Evaluation of Changes in Chemical and Functional Properties during Production of Soy Protein Concentrates from Industrial Soy Flours

مجله پژوهشهای علوم و صنایع غذایی ایران

Article 3, Volume 8, Issue 1 - Serial Number 19, April 2012   

Document Type: Research Article

DOI: 10.22067/ifstrj.v8i1.14385

Authors

Maryam Ravaghi^{* 1}; Mostafa Mazaheri Tehrani²; Ahmad Asoodeh³

¹Agricultural Engineering Research Department, Khuzestan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization )AREEO(, Ahvaz, Iran

²Department of Food Science and Technology, Faculty of Agriculture, Ferdowsi university of Mashhad,

³Department of Food Science and Technology, Ferdowsi University of Mashhad, Mashhad, Iran.

Abstract

Soy protein concentrate (SPC) is a functional and nutritional product which is produced under conditions where soy proteins are immobilized in soy flour and soluble carbohydrates are removed. In this study, four different soy flours including defatted soy flour (fat content 3.67, PDI 55.10), defatted and toasted soy flour (fat content 3.78, PDI 10.72), low fat soy flour (fat content 14.34, PDI 32.71), and whole soy flour (fat content 22.08, PDI 28.72) and two washing methods including alcohol washing and acid washing were used to produce SPC Then yield, changes in chemical and functional properties including PDI, dispersible solids, water holding and fat binding capacity, emulsifying and foaming properties were determined. The results showed that SPC from whole soy flour had higher yield and higher increase in fat content but presence of fat reduced protein concentration. Acid washing had lower production yield than alcohol washing due to better removalg of soluble carbohydrates but it increased fat and protein content. Functional properties of SPC from defatted soy flour was changed significantly during its process while fat content or heat denaturation occurred during toasting diminished its effect except for emulsification stability. During the process, water holding capacity increased specially in products with higher amounts of fat content. Although most of PDI changes arose from drying step, but the effect of processing on emulsification and foaming properties was much higher than drying.

Keywords

Chemical properties; Functional properties; PDI; Soy protein concentrate; Soy flour

References

شاهکار، غ.، 1380، طرح و تحلیل آزمایشها، مرکز نشر دانشگاهی، تهران، 556-539.

AACC, 1983, Approved Method of American Association of Cereal Chemistry.

AOAC, 2002, Official Methods of Analysis from Official Analytical Chemists.

Fenema, O. R., 1996, Food chemistry, Marcel Dekker Inc, New York, 383-385.

Heywood, A.A., Myers, D.J., Baiely, T.B. and Johnson, L.A., 2002, Functional properties of low fat soy flour produced by an extrusion-expelling system. Journal of American Oil Chemist' Society, 79(12): 1249-1253.

Kinsella, J., 1979, Functional properties of soy proteins. Journal of American Oil Chemist' Society, 56, 242-258.

Lin, M.J.Y., Humbert, E.S. and Sosulski, F.W., 1974, Certain functional properties of sunflower meal products. Journal of Food Science, 39, 368–370.

Liu, K., 2004, Soybean as functional foods and ingredients. American Oil Chemist' Society press, U.S.A.

Meyer, E.W., 1971, Oilseed protein concentrate and isolate. Journal of the American Oil Chemists' Society, 48(9), 484-488.

Morr, C.V., 1990, Current status of soy protein functionality in food systems. Journal of American Oil Chemist' Society, 67(5), 265-271.

Nelson, A.I., Wijeratne, W.B., Yeh, S.W., Wei, T.M. and Wei, L.S., 1987, Dry extrusion as an aid to mechanical expelling of oil from soybean. Journal of the American Oil Chemists' Society, 64(9), 1341-1347.

Pearce, K. N. and Kinsella, J. E., 1978, Emulsifying properties of proteins: evaluation of a turbidimetric technique. Journal of Agricultural and Food Chemistry, 26(3), 716–723.

Pringle, W., 1974, Full fat soy flour. Journal of American Oil Chemist' Society, 51, 74-76.

Singh, P., Kumar, R., Sabapathy, S.N., and Bawa, S., 2008, Functional and edible uses of soy protein products. Comprehensive Reviews in Food Science and Food Safety, 7(1), 14-28.

Smith, K. J., and Huyser, V., 1987, World distribution and significance of soybean, In: Wilcox, J.R., ed., Soybeans: improvement, production and uses, 2nd ed. American Society of Agronomy Incorporation, USA.

Statistical Analysis System, 2002-2003, SAS Institute, Cary, North Carolina, USA.

Sugarman, N., 1956, Process for simultaneously extracting oil and protein from oleaginous materials, U.S. Patent. 4,307,014.

Wang, H., Johnson, L.A., and Wang, T., 2004, Preparation of soy protein concentrate and isolate from extruded-expelled soybean meals. Journal of the American Oil Chemists' Society, 81, 713-717.