Study On The Fresh-keeping And Aroma Changing Of Hybrid Orange In Storage

The Hybrid orange is the offspring which the Citrus reticulata(or crossbreed) hybridize Orange and grapefruit. The main characteristics is beautiful fruit, excellent quality, perdurable store, early fructification and fertility stabilization.lt is considered that is the chief breed in the 21th century. Because Hybrid orange is new crossbreed, there are few publications about Hybrid orange. In order to improve the quality of fruit, this thesis focused on the research of keeping fresh and the changes of aroma of Hybrid orange.The chitosan coating package and ozone methods were investigated to keep hybrid orange fresh in the normal temperature using Amacan, Nankou and Novo as materials, the changes of the main aroma components during storage of Nankou were also explored. The result showed:(1)The decrease of the activities of superoxide dismutase and the increase of electric conductivity could be restrained by the treatment of moderate concentration of ozone. In the chitosan coating package, the physiological process of Hybrid orange was becoming slower envidencely except the third group,fourth group and eighth group.(2)The quality of Hybrid orange in storing is superior to the controlled in storing. The quality changing rule of Hybrid orange in storing is that the contents of moisture, the total acid, reducing-sugar and Vitamin C constantly reduces as the storing time increases.(3)Considering the physiological process after picking, storing-quality and putrescence,it can be confirmed that the optimal conditions for Amacan, Nankou and Novo fresh-keeping were 13 mg/L ozone twice a day,90% RH; 13 mg/L ozone three times a day, 85% RH; and 16 mg/L ozone two times,80% RH respectively. This indicates that the ripening and senescence of fresh hybrid orange can be delayed by ozone treatment; Amacan could be stored better than Nankou and Novo in the same condition.(4) In the chitosan coating package, the third group,fourth group and eighth group were rotten in storing for 30 days, so we analyzed the rest six groups. Considering the physiological process after picking, storing-quality and putrescence,it can be concluded that the optimal conditions for Amacan, Nankou and Novo fresh-keeping were chitosan 2.0%, dehydrogenation sodium acetate 0.1 g/Kg and 4.0% calcium chloride; chitosan 2.0%, dehydrogenation sodium acetate 0.3 g/Kg and 2.0% calcium chloride; and chitosan 2.0%, dehydrogenation sodium acetate 0.1 g/Kg and 4.0% calcium chloride; Amacan could be stored better than Nankou and Novo in the same condition. (5)The changes of the main aroma components in the two conditions of chitosan coating package and ozone were analyzed respectively.It was found that the content of the main aroma components is downtrend and the quality of fruitage was worse and worse during storage of Nankou.