Method for modification of rice protein and oryzenin with protein glutaminase

Abstract

The invention relates to a method for modification of rice protein and oryzenin with protein glutaminase, which comprises the following steps: adding the rice protein or oryzenin into a constant-temperature enzyme reactor with phosphate buffer solution while stirring to obtain protein dispersion solution with a certain substrate concentration; adding protein glutaminase to obtain a system with a certain proportion of enzyme and substrate, wherein the temperature of enzymatic reaction is 36-38 DEG C, the time of the enzymatic reaction is 0.1-48 hour(s), and the pH value of the enzymatic reaction is maintained 7.0; adding dialysis solution, i.e. acetic acid solution of 0.10mol / L, wherein the dialysis time is about 8 hours; and carrying out vacuum freeze-drying, thereby obtaining the product. The invention can improve the protein solubility of the rice protein or the oryzenin, and can also enhance the emulsification, foaming performance, gelation and other functional properties of the rice protein or the oryzenin.

Description

technical field [0001] The invention relates to a method for modifying rice protein or rice glutenin by protein glutaminase. Background technique [0002] The protein content in rice is 8%-13%. Studies have found that rice protein is one of the highest nutritional value among cereal proteins. It has the characteristics of colorless, mild taste, rich in essential amino acids, hypoallergenic and low cholesterol. However, the high content of glutamine and asparagine in the protein causes the protein to aggregate and precipitate through hydrogen bonding, resulting in low solubility, which limits its application in liquid food and beverages; low solubility will also affect protein Other functional properties such as foaming, emulsifying and gelling properties. [0003] The development of the food industry requires protein ingredients with outstanding functional properties. There are two ways to solve this problem: developing protein resources and modifying existing proteins. Th...

AI Technical Summary

Problems solved by technology

The modification methods for rice protein are mainly acid modification and some protease modification. It has been found that acid deamidation can significantly improve the solubility of wheat gluten and zein; Amides also significantly improve their solubility, but hydrolysis of protein peptide chains and degradation of other amino acid residues are inevitable during acid treatment at high temperatures

Compared with acid treatment, the reaction conditions of enzymatic deamidation are mild and have higher specificity. It has been reported that transglutaminase, protease and peptide glutaminase can be applied to protein deamidation, but glutamine Aminotransferases and proteases may cause hydrolysis or cross-linking of peptide chains, resulting in undesirable flavors, and racemization of amino acids, etc., while the substrates of peptide glutaminase are limited to short peptides