RÉSUMÉ
A significant fruit crop, the guava (Psidium guajava L.), is grown around the world in a wide range of tropical and subtropical climates. The shelf life of guavas is short, and they ripen quickly after being harvested. This limited shelf life necessitates effective management techniques to ensure a consistent market supply through post-harvest treatments to extend the storage life. In this study, we aimed to assess the impact of different treatments on the quality attributes of guava fruit cv. Lalit at 3-day intervals during storage. The experiment was carried out in the Postharvest Laboratory, Department of Horticulture, Banaras Hindu University, Varanasi. The findings from our investigation revealed that guava fruits harvested at the mature green stage and treated with Carboxy methylcellulose (CMC) and sodium alginate, maintained their desirable chemical and functional qualities for an extended period, up to 12 days of storage. Specifically, the post-harvest treatment using CMC (1.5%) proved to be exceptionally effective in reducing physiological weight loss and decay loss and retarding the increase in total carotenoids and lycopene content. Additionally, it delayed the decline in total soluble solids, ascorbic acid content, chlorophyll content, total antioxidant capacity and phenolic content throughout the storage period. Therefore, this treatment showed excellent results in extending the shelf life of guava fruits and maintaining their post-harvest quality by delaying the processes of ripening and senescence, lowering spoilage, and improving marketability and appearance.