Enhancing shelf-life of Mango (Mangifera indica L.) using biopolymer-based silver nanoparticle coatings

Mango fruits harvested at the right maturity ripen quickly but have a short shelf life, are prone to moisture loss, and are susceptible to microbial spoilage, resulting in severe post-harvest losses. This experiment was undertaken with the major objectives of increasing shelf life while maintaining quality. The study focuses on the green synthesis of silver nanoparticles (AgNPs) incorporated with different biopolymers (beeswax, arabic gum, chitosan, and guar gum), which formed the treatments, using the dip-coating method in two mango varieties, namely Alphonso and Bangalora. The AgNPs were green-synthesised using Sauropus androgynus (Chekkurmanis) leaf extracts and further characterised using Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) to confirm the presence of the nanomaterial. The coated fruits were stored at ambient room temperature, and their physiological and biochemical attributes were systematically monitored throughout the storage period which extended up to 16 days. The results revealed that postharvest treatments with beeswax (20% v/v) incorporated with AgNPS showed the most promising effects, extending shelf life to 16.72 days (Alphonso) and 18.86 days (Bangalora), compared to 12.8 days in uncoated fruits. This treatment also significantly reduced physiological weight loss (12%), maintained higher firmness (up to 14.43 N), and delayed increases in total soluble solids, sugars, and carotenoids. This research highlights the potential use of S. androgynus mediated AgNP-based biopolymer coatings as a sustainable postharvest method to prolong the shelf life of mangoes, making this the first report on mangoes with retention of fruit quality under ambient storage.