Cereal Chem 40:531 - 538.  |  VIEW ARTICLE

Feeding Studies on Soybeans. Growth and Pancreatic Hypertrophy in Rats Fed Soybean Meal Fractions.

J. J. Rackis, A. K. Smith, A. M. Nash, D. J. Robbins, and A. N. Booth. Copyright 1963 by the American Association of Cereal Chemists, Inc. 

Rats were fed raw or toasted soybean meal, acid-precipitated protein, whey solids, and whey protein. Weight gains, protein efficiencies, and pancreas weights were determined. As measured chemically, all raw products contained widely different levels of trypsin inbibitor activity; and for some fractions there was no direct relationship between trypsin inhibitor activity, growth inhibition, and pancreatic hypertrophy. Autoclaving of the meal and residue significantly increased weight gains and protein efficiency values, and decreased pancreatic hypertrophy. The residue contains a pancreatic hypertrophic factor that is relatively heat-stable. Autoclaving had no effect on the nutritive value of the acid-precipitated protein. Only slight pancreatic hypertrophy occurred in rats fed raw acid-precipitated protein. Poor growth, low protein efficiency, and pancreatic hypertrophy occurred with rats fed casein diets containing raw soybean whey solids and whey protein. Trypsin inhibitor activity of these diets was very high. Better weight gains and higher protein efficiency values were obtained with casein supplemented with toasted whey protein than with casein alone. Significant pancreatic hypertrophy also occurred in rats fed autoclaved whey protain