PRASAD, K.SINGH, GURPREET2023-02-272023-02-272021M/HORT/441/2019-20https://krishikosh.egranth.ac.in/handle/1/5810194567Postharvest losses and their management in papaya fruits are always a prime concern for researchers. Hence, studies were conducted to derive an eco-friendly and health-friendly postharvest treatment for quality retention of papaya fruit. The commercial papaya cultivar of Bihar ‘Red Lady’ was assessed for postharvest losses during harvesting and storage under ambient conditions (25 ± 4º C and 65 ± 5% RH). Further, for reduction in fruit decay and retention of postharvest quality, different treatment of plant extract such as ‘Neem oil’ (2% v/v), ‘Pummelo peel extract’ (1 % v/v), ‘Pummelo essential oil’ (0.1% v/v), ‘Turmeric leaf extract’ (1% v/v), ‘Turmeric essential oil’ (0.1% v/v) along with control (water dip) were attempted as edible coating dip treatment on papaya fruit cv. ‘Red Lady’ for five minutes followed by storage at ambient conditions (25 ± 4º C and 65 ± 5% RH) for recording of observations on external and internal quality attributes during the storage period. From results, it has been observed that papaya fruit exhibited high postharvest losses which was more than 10% in terms of pathological loss and up to 15 % in terms of physiological loss. These losses could be reduced/managed significantly by the application of plant extract treatment. Among the attempted postharvest plant extract treatments ‘Turmeric leaf extract (1% v/v)’ was found to be the most effective treatment. It reduced the postharvest decay and physiological loss significantly over the control. It also improved the fruit gloss score (7.00), lowered the physiological activities of fruit in terms of respiration (6.55 CO2 kg-1 h-1) and ethylene evolution rate (60.97 μl kg-1 h-1) over control fruit (5.77, 8.34 ml CO2 kg-1 h-1 and 69.41 μl kg-1 h-1 respectively). Further this treatment positively influenced the activity of fruit browning and senescence causing enzymes such as polyphenol oxidase and lipoxygenase as it exhibited the least polyphenol oxidase (0.309 Δ A410 O.D. min-1 g-1 FW) and lipoxygenase (3.454 Δ A470 μmol g-1 FW min-1) enzyme activity compared to that of control fruit (0.350 Δ A410 O.D. min-1 g-1 FW and 4.128 Δ A470 μmol g-1 FW min-1 respectively). In terms of internal quality attributes, the treatment ‘Turmeric leaf extract (1% v/v)’ maintained the internal quality without exerting any adverse effect on TSS, titratable acidity, ascorbic acid, total carotenoids and total phenolics over control fruit. This treatment also improved the sensory score (7.2) compared to that of untreated fruits (5.8). Our results suggest that plant extract such as ‘Turmeric leaf extract (1% v/v)’ is an eco-friendly and health friendly edible coating approach which retain the external and internal quality of papaya fruit, reduce postharvest decay and extends shelf life of papaya fruit at ambient storage. Further this treatment improves the market value (sensory attribute) of fruit leading to better returns to the grower.EnglishThesis