Preparation and Functional Evaluation of Chitosan-EGCG Conjugates

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 H-1-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. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39732.