SYNTHESIS, CHARACTERISATION AND APPLICATION OF GELATIN-CHITOSAN BLEND FILMS FOR FRUIT PRESERVATION

摘要

In this study, gelatin-chitosan (Gel-Cs) blend films were prepared at three volume per volume ratios (Gel:Cs) namely 75:25, 50:50 and 25:75. The gelatin-chitosan blend films were applied for the first time to preserve cherry tomatoes (Solanum lycopersicum) and grapes (Vitis vinifera) in a 14-day preservation study. The addition of chitosan has improved the transparency value, tensile strength, percentage elongation at break, water vapour, oxygen permeability and antimicrobial properties of gelatin film. Of blended films studied, 25Gel:75Cs film exhibited the best functional and mechanical properties. The tensile strength and elongation at break values of 25Gel:75Cs film showed a significant increased by 26% and 63%, respectively. The presence of chitosan has enhanced the ability of gelatin film to inhibit two common food pathogenic microorganisms, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Results from preservation study suggest that the gelatin-chitosan blend films were successfully able to control the percentage weight loss and browning index of both commodities. The performance of gelatin-chitosan blend films to prolong the shelf life and maintain the quality of perishable agricultural products was comparable to that of commercial cling film. Overall, blending of gelatin with chitosan produced environmental friendly films with improved key physicochemical and functional properties for fruit preservation.