Efficacy of hot water immersion on lime (Citrus auranifolia, Swingle cv. Paan) fruit packed with ethanol vapor in delaying chlorophyll catabolism

- Chlorophyll catabolism in lime fruit was delayed by the combination treatment of ethanol vapor and hot water dipping.
- Ethylene production and respiration rate of fruit were inhibited in early storage period.
- The activity of chlorophyll catabolic enzymes were suppressed.

Postharvest quality deterioration in lime (C. aurantifolia Swingle cv. Paan) fruit is indicated by loss of green color as a result of chlorophyll degradation. The effect of hot water immersion on lime fruit packed with ethanol vapor pad (EP) in delaying chlorophyll degradation under storage at 10 °C was investigated. Mature green lime fruit weighing on average 250 g were immersed in hot water at 50 °C for 5 min, thereafter, packaged with 0.6 g EP or without in polypropylene trays sealed with perforated (6-mm hole) polypropylene film (25 μm thick). Postharvest quality, physiological changes and activities of chlorophyll degrading enzymes were determined. The results revealed that hot water immersion and packing fruit with EP effectively delayed chlorophyll degradation through suppressing the activity of chlorophyll degrading enzymes; chlorophyllase, chlorophyll degrading peroxidase, Mg-dechelatase, and pheophytinase in lime fruit. Furthermore, ethylene production as well as respiration was inhibited during the early stages of storage. These results suggest that hot water immersion with EP packaging inhibits chlorophyll degradation in lime fruit through suppression of chlorophyll degrading enzymes as well as ethylene production.