Studies On Mechanism Of Low Temperature And Calcium Treatment In Storage Of Plum Fruit

Plum is one of the widely planted temperate-zone tree fruit in the world.Consumers like plum fruit extraordinary because of its special flavor.The storage and transport time of plum fruit in ambient temperature is limited because of its high perishable nature(softness and decay).Low temperature and calcium treatments can prolong the storage time.But there are huge variation in plum cultivars,their storage characteristics,particularly their tissue structure,physiological and biochemical characters,as well as harvest date.With plum fruits 'Fraiar' and 'Angeleno'(Prunus salicina Lindl.) as trial materials and physiological-biochemical analysis as experimental methods,we carried out the analysis of the influences of low temperature(5℃,2℃,0℃,-0.7℃and ambient) and calcium hypochlorite treatments(1500 mg/L,1000 mg/L,500 mg/L and CK) on the fruit quality respiration rate,MDA content,protective enzyme activity and storage effect of plum fruits.The mechanism of low temperature and calcium hypochlorite treatments in plum fruit storage were discussed.The results are as follows:1.Under different low temperature treatments,the plum fruit firmness were well preserved, while the rapid decreasing of SSC,the contents of titratable acids,total sugar and Vc the decrease of superoxide dismutase(SOD) activity and the accumulation of malondialdehyde(MDA) content were slowed down during the storage,peroxidase(POD)was kept with negative activity,thus the ripening and senescence of plum fruits were effectively retarded.The storage duration was prolonged in return.In general,the most optimal environmental temperature for 'Fraiar' and 'Angeleno' plum fruit storage varies from 0℃to 2℃.2.After calcium hypochlorite treatments at 1500mg/L on 'Fraiar' and 'Angeleno' plum fruits respectively,their contents of Titratable acidity(TA) and total sugar,the increase of SSC content was inhibited,and the fruit firmness were improved,thus preserved better fruit quality.In addition, MDA accumulation was inhibited.POD activity and the rotting rate were depressed,while SOD activity was enhanced,thus increased the antioxidant ability in the fruits.The ripening and senescence of plum fruit effectively lingered with the prolonged storage.