Gellan Gum-Based Edible Coatings Enriched with Scenedesmus spp. Extract to Enhance the Postharvest Quality and Shelf Life of Mangoes

Mango (Mangifera indica L.) is one of the most important tropical fruits; however, its limited postharvest shelf life restricts its commercial distribution. This study aimed to assess the influence of edible coatings formulated with high-acyl gellan gum (HAG), low-acyl gellan gum (LAG), and their blends enriched with an aqueous extract of Scenedesmus spp. on the preservation of mango quality during postharvest storage. The film-forming solutions based on HAG, LAG, and their combination (HAG/LAG) were enriched with Scenedesmus spp. extract at two concentrations (1 and 2% w/v) and subsequently employed for coating whole mango fruits. The coated samples were analyzed throughout storage to assess their physicochemical and physiological quality attributes, including weight loss, soluble solids content, titratable acidity, color variation, malondialdehyde accumulation, antioxidant activity, respiration rate, ethylene production, and hydrogen peroxide content. The results showed that coated fruits exhibited reduced color changes, lower weight loss, and improved visual acceptability compared to controls. Coatings containing 2% Scenedesmus spp., particularly HAG-based formulations, significantly decreased malondialdehyde (MDA) and hydrogen peroxide (H2O2) accumulation, enhanced antioxidant capacity, and stabilized respiration rate and ethylene production, delaying ripening and senescence. These effects were associated with the oxygen barrier properties of gellan gum and the antioxidant compounds present in Scenedesmus spp. Overall, the findings highlight that HAG coatings enriched with Scenedesmus spp. represent a sustainable and efficient approach to extend shelf life and preserve the physicochemical and nutritional attributes of mangoes.