Recent advances in polylactic acid biopolymer films used in food packaging systems

The main purpose of food packaging is to maintain food quality and safety. For this purpose, packaging materials harmless to environment and health should prevent or reduce food spoilage. The packaging industry tends to natural and biodegradable materials due to migration of harmful components and causing environmental pollution of synthetic materials. The use of biodegradable materials as food packaging is one of the most studied approaches in recent years. Biodegradable polymers can be categorized in three groups as extracted from the biomass, produced by microorganisms and obtained from chemical synthesis. Polylactic acid (PLA) has unique properties as good transparency, availability in the market and low environmental impact, unlike fossil-derived materials. Compared to synthetic and other biodegradable polymers, PLA films have good tensile strength, as well as good barrier properties against flavour and smell. However, in order to solve disadvantages such as fragility and low thermal stability, plasticizers, stabilizers, fillers and antioxidants are used in the structure. In this review, it was aimed to present the latest advances in the functional properties of PLA important for its use in food packaging, namely, barrier, mechanical, thermal and optical properties, together with degradability.