Effect Of 1-MCP Treatment On Postharvest Physiology And Keeping Quality Of ’Zhaoxia’ Peach Fruit

Peach(Prunus persica L.)was originally planted in China,and is mainly cultured in Hebei,Henan,Shandong,Hubei,Hunan and Fujian provinces,ranking the third in production of China’s deciduous fruit trees.Since peach fruit is harvested under the conditions of high temperature and humidity,deterioration lke rapid softening and rot occurs after harvest,which has a serious impact on fruit quality and commercial value,and restricts its industrial development.1-methylcyclopropene(1-MCP)treatment can be applied as a non-poisonous and eco-friendly physical postharvest handling technology for delaying fruit senescence and maintaining quality during the storage period.’Zhaoxia’(Prunus persica L.cv.’Zhaoxia’)fruits,the major peach cultivar in Fujian province were used as the study material.The objectives of this research were to study the effect of 1-MCP treatment on postharvest quality and physiology of ’Zhaoxia’ peach fruit.The results were showed as follows:1.Effects of different concentrations of 1-MCP treatment on physiology and keeping quality of harvest ’Zhaoxia’ peach fruits.Compared with the control fruits,the treatments with 1-MCP at 0.3 μL·L-1,0.6 μL·L-1,0.9 μL·L-1,1.2 μL·L-1,1.5 μL·L-1,or 1.8 μL·L-1 lowered respiration rate and respiratory peak of peach,delayed the increase of cell membrane relative leakage rate of fruit,inhibited the decrease of hue angle(h0)value of fruit surface,keep higher fruit firmness,retarded the change of skin color of fruit,and decreased fruit weight loss and fruit decay,keep higher contents of nutritional compounds like titratable acid(TA),total soluble solids(TSS),vitamin C,soluble sugar and reducing sugar.Among the above treatment,the fruit treated with 1.2 μL·L-1 1-MCP for 12 hours could keep best fruit quality,Therefore,it could be concluded that pre-treatment with 1.2 μL·L-1 1-MCP for 12 hours could be used as the optimum conditions for maintaining fruit quality and prolonging storage life of’Zhaoxia’ peach fruits during storage at(25±1)℃.2.Effects of of 1.2 μL·L-1 1-MCP treatment on physiology and fresh-keeping of harvest ’Zhaoxia’ peach fruits.1.2 μL·L-1 1-MCP treatment effectively reduced the respiration,and delay the peak while reducing ethylene production,delayed the ethylene peak,of ’Zhaoxia’ peach fruits,and kept better membrane integrity,higher fruit firmness,and inhibited the change of fruit surface,kept higher fruit titratable acidity(TA),soluble solids(TSS),vitamin C and soluble sugar,sucrose,reducing sugar content,and decreased fruit weight loss and fruit decay,improve the effect of fruit preservation.3.Effect of 1-MCP treatment on fruit softening and cell wall metabolism of harvested;Zhaoxia’ peach fruit.1.2 μL·L-1 1-MCP treatment could maintain higher cell wall material content,delay the increase in the content of water-soluble pectin(WSP)and the decrease in contents of covalent-soluble pectin(CSP),ionic-soluble pectin(ISP),and semicellulose and cellulose,and reduce the activities of cell wall degrading enzymes such as pectinmethylesterase(PME),polygalacturonase(PG),β-galactosidase(β-Gal)and cellulase(Cx).Therefore,1.2 μL·L-1 1-MCP treatment delay fruit ripening and softening,to maintain a high commercial value.4.Effect of 1-MCP treatment on reactive oxygen species(ROS)metabolism of harvested ’Zhaoxia’ peach fruit.1.2 μL·L-1 1-MCP treatment maintained higher activities of ROS scavenging enzymes such as superoxide dismutase(SOD),catalase(CAT),and ascorbate peroxidase(APX),and higher contents of non-enzyme ROS scavenging substances like reduced ascorbic acid(AsA)and glutathione(GSH).And 1.2 μL·L-1 1-MCP treatment also effectively delayed the increase in the content of membrane lipid peroxidation product—malondialdehyde(MDA),induce a rapid increase in the production rate of superoxide anion radical(O2-·).Therefore,1.2 μL·L-1 1-MCP treatment could enhance the ROS scavenging ability,reduced generation and accumulation of ROS,and decreased membrane lipid peroxidation.