Effect of Maillard reaction products on the physical and antimicrobial properties of edible films based on ε-polylysine and chitosan

BACKGROUND: Edible films based on Maillard reaction products (MRPs) of epsilon-polylysine and chitosan, without the use of any plasticiser, were prepared by solution casting. The effect of Maillard reaction parameters (reaction time and the ratio of polylysine/chitosan) of epsilon-polylysine and chitosan on the structure, moisture content, water solubility, total colour difference and mechanical properties of edible films formed by MRPs were systematically evaluated. RESULTS: Scanning electron microscopy confirmed that edible films prepared by the MRPs of epsilon-polylysine and chitosan through the Maillard reaction exhibited a more compact and dense structure than those from the mixture of biopolymers without the presence of MRPs. The tensile strength and % elongation values of films from the mixture were decreased significantly with the rise of epsilon-polylysine (P < 0.05). The moisture content of the films was not significantly affected by Maillard reaction, whereas water solubility was decreased and total colour difference was increased significantly (P < 0.05) with the extension of Maillard reaction time. In addition, antimicrobial activity of chitosan films against E. coli and S. aureus. could be achieved by incorporating epsilon-polylysine into chitosan. CONCLUSION: These films can ensure food quality and safety, especially for coating highly perishable foods, such as meat products. (C) 2014 Society of Chemical Industry