Improvement of digestibility, reduction in allergenicity, and induction of oral tolerance of wheat gliadin by deamidation.

Wheat gliadin was deamidated by using a cation-exchange resin in the presence or absence of added cysteine, with the change in digestibility being measured. The allergenicity of the gliadin was evaluated by using sera from patients RAST-positive to wheat. Gliadin-specific IgE was measured after the gliadin had been orally administered to rats.

Effect of phytate-removal and deamidation of soybean proteins on calcium absorption in the in situ rats.

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.

Enhanced calcium absorption in the small intestine by a phytate-removed deamidated soybean globulin preparation.

Soybean globulins were deamidated after removing phytate using ion-exchange resins, and then hydrolyzed by digestive enzymes. The phytate-removed deamidated soybean globulins (PrDS) retained high calcium-binding ability even after the hydrolysis by digestive enzymes. PrDS and its hydrolysates enhanced calcium absorption from the small intestine when injected into the small intestine together with a calcium solution.