Valorization of agro-industrial wastes: Converting mango seed into starch nanoparticles-based edible coating for fresh produce preservation

The transformation of agro-industrial wastes into edible packaging is a promising approach within the circular economy framework. This study aimed to create a starch-based coating incorporating starch nanoparticles derived from mango seed waste and examine its impact on the quality and shelf life of tomatoes and kiwifruits when stored at room temperature at 24 ± 2 °C and 85 ± 5% relative humidity. Starch nanoparticles exhibited notable physicochemical properties. Composite films incorporating 5% (w/w) starch nanoparticles into native starch demonstrated superior characteristics such as reduced moisture content (8.89%), increased bursting strength (1281.73 g), and decreased water vapor transmission rate (5.87 × 10−3 g m−2 s−1). The results showed that the application of the edible coatings significantly improved the sensory and postharvest qualities of both fruits, including their color, weight loss, total soluble solids, pH, ascorbic acid content, firmness, and microbial counts. Tomatoes coated with the starch nanoparticle-based coating remained fresh and acceptable until the 23rd day of storage, while the uncoated tomatoes spoiled by the 16th day. Similarly, the coated kiwifruits maintained their overall acceptability until the 18th day, whereas the uncoated samples spoiled by the 12th day of storage. These results demonstrate the significance in transforming mango seed, an agro-industrial waste into valuable packaging materials via employing the utilization of starch nanoparticle-based edible coatings.