| Abstract: |
In 2009 and 2010 years, mature green mango fruits (Mangifera indica L.) cv. Keitt were harvested in September in the two seasons and used in three separate experiments: controlled atmosphere (CA), intermittent warming (IW) and the interaction between CA & IW for eleven, eight and five weeks, respectively. Fruits of CA treatments were stored at 13ºC while those under IW and the interaction treatments were stored at 3 and 16ºC at different times. Fruits of all treatments were stored at 90-95% relative humidity (RH). Samples of each treatment were randomly taken at weekly intervals, but in the first four weeks it was taken every two weeks, to evaluate the effect of storage periods and the tested treatments.After each cold storage interval, some of fruits were taken and kept for three or six days at 20ºC and 60-70% RH (as supermarket conditions) to detect the effect of treatments on fruit quality after shelf life.All tested CA treatments maintained higher values of fruit pulp firmness (FPF), vitamin C content (VC) and Titratable acidity (TA) after both cold storage and shelf life periods. On the contrary, CA treatments decreased fresh weight losses (FWL), discarded fruits index (DFI), panel test index (PTI), peel color index (PCI), total soluble solids (TSS), activated acidity (pH) and glucose 6 phosphate dehydrogenase (G6PDH) activity after both cold storage and shelf life periods. While, CA treatments increased phosphofructokinase (PFK) activity. CA treatments showed no significant differences in chilling injury (CI) and respiration rate (RR) after both cold storage and shelf life periods.The tested intermittent warming (IW) treatments maintained higher values of FPF, VC and TA as compared with the fruits stored at 13ºC after both cold storage and shelf life periods. On the contrary, IW treatments decreased FWL, DFI, PTI, PCI, TSS, pH, RR and electrolyte leakage (EL) as compared with the fruits stored at 13ºC after both cold storage and shelf life periods. While, IW treatments increased CI as compared with the fruits stored at 13ºC after both cold storage and shelf life periods.As for the interaction treatments, it was maintained higher values of FPF, VC and TA as compared with the same treatments stored at 13ºC after both cold storage and shelf life periods. On the contrary, IW treatments decreased, TSS, pH and EL as compared with the same treatments stored at 13ºC after both cold storage and shelf life periods. While, IW treatments increased CI as compared with the same treatments stored at 13ºC after both cold storage and shelf life periods. The interaction treatments showed no significant differences in FWL, DFI, PTI and RR as compared with the same treatments stored at 13ºC after both cold storage and shelf life periods.The advance of storage period caused progressive increments in FWL, PCI, PTI, pH, PFK activity, G6PDH and EL of the weekly samples taken during cold storage and shelf life. Also, after shelf life samples the RR increased with the advance of cold storage period. On the contrary, increasing cold storage period depressed FPF, TA and VC content. The CI symptoms occurred in IW and interaction treatments only but didn’t occur in fruits stored at 13ºC.
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