Study Of Edible Coatings For Physiology And Biochemistry Changes And Storage Life Of Fresh-cut Grape

The fresh-cut grape treated with edible coatings was studied their postharvest physiological properties, quality and storability during storage. At the same time, the experiment analyzed the fresh-cut grape physiology and biochemistry indexes including respiratory intensity, firmness, TSS content, TA content, weight loss rate, SOD activity, O₂^-·and MDA produce speed, relative conductance ratio, PPO activity, POD activity and phenol compounds every 15 days. In order to look for the optimum edible films and provide the theoretical fundamentals for controlling fresh-cut grape post-harvest browning and senescence. The results showed as following: 1. Fresh-cut technology was applied for the grape and realized the grape grain as basic storage and distribution pattern first time. The technology can provide the convenient, safe and high-quality fresh-cut grape for consumer, provide practical and simple storage technology for farmer and brings the considerable economic efficiency for the enterprise. 2. The fresh-cut grape treated with edible coatings has obtained the better effect. At present, fresh-cut fruits and vegetables to maintain fresh-life is commonly 7d, 10d, 15d, the longest life was 20d. In the experiment fresh-cut grape can store about 75d. Therefore this experiment is successful, and the method is feasible. 3. The results of fresh-cut grape treated with edible coatings showed that 1.0% chitosan + 1.5% citric acid + 0.5% edible-gelatin + 0.5% glycerine is the best effect; and 1.5% chitosan + 1.5% citric acid + 0.5% glycerine also have the better effect. 4. The results of fresh-cut grape senescence showed: SOD activity reduces and oxygen free radical accumulate gadually. The oxygen free radical accumulation initiated and intensified the membrane fat more peroxidation, and the membrane penetrable increased. 5. The results of fresh-cut grape browning showed: The fresh-cut grape browning was cause by enzyme catalyse response after the cell complete structure was destoried. Namely, the phenol compound in the vacuole contacting with PPO and the POD in the cytoplasm caused enzyme catalyse browning.