Low oxygen pre-storage treatment is effective in reducing chilling injuries of deciduous fruit

摘要

Apple and pear fruits stored at low temperatures may suffer from chilling injury symptoms, caused by oxidative stress. Application of a low-oxygen (LO_2) atmosphere (0.5%) for 10 d at 20°C or 500 ppb 1-methylcyclopropcne (1-MCP) at 20°C for 24 h, prior to cold storage at 0°C, were equally effective in reducing superficial scald on 'Granny Smith' apples, after six months of cold storage at 0°C plus seven days at 20°C. Compared to untreated control fruit, the LO_2 and 1-MCP-treated fruit producedless ethylene, a-farncsenc and its oxidation product, 6-methyl-5-heptcn-2-one (MHO), as determined by SPME/GC-MS technique. In addition, LO_2 pretrcatment applied to Californian 'Bartlett' or Israeli 'Spadona' pears, was effective in reducing superficialscald, senescent scald and internal breakdown, after 4-4.5 months of cold storage at -1°C or 0°C, respectively, plus five to seven days at 20°C. We assume that LO_2 and 1-MCP prctrcated fruit remained free of physiological disorders, due to the reduced production of ethylene and the oxidation product MHO during cold storage.