The influence of soybean genotypes and HTC-processing method on trypsin inhibitor activity of soymilk

Slađana P Stanojević; Miroljub B Barać; Mirjana B Pešić; Biljana V Vucelić-Radović

Slađana P Stanojević Univeristy of Belgrade, Faculty of Agriculture
Miroljub B Barać Univeristy of Belgrade, Faculty of Agriculture
Mirjana B Pešić Univeristy of Belgrade, Faculty of Agriculture
Biljana V Vucelić-Radović Univeristy of Belgrade, Faculty of Agriculture

Abstract

Kunitz (KTI) and Bowman-Birk trypsin inhibitor (BBI) are inhibitors of digestive enzymes in raw soybeans. To improve the nutritional quality of soy foods, trypsin inhibitors (TI) are generally inactivated by heat treatment. Soymilk is a turbid and stable colloidal solution, obtained after thermal treatment of soybean. In this study soymilk was made on the pilot-plant scale from six soybean cultivars by the production method that includes hydrothermal cooking (HTC). This procedure is significantly different from the traditional one. The aim of this study was to assess the influence of a HTC-processing for soymilk production and different soybean genotype on trypsin inhibitors content and activity. Obtained soymilk contained BBI in a trace amounts, in the BBI-polymeric forms. BBI- monomeric forms was not detected. The soymilk of the investigated soybean genotypes had very similar KTI levels (2.34-2.99%). Results suggested that soybean genotype does not have substantial effects on the levels of KTI, as well as on the value of residual trypsin inhibitor activity (rTIA). Total content of TI and rTIA was in strong dependence (r=0.91; p<0.05). HTC-soymilk rTIA was <20% (7.15-19.89%). These results suggested that soymilk obtained by HTC-processing could be applied for human consumption.

Author Biographies

Slađana P Stanojević, Univeristy of Belgrade, Faculty of Agriculture

Institute of Food Technology and Biochemistry, Department of Chemistry and Biochemistry

Miroljub B Barać, Univeristy of Belgrade, Faculty of Agriculture

Institute of Food Technology and Biochemistry, Department of Chemistry and Biochemistry

Mirjana B Pešić, Univeristy of Belgrade, Faculty of Agriculture

Institute of Food Technology and Biochemistry, Department of Chemistry and Biochemistry

Biljana V Vucelić-Radović, Univeristy of Belgrade, Faculty of Agriculture

Institute of Food Technology and Biochemistry, Department of Chemistry and Biochemistry

References

Barac, M., Stanojevic, S. (2005): The effect of microwave roasting on soybean protein composition and components with trypsin inhibitor activity. Acta Aliment. 34:23-31.

Chen, Y.,Ono, T. (2014): Protein particle and soluble protein structure in prepared soymilk. Food Hydrocolloids 39:120-126.

Davis, J. (1964): Disc electrophoresis−II. Method and application tohuman serum proteins. Ann. N.Y. Acad. Sci. 121:404−427.

Fling, S. P., Gregerson, D. S. (1986): Peptide and protein molecular weight determination by electrophoresis using a high-molarity trisbuffer system without urea. Anal. Biochem. 155: 83−88.

Friedman, M., Brandon, L. D. (2001): Nutritional and health benefits of soy protein. J. Agric. Food Chem. 49(3):1069−1086.

Liener, I. E. (1994): Implications of anti-nutritional components in soybean foods. CRC Crit. Rev. Food Sci. Nutr. 34:31−67.

Liu, F., Markakis, P. (1989): An improved colorimetric method for determining antitryptic activity in soybean products. Cereal Chem. 66:415−422.

Ono, T. (2008): The mechanism of soymilk and tofu formation from soybean, and the factors affecting the formation. Nippon Shokuhin Kagaku Kaishi 55(2):39-48.

Pesic, M.B., Vucelic-Radovic, B.V., Barac, M.B., Stanojevic, S.P. (2005): The influence of genotypic variation in protein composition on emulsifying properties of soy proteins. J. Am. Oil Chem.Soc. 82:667-672.

Pesic, B. M., Vucelic-Radovic, V. B., Barac, B. M., Stanojevic, P. S., Nedovic, A. V. (2007): Influence of different genotypes on trypsin inhibitor levels and activity in soybeans. Sensors, 7, 67−74.

Sessa, D.J., Wolf, W.J. (2001): Bowman-Birk inhibitors in soybean seed coats. Ind. Crop. Prod.

Stanojevic, P. S., Barac, B. M., Pesic, B. M., Vucelic-Radovic, V. B. (2011): Assessment of soy genotype and processing method on quality of soybean tofu. J. Agric. Food Chem. 59(13):7368−7376.

Stanojevic, P. S., Barac, B. M., Pesic, B. M., Vucelic-Radovic, V. B. (2012): Composition of proteins in okara as a byproduct in hydrothermal processing of soymilk. J. Agric. Food Chem. 60:922−9228.

Stanojevic, P.S., Barac, B.M., Pesic, B.M., Jankovic, S.V., Vucelic-Radovic, V.B. (2013): Bioactive proteins and energy value of okara as a byproduct in hydrothermal processing of soy milk. J. Agric. Food Chem.61:9210-9219.

Vollmann, J., Grausgruber, H., Wagentristl, H., Wohleser, H., Michele, P. (2003): Trypsin inhibitor activity of soybean as affected by genotype and fertilisation. J. Sci. Food Agric. 83, 1581-1586.

Wang, C., Johnson, A. L., Wilson, A. L. (2003): Calcium coagulation properties of hydrothermally processed soymilk. J. Am. Oil Chem. Soc. 80(12):1225–1229.

Xu, Z., Chen, Y., Zhang, C., Kong, X., Hua, Y. (2012): The heat-induced protein aggregate correlated with trypsin inhibitor inactivation in soymilk processing. Journal of Agricultural and Food Chemistry, 60:8012-8019.