Stimuli-responsive protein-based films for postharvest preservation of fruits and vegetables

The short shelf lives of fruits and vegetables, caused by a series of metabolic changes, lead to significant postharvest losses. Postharvest losses have a destructive effect on the economy, food security, and the environment. Traditional petroleum-based packaging, a static barrier incompatible with the dynamic physiological processes of fruits and vegetables, remains a hazardous environmental issue. In contrast, protein-based films for preserving fruits and vegetables are biodegradable and biocompatible. Bioactive components can be added to protein films to extend the shelf lives of fruits and vegetables by preventing microbial growth and physiological reactions, reducing food waste. However, the premature release of bioactive compounds can cause off-flavors and threaten consumer health. In this review, we discuss systems capable of releasing compounds in response to fruit and vegetable storage conditions, and the structural and compositional changes that allow for the controlled release of bioactive compounds. Proteins are investigated as carriers for synthetic and natural indicators in intelligent packaging films for real-time monitoring of fruits and vegetables. Future protein-based film research should explore developing methods of manufacturing multi-responsive films on a large scale to improve fruit and vegetable quality and reduce postharvest waste.