Effect Of 1-methylcyclopropene(1-MCP) And Controlled Atmoshere Treatments On Fruit Quality And Superficial Scald Of ‘Yali’ Pear

‘Yali’pear fruit trend to present superficial scald on peel during a long term of cold storage and at shelf life.In this study,the‘Yali’pears were treated with 1.0μL/L1-methylcyclopropene（1-MCP）,modified atmosphere packaging（MAP）and the MAP combined with 1-MCP（MAP+1-MCP）,and then they were analyzed about the quality and superficial scald incidence during cold storage and at shelf life.The results indicated that1-MCP,MAP and MAP+1-MCP treatments delayed the decrease of the fruit firmness,but had less influence on SSC.Compared with MAP treatment,there were lower concentrations of the CO₂ and C₂H₄ inside the packaging bags of MAP+1-MCP treatment,while no significant difference was showed in the O₂ content.Superficial scald of peel first appeared at 210 d of cold storage,and gradually changed more obviousat shelf life.The MAP,1-MCP and MAP+1-MCP could remarkably reduce the indexes of superficial scald,MDA content,production rate of O₂^-and relative conductivity,and decreaseα-farnesene and conjugated trienol content of peel in‘Yali’pear.Moreover,1-MCP and MAP+1-MCP treatments kept higher content of polyphenols,enhanced the activities of superoxide dismutase（SOD）and catalase（CAT）than CK and MAP treatments,and lowered the lipoxygenase（LOX）activity ofas well as inhibited the increase of polyphenoloxidase（PPO）activity at shelf life.The comprehensive analysis suggested that MAP+1-MCP treatment performed more effectively on maintaining fruit quality and inhibiting superficial scald than the single treatment.These results proposed that the superficial scald is closely associated with the accumulation of theα-farnesene and conjugated trienol,and the membrance injury induced by the lipid peroxidation and enzymatic browning caused by PPO in‘Yali’pearThis work is aimed to assess the effect of the low temperature controlled atmophere（CA）storage on reducing the incidence of fruit superficial scald and browning of core in‘Yali’pear.We set up by mixing N₂ and O₂to achieve different concentrations of O₂（1%、3%、5%、10%,respectively）,and use normal air as a control,fruit were put into each airtight container for the CA storage,in which gas mixture inflowed and outflowed at100ml/min from different sides.All fruit were kept at 0±0.5℃and RH of around of 90%throughout the storage period.During the low temperature storage and its subsequent period on-shelf,the incidence of superficial scald and browning of core as well as the changes in fruit quality and relative electrical conductivity were monitored and analyzed.Our results showed that CA treatments increase of soluble solids content was inhibited,decrease of Vc and titrable acidity contents were inhibited and keep bright of the peel at shelf life time.The treatments with 3,5,10%O₂ significantly delayed the decrease of firmness and remarkably reduced the indexes of superficial scald.The treatments with 1%O₂increased browning of core.The chilling injury incidence incresed in the case of oxygen concentration less than 3%at（0±0.5）℃storage So 5%O₂ concentation is effctive on improving the quality of‘Yali’pear。...