Study On Cold Storage-Fresh-Keeping Technology And Chilling Injury Mechanism Of Eggplant

In this paper,the eggplant variety ’ChangFeng-2hao’ was used to study the optimal storing temperature for eggplant and the effects of cold shock treatment on chilling injury and quality of eggplant and the mechanism of improving the Cold resistance about cold shock treatment from the metabolism of active oxygen and membrane fatty acid of eggplant.The results are as follows:1. The selection of the best reserve temperature of eggplantThe author researched the influence of different temperature which are (6±0.5) ℃, (8±0.5) ℃, (10±0.5) ℃, (12±0.5) ℃ etc. on eggplant respiratory intensity, hardness, soluble protein.The results indicated that:the hypothermia of 6 and 8℃ could significantly inhibit the respiratory intensity of eggplant,keep the fruit hardness,reduced the consumption of nutrients such as soluble protein and total sugar.However, storing under hypothermia too long However, storing under hypothermia too long caused the chilling injury of eggplant. Though the chilling injury was not occurred when it stored above 10 ℃, its respiratory intensity was strong, nutrients consumed so quickly and fruits corrupted and aged easily. So we considered that the optimal storage temperature and the critical temperature of chilling injury was 10 ℃.2. The influence of cold shock treatment on storage quality and chilling injury of eggplantEggplant were treated with-1 ℃ refrigeratory for 1 h,2 h,3 h,4 h and 4℃ refrigeratory for 4 h,6 h,8 h,10 h respectively, then stored at the temperature of 6℃ with the control group for 15 d. The results showed that the effects of eggplant would be the best when treated with 4℃ refrigeratory for 8 h,which reduced the chilling injury index and incidence of eggplant significantly and maintained the nutritional value and appearance quality well.3. The effect of cold shock treatment on the active oxygen metabolism of eggplantThe eggplant which treated with 4 ℃ refrigeratory for 8 h and the control group was used to study the metabolism of active oxygen of eggplant during storage.The results showed that cold shock treatment obviously controlled the accumulation of O2- and H2O2 content of eggplant during storage,significantly improved the activity of SOD, CAT and APX which can eliminate active oxygen, inhibited the decrease of Non enzymatic antioxidants about GSH and AsA,and alleviated chilling injury degree. By PA and PCA, we found that the key index which cause chilling injury was the content of H2O2,the main factors that impact cell membrane permeability were O2- and H2O2.Effect of cold shock treatment is reflected in the significantly increased of activity of CAT and SOD and the content of AsA then reduced the chilling injury occurrence of eggplant.4.The effect of cold shock treatment on membrane fatty acid metabolism of eggplantThe eggplant which treated with 4 ℃ refrigeratory for 8 h and the control group was used to study the changes in membrane fatty acid composition and content of eggplant during storage. We found that that in eggplant fruits, the main unsaturated acid were oleic acid, y-linolenic acid and linoleic acid,whereas the main saturated fatty acid included stearic acid and palmitinic acid. Cold shock treatment inhibited the increase of stearic acid and palmitic acid of eggplant during storage,reduced the oxidation of unsaturated fatty acid about linoleic acid and linolenic acid, increased the relative content of oleic acid, enhance the value of the U/S. It indicated that the increase of the unsaturation of membrane fatty acid and U/S value is closely related to the improving of the cold resistance in cold shock treatment.