Cereal Chem 53:656 - 670.  |  VIEW ARTICLE
Heat-Moisture Effects on Wheat Flour. II. An Evaluation Study of Heat-Processing Effects on Flour Proteins by Digestive Enzymes---Pepsin, Trypsin, and Trypsin-Carboxypeptidase.

B. L. Hansen and P. Johnson. Copyright 1976 by the American Association of Cereal Chemists, Inc. 

Wheat flour (hard red winter, 1st clears) was processed in a reversed heat exchanger designed to control processing parameters of temperature (108, 150, and 174 C), moisture (13-33%), and time (2,5, and 10 min). Enzymatic methods were used to measure in vitro digestibility of thermally processed flour proteins. Peptide bonds of processed flour proteins were less accessible to pepsin and trypsin attack than the bonds of unprocessed flour proteins. The highest pepsin and trypsin digestion rates for the processed flour proteins were for flour processed with a 13% moisture content at 108 C for 2 min; more severe processing resulted in a progressive reduction in digestion rates. Lysine availability was measured by trypsin-carboxypeptidase- B digestion of heat-processed flour proteins. Lysine availability of processed proteins (150, 174 C) was decreased.