Studies On Postharvest Mechanical Wound And Chilling Injury Control And Chilling Injury Sensitivity In Peach Fruit

Mechanical wound and chilling injury are two main problems of peach fruit of storage and preservation after harvest.Taking ‘Yulu’ ‘Baili’ and ‘Hujingmilu’ as objects,studying and demonstrating on controlling post-harvest mechanical injury;taking ‘Hujingmilu’ and ‘Jinxiu’ as the test materials,comparing the effect of pre-storage treatments on the control of chilling injury and experimental demonstration;the comparative analysis of the chilling sensitivity of 12 peach varieties of different types in different regions.The main results are described as:1.Taking ‘Yulu’ as the test material,controlling the harvest maturity and storage and transportation temperature,simulate transportation,and explore the effects of harvest maturity and storage and transportation temperature on logistics mechanical wound.The harvest maturity of ‘Yulu’ peach is 80%,simulating transportation at low-temperature(10℃)for 10 hours,can guarantee a shelf life of at least 5 days,the decay rate is only 15%,and the fruit is commercial.The storage life of ‘Baili’ was greatly affected by vibration.It was harvested at eight mature,simulated transportation at low-temperature(10℃),the decay rate of the control(non-vibration)fruit was less than 5% on the fourth day,while the decay rate of the 12 hours vibration group was as high as 12%.The results of experimental demonstration show that harvesting eight mature ‘Hujingmilu’ peaches,after 24 hours of cold chain logistics(with ice pack),it can be stored at 25℃ for 7 days,and the decay rate is only 6%.2.Taking ‘Hujingmilu’ as the test material,various pre-storage treatments such as temperature regulation,controlled atmosphere storage,and plant growth regulators were used to compare and analyze the effects of each treatment on the control of chilling injury.The results showed that the effects of controlled atmosphere,modified atmosphere package and the combination of modified atmosphere and ethylene absorbent/MeJA were significant,and no browning symptoms were observed during storage at 0℃ for 35 days and shelf life(20℃)for 4 days.‘Jinxiu’ was treated with LTC,airtight,and and the combination of airtight and MeJA.After 35 days of storage at 0℃ for,it was stored in room-temperature shelf(20℃)for 4 days and in low-temperature shelf(10℃)for 8 days.The combination of airtight and MeJA did not cause browning,and the quality was good.The browning symptoms of LTC during low-temperature shelf were lighter than that of room-temperature shelf.Therefore,low-temperature shelf could reduce chilling injury and prolong the postharvest storage period of fruit.The experimental demonstration results of ‘Hujingmilu’ fruit showed that the control check browned on the shelf(25℃)for 3 days after storage at 0℃ for 21 days,and the browning increased with the extension of storage time.There was no browning occurred on the shelf(21+3 days,28+3 days,35+3 days)in the airtight treatment.These results show that airtight treatment can control the occurrence of chilling injury,and the effect is significant and stable,which has the value of popularization.3.A total of 12 peach cultivars were used as test materials to carry out storage experiment to study the differences among cultivars of chilling injury sensitivity.It was found that the sensitivity of chilling injury of different cultivars was different.After storage at 0℃ for 35 days,there was no browning in ‘Jinhua’ and ‘Zhonghuashoutao’,the chilling injury was less sensitive.The browning symptom of ‘Yulu’ was the most serious,and the browning index on the fourth day of shelf was as high as 0.68,indicating that the cultivar is more sensitive to chilling injury.Among white flesh peaches,the browning index of northern peaches is generally lower than others,and the relative electronic leak and MDA content are also significantly lower than others.It can be seen that its sensitivity to chilling injury is low.The correlation analysis between the browning index,firmness,ethylene release rate and other indicators showed that juiciness was correlated with the browning index and firmness,with the highest correlation with firmness.