Document Type
Article
Publication Date
8-27-2008
Journal or Book Title
Journal of Agricultural and Food Chemistry
Volume
56
Issue
16
First Page
7146
Last Page
7150
DOI
10.1021/jf801136n
Abstract
The Kunitz trypsin inhibitor (KTI) and the Bowman−Birk inhibitor (BBI) of trypsin and chymotrypsin contain disulfide bonds. Glycinin, the major storage protein in soybeans also contains disulfide bonds. Treatment of soy white flour with a NADP−thioredoxin system (NTS) effectively reduced disulfide bonds in soy flour and increased protein digestibility by trypsin and pancreatin as measured by the pH stat method. Treatment of soy flour with NTS increased the digestibility compared to soy white flour by 29.3 and 60.6% for trypsin and pancreatin, respectively. NTS-treated soy flour had similar digestibility by trypsin to autoclaved soy flour and casein, but digestibility by pancreatin was less than autoclaved soy flour and casein. The degree of reduction by NTS was highly correlated to the degree of hydrolysis (DH) by trypsin (R2 = 0.93) and pancreatin (R2 = 0.99). The DH of NTS-treated soy flour by trypsin is reflective of both inactivation of trypsin inhibitors and overall protein digestibility while pancreatin hydrolysis is reflective of only overall protein digestibility.
Copyright Owner
2008
Copyright Date
American Chemical Society
Language
en
File Format
application/pdf
Recommended Citation
Faris, Richard J.; Wang, Hui; and Wang, Tong, "Improving Digestibility of Soy Flour by Reducing Disulfide Bonds with Thioredoxin" (2008). Food Science and Human Nutrition Publications. 3.
https://lib.dr.iastate.edu/fshn_ag_pubs/3
Comments
Posted with permission from Journal of Agricultural and Food Chemistry, 56, no. 16 (2008): 7146–7150, doi: 10.1021/jf801136n. Copyright 2008 American Chemical Society.