Study On Physiological Mechanism Of Chilling Injury And Pretreatment Measures Of Postharvest Eggplant

Eggplant is a typical cold-sensitive vegetables,improper storage and transportation vulnerable to chilling injury,seriously affecting its quality.In this study,long and round eggplants were used as experimental material.The effects of different storage temperature on the chilling injury of eggplants and the physiological mechanism of chilling injury were studied by measuring the index of cold injury,related physiological and biochemical indexes and texture index.The effects of different pretreatment methods on the chilling injury of long eggplants were studied.The effects of UV-C combined with oxalic acid on the occurrence of chilling injury of eggplants were studied by measuring the indexes of chilling injury,texture index,microbiological index and scanning electron microscopy.And to provide theoretical basis for understanding the mechanism of postharvest eggplant chilling injury and eggplant storage and transportation.The results showed that:(1)The chilling injury of eggplant was different at different storage temperatures.Two eggplants show symptoms of chilling injuries at 2? on the third day of storage,and at 5? on the sixth day of storage.The chilling injury index,cell membrane permeability,MDA and adhesiveness of eggplants at 2? is remarkably higher than at 5?.The springiness at 2? is significantly lower than at 5?.The weight loss rate,respiration intensity and,SOD,POD,CAT activity at 2? is significantly lower than at 5?,When the storage temperature reaches 8?,the eggplants develop no symptoms of chilling injuries until the eighteenth day and maintain TSS content,SOD,POD,CAT activity,adhesiveness,cohesiveness,springiness and chewiness comparatively well.At a same storage temperature,the chilling injuries of a long eggplant are more serious than those of a round one.(2)Different pretreatments have different effects on alleviating the chilling injury of eggplant.Cold treatment(cold water at 0? for 30 min),heat treatment(hot water at 45? for 30 s),UV-C(7 kJ/m2),oxalic acid(6 mmol/L,10 min),salicylic acid(1.5 mmol/L,10 min),chitosan(1%,1 min)treatment can reduce the degree of chilling injury,inhibit the increase in weight loss,maintain TSS content and POD activity,which UV-C treatment is best,followed by oxalic acid treatment.(3)UV-C combined with oxalic acid treatment can delay the occurrence of chilling injury of eggplant,keep the content of TSS,inhibit the increase of cell membrane permeability and MDA content,maintain POD,SOD,CAT activity,keep eggplant adhesiveness,cohesiveness,springiness and chewiness and cell integrity,inhibition of eggplant surface mold and yeast growth,reduce the total number of colonies.