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Use of the pH Stat to Evaluate Trypsin Inhibitor and Tryptic Proteolysis of Soy Flours
Author(s) -
HILL BRYAN S.,
SNYDER HARRY E.,
WIESE KURT L.
Publication year - 1982
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1982.tb12935.x
Subject(s) - proteolysis , trypsin , chemistry , soy protein , trypsin inhibitor , hydrolysis , chromatography , biochemistry , enzyme , food science
Heated soy flours have been analyzed by the pH stat successfully for tryptic proteolysis and for residual trypsin inhibitor in previous studies. Unheated soy flours give a sudden release of hydrogen ion followed by a constantly decreasing proteolysis rate and consequently are difficult to analyze. We have found that by adjusting the pH of the trypsin preparation to 9 (the pH of the analysis) the pH stat method measured proteolysis and trypsin inhibitor in unheated soy flours. The unheated soy protein was hydrolyzed at 40% of the rate of heated soy protein and contained 68 mg/g of Kunitz trypsin inhibitor equivalents.