ALMOND GUM-CHITOSAN NANOCOMPOSITE AS EDIBLE FORMULATION FOR ADVANCING POSTHARVEST LONGEVITY OF FRUITS AND VEGETABLES

Abstract

Postharvest produces including fruits and vegetables are perishable and require preservation for prolonged shelf life. Edible coatings are emerging as a safe and value-added alternative for traditional preservation methods such as refrigeration and chemical treatments. In this article, we have developed almond gum/chitosan (AC)-based edible coating/formulation and investigated the effectiveness of coating on improving the shelf life of tomatoes and blueberries. The coated tomatoes and blueberries, after a shelf life of 25 and 20 days, respectively exhibited a significant improvement in weight loss (5%–20%), reduced acidity (1–3 folds), and kept the ascorbic acid content lower when compared to the uncoated tomatoes and blueberries. Both the coated tomatoes and blueberries did not exhibit spoilage indicating antimicrobial activity of the coating. Direct testing of the coating formulations exhibited significant anti-microbial activity against Staphyococcus aureus and Pseudomonas aeroginosa. The polymer films, prepared using the coating formulation, exhibited low moisture content (34.8 ± 2.02% and 41.5 ± 1.34%), low solubility (42.56 ± 2.3% and 31.31 ± 3.1%), low tensile strength (0.34 ± 0.05 N m−2 and 0.75 ± 0.07 N m−2) and high elongation (63.2 ± 4.12% and 71.5 ± 3.8%). These measured film properties confirm that the polymer film has good flexibility and is suitable for edible packaging. Overall, the newly developed AC edible coating exhibits significant potential for a wide range of applications within the food processing industry, offering a viable substitute for conventional wax and lipid-based coatings.