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Changes in the nutritive value of soy protein concentrate during autoclaving

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Soy protein concentrate (Promosoy R Plus) was mixed with water to form a thick paste and autoclaved at 121°C for 10 min, 30 min, 2 h, or 4 h. Unautoclaved SPC served as a control. Nitrogen solubility measurements and SDS-PAGE analysis indicated that autoclaving resulted in the formation of soy protein aggregates, with a MW of ∼1 million daltons, held together by non-covalent and disulfide bonds. The 10 min, 30 min, 2 h, and 4 h SPC samples contained 6, 20, 27 and 39% less cysteine, respectively, than the SPC control. No significant differences were found in the PERs, 2.6-2-7, of a casein control, unautoclaved SPC control and 10 min and 30 min autoclaved samples. PERs of the 2 h and 4 h autoclaved samples, 2.0 and 1.9 respectively, were significantly lower than the other four diets. No significant differences were found in the apparent digestibility of the 10 min, 30 min, and 2 h autoclaved samples; the 4 h autoclaved sample however was significantly less digestible. Decreased PERs of autoclaved SPC samples were likely due to (1) crysteine destruction, (2) decreased protein digestibility, and (3) decreased food intake.

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  1. AOAC (1980) Officical Methods of Analysis, 13th edn. Washington, DC: Association of Official Analytical Chemists, pp. 774

  2. Badenhop AF, Hackler LR (1971) Protein quality of dry roasted soybeans: Amino acid composition and protein efficiency ratio. J Food Sci 36: 1–4

  3. Cheftel JC, Cuq JL, Lorient D (1985) Amino acids, peptides and proteins. In: Fennema OW (ed.), Food Chemistry. New York: Marcel Dekker Inc., pp. 335.

  4. Chiang JPC, Sternberg M (1974) Physical and chemical changes in spun soy protein fibers during storage. Cereal Chem 51: 465–471

  5. Cumming DB, Stanley DW, DeMan JM (1973) Fate of water soluble soy protein during thermoplastic extrusion. J Food Sci 38: 320–323

  6. Damodaran S, Kinsella JE (1982) Effect of conglycinin on the thermal aggregation of glycinin. J. Agric Food Chem 30: 812–817

  7. Fling SP, Gregerson DS (1986) Peptide and protein molecular weight determination by electrophoresis using a high molarity Tris buffer system without urea. Anal Biochem 155:83–88

  8. Fukushima D (1968) Internal structure of 7S and 11S globulin molecules in soybean proteins. Cerel Chem 45: 203–224

  9. German B, Damodaran S, Kinsella JE (1982) Thermal dissociation and association behaviour of soy proteins. J Agric Food Chem 30: 807–811

  10. Hager DF (1984) Effects of extrusion upon soy concentrate solubility. J Agric Food Chem 32: 293–296

  11. Harper RG (1989) Technical service bulletin, product information sheet: promosoy-100, Central Soya, Forst Wayne, IN

  12. Harte RA, Traver JJ, Sarich P (1947) Protein assay by rat growth; A comparison of (A) litter mates vs randomly selected males and (B) moderate restriction in food intake vs ad libitum feeding. J Nutr 34: 363–372

  13. Hashizume K, Watanabe T (1979) Influence of heating temperature on conformational changes in soybean protein. Agric Biol Chem 43: 683–690

  14. Lehninger AL (1978) Biochemistry, 2nd. edn. New York: Worth Publishers, Inc., pp. 698

  15. Longenecker JB, Martin WH, Sarett HP (1964) Improvement in the protein efficiency of soybean concentrates and isolates by heat treatment. J Agric Food Chem 12: 411–412

  16. An H, Marshall MR, Otwell WS, Wei CI (1988) Electrophoretic identification of raw and cooked shrimp using various protein extraction systems. J Food Sci 53: 313–318

  17. Glimp HA, Karr MR, Little CO, Woolfolk PG, Mitchell GE Jr, Hudson LW (1967) Effects of reducing soybean protein solubility by dry heat on the protein utilization of young lambs. J Anim Sci 26: 858–861

  18. Mitchell HH, Beadles JR (1930) The paired feeding method in nutrition experiments and its application to the problem of cysteine deficiencies in food protein. J Nutr 2: 225–243

  19. Moore S (1963) On determination of cystine as cysteic acid. J Biol Chem 238: 235–237

  20. Pellet PL, Matthew SP (1986) Protein quality of homemade weaning food mixtures: 2. Amino acid composition versus biological methods. Ecology Food Nutr 19: 41–49

  21. Rios-Iriarte BJR, Barnes RH (1966) The effect of overheating on certain nutritional properties of the protein of soybeans. Food Technol 20: 835–838

  22. Schingoethe DJ, Ahrar M (1979) Protein solubility, amino acid composition and biological value of regular and heat-treated soybean and sunflower meals. J Dairy Sci 62: 935–931

  23. Saio K, Sato I, Watanabe T (1974) Food use of soybean 7S and 11S proteins. High temperature expansion characteristics of gels. J Food Sci 39: 777–782

  24. Saoi K, Kajikawa M, Watanabe T (1971) Food processing characteristics of soybean proteins. Part II. Effect of sulfhydryl groups and physical properties of tofu-gel. Agric Biol Chem 238: 235–237

  25. Saoi K, Terashiam M, Watanabe T (1975) Food use of soybean 7S and 11S proteins. Heat denaturation of soybean proteins at high temperatures. J Food Sci 40: 537–540

  26. Taira H, Koyanagi T, Takanohashi T, Oikawa K (1969) Studies on amino acid contents of processed soybean. Part XI. Evaluation of nutritional losses of overheated defatted soybean flour. Agr Biol Chem 33: 1387–1398

  27. Utsumi S, Kinsella JE (1985) Structure-function relationships in food proteins: subunit interactions in heat induced gelation of 7S, 11S and soy isolate proteins. J Agric Food Chem 33: 297–303

  28. Utsumi S, Nakamura T, Mori T (1983) Role of constitutent subunits n the formation and properties of heat induced gels from 11S globulins. J Agric Food Chem 31: 503–506

  29. Wolf WJ, Tamura T (1969) Heat denaturation of soybean 11S protein. Cereal Chem 46: 331–344

  30. Wohlt JE, Sniffen CJ, Hoover WH, Johnson LL, Walker CK (1976) Nitrogen metabolism in wethers as affected in dietary protein solubility and amino acid profile. J Anim Sci 42: 1280–1289

  31. Yamagishi T, Tamarchi F, Shibasaki K (1980) Isolation and partial characterization of heat-denatured products of soybean 11S globulin and their analysis by electrophoresis. Agric Biol Chem 44: 1575–1582

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Correspondence to William E. Barbeau.

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Kim, Y.A., Barbeau, W.E. Changes in the nutritive value of soy protein concentrate during autoclaving. Plant Food Hum Nutr 41, 179–192 (1991).

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Key words

  • soy protein
  • thermal processing
  • protein quality