Studies On Storage Characteristic And Mechanism Of Mango By Postharvest Heat Treatment

"ivory Mans" is used as raw material in this study, the effect of heat treatment on mango storage quality were elucidated and the optimal heat treatment conditions were established; the internal contact between physiological and biochemical changes and mango quality changes after heat treatment was analyzed, and it provided theoretical basis for the research of mango heat preservation mechanism. Furthermore, the mango storage test was also conducted and it could provide a new commercialization technology for mango storage. The conclusions were followed:Through the analysis of mango surface characters, determined the highest heat-resisting temperature is70℃. Mango exposed to50℃,55℃,60℃,65℃and70℃hot water and the quality changes was assessed by principal component analysis. The results found that the appropriate heat treatment conditions were50℃-10min,60℃-1min and70℃-5s.The effect of heat treatment on storage quality and physiological and biochemical changes were investigated after mango treatment with50℃-10min,60℃-1min and70℃-5s. The results showed that: (1) Heat treatment could significantly inhibit the decrease of sound fruit rate, titratable acid and Vc content, reduce the increase in the fruit weight loss rate, but no significant effects on the TSS content and fruit turn yellow rate.(2) The mango belongs to climacteric fruit. Heat treatment significantly inhibited the rise of respiration intensity during mango storage while suppressed physiological activities, but did not alter the arrival of the respiratory peak. Respiration intensity changes during storage and the changes of sound fruit rate had a high degree correlation (r=-0.987).(3) Heat treatment significantly reduced both the cell membrane permeability and the MDA content, enhanced the increase of total phenols, flavonoids content, CAT and SOD isozyme activity. Results displayed heat treatment could maintain the integrity of the cell membrane as well as higher antioxidant activity, improve mango self-defense capability. There was a significant correlation between the changes in cell membrane permeability and MDA content and sound fruit rate (r1=-0.691, r2=-0.917).(4) Heat treatment restrained the activity of amylase and PG in vivo during mango storage, at the same time the fruit hardness was maintained. The hardness changes in the early storage and amylase and PG activity showed a significant negative correlation (r1=-0.780, r2=-0.974).(5) Heat treatment induces the synthesis of HSPs in mango, SDS-PEGA proved that the molecular weight of HSPs concentrated at49KD and the interval between60KD and85KD. HSPs increase the defense capability of mango, curing the respiration and enzymatic reaction, delaying fruit senescence.In order to optimize the storage technology of mango, the orthogonal test was carried out with heat treatment, storage temperature and other preservation treatment as factors. The results showed that60℃-1min treatment combined with0.15%chitosan soaked and low temperature storage at10℃was able to maintain the best quality of mangoes during storage, The rate of sound fruit reached up to72.67%after storage for40days.