The Study on Chitosan Coating on Poly(Lactic Acid) Film Packaging to Extend Vegetable and Fruit Life

The objective of this work is the study of possibility of extending the life of vegetables and fruits packed with polylactic acid (PLA) film coated with squid chitosan with various contents (0, 1, 3 and 5 phr), acted as an antimicrobial agent and the study of mechanical properties of these films. In the first step, PLA was compounded with 20 percents of glycerol by using a two-roll mill. After that, all compounds were fabricated by blown film extrusion. In next step, the chitosan solutions were prepared in 1 wt% hydrochloric acid solution to coat on one side of PLA film. The last step, the prepared films were examined tensile properties and storage time of 4 types of vegetables and fruits including broccolis, Leb Mue Nang bananas, red grapes and queen tomatoes by packing. The results showed that the tensile strength of PLA films coated with chitosan was closed to that of neat PLA/glycerol film. For spoilage test, it was found that all vegetables and fruits were more shriveled and wilted with more chitosan content through respiration process due to the leakage of chotisan coated PLA film and weight loss of vegetables and fruits., especially for PLA film coated with 5 phr chitosan since more remained acetic acid solvent accelerated more hydrolysis rate of PLA film.