Carnauba wax-based sustainable coatings for prolonging postharvest shelf-life of citrus fruits

Abstract

Citrus fruits are extremely popular for their rich nutritional attributes and health benefits, but they are perishable in nature, and growers and suppliers often face financial losses due to rapid postharvest decay in the fruits. In this study, carnauba wax (CW) based sustainable active coatings were developed, characterized and applied for postharvest shelf-life extension of Khasi mandarin and sweet lemon. A neem oil nanoemulsion (NONE) was used as the active agent to improve antimicrobial properties of the composite coatings. The developed coatings reduced weight loss, maintained firmness, retained total soluble solids, maintained titratable acidity, and slowed down deterioration in coated/treated Khasi mandarin and sweet lemon during storage under ambient conditions. Due to antimicrobial properties of the NONE, the composite coatings containing a 5% NONE (CW/NONE-5) and 10% NONE (CW/NONE-10) significantly reduced decay in the coated fruits compared to the uncoated control and extended the shelf-life of the citrus fruits by at least 3 weeks. The developed active composite coatings can be effective alternatives to synthetic wax coating for shelf-life extension of citrus fruits and may provide growers and suppliers with a sustainable mitigation strategy to minimize their postharvest losses.