Development of a plant-based edible coating for extending the post-harvest shelf life and maintaining the quality of mango fruits

Abstract:

Post-harvest losses in mango constitute a critical food security and economic challenge for smallholder horticultural producers in sub-Saharan Africa, with losses of 20–40% commonly occurring between harvest and consumer markets. This study developed and evaluated three plant-based edible coatings aloe vera gel (AVG), moringa leaf extract (MLE), and cassava starch-based composite coating (CSC) for their efficacy in extending post-harvest shelf life and preserving the quality of 'Apple' mango (Mangifera indica L.) fruits stored at ambient temperature (25 ± 2 °C, 65 ± 5% RH) over a 21-day storage period. Uncoated fruits served as the control (CT). Quality parameters assessed at 3-day intervals included physiological weight loss (%), firmness (N), total soluble solids (TSS, °Brix), titratable acidity (TA, % citric acid), ascorbic acid (mg 100 g⁻¹), peel colour (L*, a*, b* values), and total microbial and fungal counts (log₁₀ CFU g⁻¹). The experiment followed a completely randomized design (CRD) with four coating treatments and three replications of five fruits per experimental unit. Results showed that the CSC treatment was most effective, reducing cumulative weight loss to 8.6% at day 21 compared to 22.4% in CT, retaining firmness (3.8 N vs. 1.2 N) and ascorbic acid (31.4 vs. 18.6 mg 100 g⁻¹), and suppressing fungal counts (2.1 vs. 4.6 log CFU g⁻¹) at study termination. The AVG and MLE coatings also significantly outperformed the uncoated control across all parameters. Sensory acceptability scores remained above the minimum acceptable threshold (5.0 on a 9-point scale) through day 18 for CSC-coated fruits versus day 9 for controls. These findings support the commercial development of affordable, plant-derived edible coatings as sustainable post-harvest management tools for tropical mango in East African smallholder supply chains.