Affiliations: Department of Agricultural and Biological Chemistry,
College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa-shi
252-8510, Japan. Tel./Fax: +81 466 84 3946; E-mail:
kumagai@brs.nihon-u.ac.jp | Department of Food Science and Nutrition, Kyoritsu
Women's University, 1-710 Motohachioji, Hachioji-shi, Tokyo 193-8501,
Japan
Note: [] Corresponding author
Abstract: Soybean proteins were deamidated by cation-exchange resins after
phytate, the inhibitor for calcium absorption from the small intestine, was
removed in order to provide the enhancement function of calcium absorption to
soybean proteins. About 92% of the phosphorus was removed from the soybean
proteins by anion-exchange-resin treatment, indicating that most of the phytate
was removed. About 70% of the acid amide was deamidated by
cation-exchange-resin treatment, and phytate-removed and deamidated soybean
proteins (PrDS) having high calcium binding properties were obtained. PrDS were
hydrolyzed by digestive enzymes and their calcium-binding properties and the
enhancement function of the calcium absorption from the small intestine of rats
were examined. As a result, PrDS retained their high calcium binding properties
even after hydrolysis by digestive enzymes. In situ experiments showed
that PrDS and their hydrolysates enhanced the calcium absorption from the
intestine.
