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Chemical inactivation of soybean protease inhibitors
Author(s) -
Sessa David J.,
Nelsen Terry C.
Publication year - 1991
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02663814
Subject(s) - chemistry , protease , kunitz sti protease inhibitor , histidine , biochemistry , glutamine , asparagine , trypsin , methionine , soy protein , tyrosine , protease inhibitor (pharmacology) , trypsin inhibitor , amino acid , enzyme , food science , biology , human immunodeficiency virus (hiv) , antiretroviral therapy , viral load , immunology
This study aimed to optimize chemical treatments to destroy Kunitz (KTI) and Bowman‐ Birk (BBI) type protease inhibitors in model systems, and to destroy total trypsin inhibitor activity in soy flour. Time, temperature, and reagent concentration were studied and 40 to more than 85% inactivation of KTI and BBI were observed by treatment with 0.6 mM Na 2 S 2 O 5 ,10 mM ascorbic acid + 0.8 mM CuSO 4 or 20 mM H 2 O 2 + 0.8 mM CuSO 4 at 65‐ 90°C for 0.5‐ 1 hr. Upon treatment with Na 2 S 2 O 5 , KTI and BBI amino acid composition had no significant change. In contrast, AH + CU 2+ treatment of both KTI and BBI markedly increased aspartic acid + asparagine and glutamic acid + glutamine contents, and significantly decreased histidine, tyrosine, and methionine. With soy flour, only Na 2 S 2 O 5 effectively inactivated both protease inhibitors. Steeping soybean flour in 50 mM Na 2 S 2 O 5 at 65°C for 1 hr inactivated about 98% BBI and 95% KTI. The information conveyed is basic to developing chemical methodology needed to inactivate both KTI and BBI protease inhibitors in soy protein products.