paneer from cow milk. Ind J Dairy Sci. 1988;41:322–325. [Google Scholar]
  20. Singh S, Kanawjia SK. Manufacturing technique for paner from recombined milk using cow skim milk powder and butter oil. Ind J Dairy Sci. 1991;44:76–79. [Google Scholar]
  21. Snedecor GW, Cochran WG. Statistical methods. 8. New Delhi: Oxford and IBH public Co.; 1994. [Google Scholar]
  22. Soy protein products: characteristics, nutritional aspects and utilization. Washington: Soy Protein Council; 1987. [Google Scholar]
  23. Wilkens WF, Mattick LR, Hand DB. Effect of processing methods on oxidative off-flavours of soybean milk. Food Technol. 1967;21:1630. [Google Scholar]

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