Biodegradable Synthetic Poly(Lactic Acid) (PLA) for Food Packaging Application

Poly(lactic acid) (PLA) is a microbial polysaccharide that has gained popularity as a biodegradable polymer and an effective alternative to synthetic plastics. In the context of increasing consumers' concerns about the harmful impacts of synthetic plastic packaging on their health and the environment, researchers have been developing biopolymer-based packaging material that can replace this synthetic plastic packaging. This chapter is a synoptic discussion on the synthesis and types of PLA and PLA-derived biodegradable polymers, their properties, improvements in mechanical, physicochemical, and barrier properties, and food packaging applications. Moreover, composites of PLA with synthetic plastic polymers such as polyethylene, polypropylene, polyvinyl alcohol, and polyethylene terephthalate, and with other biopolymers such as chitosan, cellulose, and starch, have also been explored and evaluated. Additionally, stereocomplex (SC) PLA, blends of poly(L-lactic acid) and poly(D-lactic acid), and their improved mechanical and barrier properties have been elaborated. The incorporation of fillers such as graphene oxide, montmorillonite, cellulose nanocrystals, and other active agents has been shown to improve the functional properties of biopolymer-based composite packaging materials. Finally, the chapter summarizes applications of PLA-based composite materials in the packaging of perishable foods like fruits, meat, vegetables, and processed foods like cheese, cake, and others.