Preparation and functional evaluation of chitosan‐EGCG conjugates

ABSTRACT Chitosan, as a novel food additive, is proposed to conjugate with EGCG using a free radical grafting procedure. Chitosan is activated by hydroxyl free radicals produced by the redox reaction of hydrogen peroxide and ascorbic acid and subsequently react with EGCG. Chitosan‐EGCG conjugate has demonstrated by UV, FTIR, and 1 H‐NMR spectroscopy and exhibits a dramatical increase in DPPH free radical scavenging activity. In addition, the LC (low‐molecular‐weight chitosan)‐EGCG conjugate is used to prepare O/W emulsion and then monitor the average droplet size, polydispersity index, zeta‐potential and transmission changes during centrifuge process, results show that the conjugate exhibited excellent emulsifying activity and superior emulsifying stability as compared with chitosan. Therefore, LC‐EGCG conjugate could be used as an efficient natural food antioxidant and emulsifier. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 39732.