Postharvest respiration rate, physiological weight loss and physico-chemical quality of mango fruit as influenced by different hot water quarantine treatments under simulated shipment conditions

Abstract

Extended hot water quarantine treatment (HWQT) is a commercial phytosanitary measure used for fruit fly disinfestation in mangoes. These studies were targeted to evaluate the physiological behaviour and qualitative response of hot water treated fruits of late maturing mango cv. Sufaid Chaunsa under two different commercial shipment conditions including ambient shipment (28 ± 2 °C; 60-65% RH; simulated for air freight) and refrigerated shipment (10 ± 1 °C; 80-85% RH; simulated for containerized shipments through sea-freight or land routes). The fruits were harvested at physiological maturity, de-sapped (0.5% lime; 2-3 min dip), precooled to 20 °C (forced-air cooling), transported (350 km) in a reefer van (at 20 ± 1 °C), and subjected to two HWQT protocols i.e. 48 °C for 60 min and 45 °C for 75 min in comparison with control. HWQTs were found to have significant impact on physiological aspects of the fruits with significantly more weight loss and higher rate of respiration as compared to control. The fruits subjected to 48 °C for 60 min had more weight loss and higher respiration rate as compared to those at 45 °C for 75 min. Water temperature was found more critical than the treatment duration in causing fruit weight loss. HWQT protocols did not have negative impact on physico-chemical fruit quality attributes under both shipment conditions. Based upon respiratory peak, 3 weeks storage at 10 ± 1 °C; 80-85% RH was found better along with 7 days post-shipment shelf life as it maintained better eating quality at retail. The turnout is expected to be much better at neighbouring export destinations (situated at less transition/transport periods); however, the inclusion of disease control strategies at pre and postharvest levels is indispensable for low temperature shipments.