Preparation of glycosylated zein and retarding effect on lipid oxidation of ground pork.

The focus of the present work was to investigate the glycosylation of zein, partial properties of the glycosylated zein (GZ) and its retarding effect on lipid oxidation of ground pork. Zein was glycosylated with chitosan (MW 1500Da) by microbial transglutaminase, the reaction was verified by FT-IR. Under the optimized conditions, 97.48mg of glucosamine was covalently conjugated to 1g of zein, determined by HPLC. The solubility and the surface hydrophobicity of GZ were significantly improved. In vitro studies of GZ showed a dose-dependent scavenging activity against free radicals of DPPH, superoxide and hydroxyl radical, and the EC50 value for DPPH radical was 1.99μg TE/mg protein. In addition, reducing power and Fe(2+)-chelating capacity of it were 16.60 and 12.96μg TE/mg protein, respectively. GZ resulted in low levels of thiobarbituric acid-reactive substances and peroxide value of ground pork. These results suggest that GZ is a potential natural antioxidant.