Abstract: This invention relates to methods for the large-scale enzymatic deamidation of foot proteins. Deamidating enzymes such as peptidoglutaminase are immobilized using a spiral membrane having a molecular weight cut-off, from about 3 to about 50 kd. The methods minimize loss of the enzymatic activity for subsequent reuse of the enzyme as well as increase deamidation product yield.

Abstract: Deamidation of food proteins by Bacillus circulans peptidoglutaminase was impaired by the large molecular size and unique conformation of these proteins. The limited ability of peptidoglutaminase to deamidate food proteins was increased dramatically by protein hydrolysis and altering protein conformation, principally by moist heat. A method to prepare enzymatically deamidated food proteins with a wide range of protein deamidation was developed. Enzymatic deamidation of proteins improved their functional properties especially in the mild acidic pH region (e.g., 4-6).