Effects Of Bagging On Color Change And Quality Of Pummelo Fruit

Citrus grandis（L.）Osbeck cv.Guanxi-miyou and Citrus grandis（L.）Osbeck cv.Sanhong-miyou originated from Pinghe county,Zhangzhou city,Fujian province,which is a famous brand of Fujian province.Fruit bagging plays an important role in improving the quality of pummelo fruits and increasing their commercial value.After the bagging,the skin of the’Sanhong-miyou’pummelo has a pale purple color when the fruit is ripe.And the color of skin in the’Sanhong-miyou’pummelo without the bag is not red.In this study,‘Guanxi-miyou’and‘Sanhong-miyou’were used as test materials and three kinds of fruit bags were selected to bag the two kinds of pummelo fruits to explore the changes of fruit color and quality during the development of different pummelo fruits,which provides theoretical and practical basis for studying the mechanism of color change of pummelo fruit and improving the quality of pummelo fruit.The main findings obtained are as follows:1 Effects of different bagging on the appearance and color of pummelo fruitsBagging can significantly improve the fruit surface brightness of’Sanhong-miyou’pummelo and’Guanxi-miyou’pummelo fruits and increase the the color parameters a^*and CCI of fruit surface.Bagging treatment is beneficial to improve the appearance and color of the fruit.Compared with the control,the color parameters L^*,a^*and CCI of the bagged’Sanhong-miyou’pummelo and‘Guanxi-miyou’pummelo fruits were higher than the control.The a*of the’Sanhong-miyou’pummelo skin treated by the three kinds of bagging treatment in the double-layer and three-layer fruit bags was significantly higher than that of the single-layer bag-treated fruits and control.The fruit surface of the’Sanhong-miyou’pummelo fruit treated with double-layer and three-layer fruit bags is obviously pale purple.Compared with the control,the chlorophyll content of the bag-treated’Sanhong-miyou’pummelo and‘Guanxi-miyou’pummelo fruits was decreased.And the chlorophyll content of the double-layer and three-layer bag-treated fruits was significantly lower than the control.The surface green reduction effect in’Sanhong-miyou’pummelo and‘Guanxi-miyou’pummelo fruits treated with double-layer and three-layer fruit bags was significantly faster than that of the single-layer bag-treated fruits and control.2 Effects of different baggings on the content of carotenoids in pummelo fruitsBagging treatment is beneficial to improve the lycopene content in the skin of’Sanhong-miyou’pummelo and promote the red color in the skin of’Sanhong-miyou’pummelo.Compared with the control,the lycopene content of the skin in bagged’Sanhong-miyou’pummelo was increased and the lycopene content of the skin in the double-layer and three-layer bag-treated fruits was significantly higher than the control.At the same times,the red color of the fruit surface of the double-layer and three-layer bag-treated fruits was more obvious than that of the single-layer bag-treated fruits and control.Theβ-carotene and zeaxanthin in the skin and juice of the’Sanhong-miyou’pummelo treated with bagging showed a tendency to rise first and then slowly decreased.There was no significant difference between the three kinds of bagging treatments when the fruit matured.Compared with the control,theβ-carotene content in the bag-treated‘Guanxi-miyou’pummelo skin was slightly reduced during fruit development.The trend ofβ-carotene content in double-layer bag-treated pummelo fruits is basically the same as three-layer bag-treated pummelo fruits.There was no significant difference between the two treatments until the fruit matured.3 Effects of different baggings on endogenous hormone content in pummelo fruitsDuring the development of fruits,the ABA content in the skin of’Sanhong-miyou’and’Guanxi-miyou’pummelo showed a downward trend while in the early stages of fruit coloring the ABA content increased in different degrees.The ABA content of’Sanhong-miyou’decreased during the later stages of development,and the decrease in ABA content was greatest in the double-layer and three-layer bag-treated.Compared with the control,the GA₃ content in the skin of the bag-treated’Sanhong-miyou’and’Guanxi-miyou’pummelo was decreased.The GA₃content in the skin of double-layer and three-layer bag-treated pummelo fruits was lower than that of the single-layer bag-treated fruits and control.Lower content of GA₃ can promote chlorophyll degradation and carotenoid synthesis,which is beneficial to the exocarp coloration of pummelo fruits.4 Effects of different baggings on the internal quality of pummelo fruitsBagging treatment had no significant effect on the single fruit weight,fruit shape index,sponge layer thickness and edible rate of the two pummelo fruits.The content of titratable acid and vitamin C in the fruit after bagging was increased.In the three kinds of bagging treatment,the fruits of the’Sanhong-miyou’and’Guanxi-miyou’pummelo treated with double-layer fruit bags have higher soluble solids,total sugar and titratable acid content.And the intrinsic quality of double-layer bag-treated pummelo fruits is better than other treatments.