Biopolymer-based nanocomposite films and coatings: recent advances in shelf-life improvement of fruits and vegetables

Consumers increasingly prefer healthy and nutritious diet worldwide, and demands for fresh fruits and vegetables are rapidly growing. Fresh produce are perishable commodities, and physical damage, moisture loss, biochemical changes, and postharvest microbial decay are primary causes of quality loss and reduced shelf-life. Packaging, including plastic films and coatings is an effective strategy to improve postharvest-life of whole and cut fruits and vegetables. However, plastic packaging is a significant environmental concern globally. Biopolymer based films and/or coatings are environment-friendly alternative packaging for food. But, these biopolymers, derived from plant, animal and microbial sources, lack some of the primary physico-chemical and mechanical properties compared to conventional plastic packaging. Reinforcement of biopolymer with nanomaterials addresses these shortcomings, and adds functional properties such as antimicrobial and/or antioxidant activities to the nanocomposites. Organic (e.g. nanocellulose fibrils), and inorganic (e.g. montmorillonite, zinc oxide, silver) nanomaterials are effective in achieving these improvements in biopolymer based nanocomposite. Plant-extracts and compounds derived from plant (e.g. essential oil) are also effective in imparting antimicrobial and antioxidant properties to biopolymer based nanocomposites. This is an extensive review of research works on effectiveness of biopolymer based nanocomposite films and coatings used for packaging of whole and cut fruits and vegetables to extend their shelf-life. Numerous reports have demonstrated effectiveness of biopolymer based nanocomposites in improvement in shelf-life of packaged and/or coated whole and cut fruits and vegetables by at least 4-5 days to as much as a few months.

Automated summary

Consumers' preference for healthy and nutritious diet has led to an increasing demand for fresh fruits and vegetables worldwide. However, these perishable commodities are prone to quality loss and reduced shelf-life due to physical damage, moisture loss, biochemical changes, and postharvest microbial decay. Plastic packaging is an effective strategy to extend the postharvest-life of whole and cut fruits and vegetables, but it has become a significant environmental concern. Biopolymer based films and coatings, reinforced with nanomaterials, offer an environmentally friendly alternative packaging for food, improving physico-chemical and mechanical properties and adding antimicrobial and/or antioxidant activities. This review discusses the effectiveness of biopolymer based nanocomposite films and coatings in extending the shelf-life of packaged fruits and vegetables, with reports showing an improvement of at least 4-5 days to several months.