Study On Fresh Keeping Treatment Of Red Globe Grape By Of Chitosan

Red globe grape which belongs to grape vpp. It's a main variety of spreading and cultivate in our country. In order to relay the supplying and decrease the loss of nutrition during storage, It was reported about storage and refreshment for grape Before, which limited to use chemical Fresh keeping agent and SO₂ treatment, the result showed that remains on the surface of fruit. Although using chitosan for refreshment of grape .The study limited on the intensity of breath, appearance of quality and intension material of fruit. So the author used red globe grape as experiment material and chitosan as Fresh keeping agent, from July in 2004 to September in 2005,researched on the effect of appearance of quality, intension material of fruit and physiological activity. Then discuss the best concentration of chitosan, treatment compose and storage environment in order to red globe grape.The main conclusion is as follow:1 . The best concentration is 1.0% of chitosan.hardness of fruit, soluble solid and titrataboe acid begin to decrease, the range of decrease is lower than compare treatment, among of all the change of treatment with 1.0% of chitosan is the slowest. The second is 0.9%,1.1%,1.3% of chitosan.The loss of reducing sugar is low,Vc increased from 0 to 45^th day and then decreased. Vc of the treatment with 1.0% of chitosan is 9.43mg/100g until 103th day .Which is 2 times of 0.9% of chitosan and 3 times of 1.3% of chitosan.soluble protein reah the highest in 15th day and then begin to decrease. The decrease is slowest by treatment of 1.0% of chitosan.2. Chitosan treatment is the best in 3 kind of treatment method, which including chitosan, , SO₂.During storage of red globe grape, The hardness of fruit decreased soluble solid , titrataboesolid, reducing sugar, soluble protein increased from 0 to 15^th day and then decreased .Expect for soluble solid and protein by treatment of Sodium diacetate ,The other two treatment is slower the compare treatment and the treatment with chitosan is the slowest. The second is SO₂ treatment,However storage time of 1.0% chitosan treatment is more 43d than 0.25% of Sodium diacetate's,and is more 23d than SO₂,CK,1.0% of chitosan is the best in three fresh keeping agents. The second is SO₂ treatment, The worst is 0.25% of Sodium diacetate.3. It is the best refreshment compose for red globe grape that 1 % of chit san immerse I min andstorage temperature 0.5 °C,The research focus on the effect of the quality of the red globe grape ,physiological activity .Storage temperature concentrate of chitosan and immerse time with chitosan treatment .The result show that the storage temperature is the main factor to effect refreshment of grape .In the period of refreshment with chitosan ,with the increase of rate of leave, corrupt and weight loss ,The soluble solid ,hardness of fruit decline and activity of SOD decrease. Concentrate of MD A increase ,intensity of breath and activity of Pectin enzyme is from increase to decrease, activity of POD enzyme increase .The above result reflect that the treated red globe grape decrease the capability of clearing active oxygen , increased the extra-oxidize activity of film-fat and the fruit become gradually old .