Studies On Mechanism Of Decompression And Calcium Treatment Storage Of Plum Fruit

Using the Fraiar and Angeleno plum fruit as trial materials and physiological-biochemical analysis as experimental methods, the influences of varied conditions of decompression storage and calcium treatments of different consistency on the fruit quality, respiration intension and ethylene production rate, MDA content, protective enzyme activity and storage effect of plum fruits were studied. The mechanism of decompression and calcium treatments storage of plum fruit were discussed. The results are as follows:There were two obvious respiration peaks during the storage, thus indicated that the plum was a typical respiration climacteric fruit. After 30 days decompression storage, the first respiration peak appeared, which was 10 days later than those under common pressure(CK), and its peak value only accounted for 33.5% of the latter's. The second respiration peak appeared after 70 days storage, the peak value only accounted for 66.4% of those of the CK. The maximum ethylene production appeared between two respiration peaks. The maximum ethylene productions under decompression and calcium treatment appeared after 60 days storage, which were delayed 14 days and showed significantly lower peak values compared with the CK's. Therefore, decompression and calcium treatment significantly postponed the appearance of respiration and ethylene production peaks, reduced respiration rate and inhibited ethylene biosynthesis.Under two decompression ( 20.3 kPa , 50.7kPa) conditions, the hardness and brittleness of plum fruits were well preserved, the contents of SSC, TA, soluble sugar, deoxidization sugar, starch, Vc were reduced, the decrease of SOD activity and the accumulation of MDA content were slowed, the POD was kept with negative activity, thus the ripening and senescence of plum fruits effectively lingered, the storage duration was prolonged. Compared with common pressure (101.33 kPa), the plum fruit stored under 20.3kPa presented the optimum effects, and 50.7kPa takes second place.After the 1 % and 2% CaCl₂ treatments on the Fraiar and Angeleno plum fruits respectively, their contents of TA, soluble sugar , starch were maintained, the increase of SSC content was inhibited, and the hardness and brittleness of plum fruits were improved, thus preserved better fruit quality. In addition, the accumulation of MDA content was...