Biodegradable biopolymers for active packaging: demand, development and directions

The food packaging industry is a major contributor to plastic waste. The end-of-life scenario of fossil-fuel derived plastics often has a detrimental effect on the natural environment, including the formation of microplastic pollution and increased GHG emissions. Therefore, alternative food packaging materials are required to overcome these effects and reduce the unsustainable use of plastics. The sustainability of biopolymers is related to the valorisation of waste, the abundance of the source, and the biodegradability of the material. Conventional fossil-fuel based plastics often have the ideal properties to protect food from environmental conditions which enhance food degradation. Therefore, bioplastics require equal or superior mechanical and barrier properties to outcompete traditional plastics. Here we review the use of biodegradable biopolymers for active food packaging, discussing bioplastics at the forefront of active packaging research. Particular attention is paid to the source of the biopolymer, the film properties, and different scale-up technologies used to produce active packaging materials. The variation in bioplastic properties upon incorporation of active agents is also explored. Moreover, the controversies relating to biodegradable certifications are discussed. This review builds upon current literature by providing a specific overview of biopolymers in the context of their use as active packaging materials. Overall, it is evident that active packaging prospects will rely on; (i) bio-based and biodegradable bioplastics (ii) optimising the properties of bioplastics containing active agents, (iii) adhering to strict safety regulations of food contact.