Effect of gamma doses on quality of unripe 'Chok Anan' mango.
Uthairathanakij A., Jitareerat P., Boonrod J.
Author Affiliation: Division of Postharvest Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, 83 Moo 8, Tientalay, Rd, Bangkhuntien, Bangkok 10150, Thailand.
: P38
Abstract : Gamma irradiation is one technique for sanitization, but there is limited data on raw fruit in particularly ripe mango, which is a popular fruit for Thai salads. Therefore the aim of this study was to investigate the effect of gamma doses on the quality changes of unripe 'Chok Anan' mango fruit. Fruit with no defects were sorted, cleaned with 200 ppm chlorinated water, dipped into Prochloraz at 500 ppm, dried and packed in carton boxes. Fruit were irradiated with gamma rays at 400 and 700 Gy and untreated fruit were used as the control. All treatments were stored at 13°C and randomly chosen to measure postharvest quality on day 1, 7 and 14. The respiration and ethylene production of fruit irradiated with gamma rays at 400 and 700 Gy reached its peak on day 1 of storage, then gradually decreased, showing that it was significantly higher than that of the control. Gamma irradiation induced peel yellowing in comparison to the control fruit. However, gamma doses did not affect the peel color change (hue angle). Mangoes irradiated at 400 Gy were firmer than other treatments after storage for 14 days. Moreover, gamma irradiation induced lipid peroxidation and lipoxygenase activity compared to that of control. Thereafter, gamma irradiation reduced lipid peroxidation throughout the storage period.