| Actinidia chinensislanch belongs to Actinidiaceae Actinidiaindl.Plant,the fruit is rich in important nutrients and functional ingredients such as vitamin C,phenols,acids,carbohydrates and amino acids,which has high nutritional and medical value.kiwifruit is a typical respiratory climacteric fruit,It takes a period of time to reach the edible state after harvest,After reaching the edible state,it will quickly rot,So it can't be eaten immediately and can't be stored after being softened,Seriously reducing the consumer's enthusiasm for purchasing and affecting the development of the kiwifruit industry.As one of the main varieties of kiwifruit in China,‘Xuxiang' kiwifruit has been favored by consumers in recent years because its flavor is more suitable for the taste of orientals.In this paper,'Xuxiang' kiwifruit was used as experimental material to study the effect of harvest time on shelf-life quality and determine the appropriate harvest time;Kiwifruit with different post-ripening was treated with 1-MCP to explore the appropriate treatment conditions for prolonging the shelf-life of 'Xuxiang'kiwifruit;Ethylene slow-release agent was used to ripen 'Xuxiang' kiwifruit and response surface analysis was used to study the effect of different conditions on shelf-life quality,In order to provide theoretical basis for prolonging the shelf life of'Xuxiang' kiwifruit.The main results and conclusions are as follows:(1)The suitable harvest time of 'Xuxiang' kiwifruit was when the dry matter content reached 17.67%,after the fruits reached the edible state,they can be stored for about 12 days at 20? and 60 days at 2?.The indexes were the content of soluble solids at 20? was 15.77%,the firmness was 0.95kg·cm-2,reducing sugar content was 3.45%,vitamin C content was 51.12mg·100g-1;Soluble solids content at 2? was 16.34%,firmness was 1.51kg·cm-2,reducing sugar content was 6.17%,vitamin C content was 47.41mg·100g-1.After 2? storage,the content of soluble protein was high,reaching 4.60mg·g-1,the special aroma components were 2,2-dimethyl-3-octene,1,2,2-trimethylbutyl-cyclohexanol.The sensory evaluation quality was the best.(2)After post-ripening I(soluble solid content was 12.04%)and post-ripening II(soluble solid content was 13.9%),0.50?L·L-1?0.75?L·L-1?1.0?L·L-1 1-MCP had a weak effect on respiratory intensity,titratable acid content and firmness,but had a greater effect on reducing sugar content and vitamin C content.The three concentrations of 1-MCP can delay the degradation of vitamin C in Kiwifruit during ripening,and can slowly increase the content of reducing sugar;The use of 1-MCP can also cause the reduction of aroma types of kiwifruit,When the solid content was 12.04%,the kiwifruit treated with 0.75?L·L-1 1-MCP did not reduce the aroma.The sensory quality of the fruit was greatly influenced by three concentrations of 1-MCP in post-ripening I and II,and the sensory quality of the fruit was the best in post-ripening I 0.75?L·L-1.The edible period of the fruits treated with 1-MCP at 2? was about 60 days,but the firmness,vitamin C,soluble protein content,aroma species and sensory scores treated with post-ripening ? were not as good as post-ripening I.It shows that the post-ripening II is not suitable as a time node for the 'Xuxiang'kiwifruit.In general,the quality of post-ripening I 0.75?L·L-1 1-MCP treatment group was the best,and the result of treatment actually reached edible state after 30 days storage at 2?.to storage after 60 days,the main quality indexes were:soluble solid content was 16.95%,firmness was 0.95kg·cm-2,reducing sugar content was 6.75%,vitamin C content was 57.46mg·100g-1;soluble protein content was 3.6mg·100g-1.20 kinds of aroma components were detected.The specific aroma components were 3-(1,3-dihydroxyisopropyl)-1,5,8,11,14,17-hexyl-ChloroNonane,Trifluoromethyl tert butyl disulfide,linalool,4-hexene-l-ol,6-methylbicyclo[4.2.0]octane-7-ol,sensory evaluation was the best.(3)According to the central composite design theory of response surface,the ripening experiment of‘Xuxiang' kiwifruit was carried out,the quadratic multiple models of various indexes and experimental factors were established.After verification,the regression model is significant,which can better reflect the relevant changes in the ripening process of 'Xuxiang' kiwifruit.Using design expert 11 software to optimize the analysis,the optimal process parameters were determined as 4g of ethylene slow-release agent,treatment temperature 25?,treatment time 24h,storage temperature 11?.After storage for 8 days under this condition,the firmness of kiwifruit was 0.762kg·cm-2,the soluble solid content was 11.778%,the vitamin C content was 32.442mg·100g-1,the soluble protein content and sensory scores were better. |
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