Emerging materials and technologies of multi-layer film for food packaging application: A review

Food packaging is an essential component of the development in food industry, as it is capable of protecting food from physical, chemical and biological contamination. Synthetic plastic packaging is by far the most commonly used for packaging; however, it leads to considerable environmental problems. The use of biodegradable plastics derived from natural polymers can address this issue. Nevertheless, natural polymers have poor barrier properties. This review aims to provide an overview of the various polymers used in multi-layer packaging and also to explain their physical, mechanical and barrier properties in detail. Hence, the application of a multi-layer film that combines the unique features of different polymers may produce packaging materials with improved performance, such as mechanical and barrier properties. The properties of multi-layer films with different types of polymers (biomass, synthesis-derived and microbial-derived) are thoroughly discussed. The results show that the multi-layer films possessed superior properties as compared to single-layer films in term of physical, mechanical and gas barrier properties. Suggestions for future research on the compatibility of multi-layer film in packaging applications are also addressed in this review. This paper offers an overview of the development of biodegradable natural polymer multi-layer films for packaging applications in the food industry.