Shellac-based films/coatings: Progress, applications and future trends in the field of food packaging

As a natural biopolymer from the secretion of insect Laccifer Lacca, shellac shows excellent film-forming ability and safety, making it an attractive material to replace synthetic materials for food packaging. On the basis of an introduction to the structure and properties of shellac, the information on single shellac films/coatings and composite films/coatings of shellac and other bio-based materials such as proteins, polysaccharides, and lipids, including the effects of adding antimicrobial agents (i.e., natural antimicrobials, synthetic antimicrobials, and metal oxide nanoparticles) on films/coatings, was comprehensively summarized. Besides, the current application status of shellac-based films/coatings as preservation packaging for poultry products, fruits, vegetables and other food products was systematically documented. Finally, the future research directions of shellac-based films/coatings such as optimizing shellac concentrations, conducting toxicological evaluation and reducing production costs were discussed. This paper will provide guidance for a systematic understanding of the research advances on shellac-based films/coatings and possible future directions.