Physical Changes And Quality Analysis Of 'Zhongjiao No.9'Banana During Postharvest Ripening

Banana is an important fruit in Southern China areas.However,since1996,Banana Fusarium wilt has become the main disease of banana in China.‘Zhongjiao No.9' is a new disease resistant cultivar that has been selected by Guangdong Academy of Agricultural Sciences.So far,the phenomenon of disease infection has not been found in the field experiment.Due to the lack of proper ripening and quality formation conditions of ‘Zhongjiao No.9' after harvest,studying the postharvest characteristics and fruit quality will aid in the promotion and application of this new cultivar in the future.The main results are as follow:(1)In this study,two banana culitivars namely ‘Zhongjiao No.9' and ‘Musa AAA Cavendish' were used as experimental materials.First,we studied the effects of 800mg/L ethephon treatment on the the firmness,chroma,total soluble solids,volatile aromatic compounds and shelf life of two banana cultivars that were ripened at 22°C.The results showed that ‘Musa AAA Cavendish' banana turned yellow and became softening at the same time,and produced considerable amount of aroma compounds.However,‘Zhongjiao No.9' developed poor quality under the same conditions,showing inconsistence of yellowing and softening as well as poor aroma.These findings indicate that the method commonly used for ‘Musa AAA Cavendish'ripening might not be suitable for the quality formation in ‘Zhongjiao No.9' cultivar.(2)We designed another method to ripen ‘Zhongjiao No.9' fruit.In this experiment,four treatments including: storage and ripening at 18?,storage at 18? for 1 day then transfering to 22? for ripening,storage at 18? for 2 days then transfering to 22?for ripening,and storage and ripening at 22? were used.Results showed that the use of variable temperature after-ripening storage can significantly increase the aroma level of ‘Zhongjiao No.9' and promote the ripening of peel and pulp at the same time.Specifically,‘Zhongjiao No.9' stored at 18°C for 2 days then transferred to 22?storage displayed the best quality,and this method can be used for the ripening‘Zhongjiao No.9' in banana industry.(3)We compared the fruit quality,nutrition and shelf life of ‘Zhongjiao No.9' and‘Musa AAA Cavendish' under their best ripening conditions.Results showed that the total soluble solids and shelf life in ‘Zhongjiao No.9' were superior to those of‘Musa AAA Cavendish'.However,the amino acids and sugar contents did not show significant difference between these two cultivars.Taken together,‘Zhongjiao No.9' which were preverved at 18? for 2 days then transferred to 22? for ripening manifest the best quality characteristics,providing useful information and theoretical basis for the ripening and cultivation of ‘Zhongjiao No.9' in the future.