Effects of Different Types of Fruit Bags on Color Formation and Pigment Accumulation of ‘Fuyu’ Persimmon Fruits

To study the effect of fruit bagging with different types of bags on color formation and pigment accumulation of ‘Fuyu’ persimmon fruits, 4 types of glass bags and 3 types of popular paper bags were selected to bag ‘Fuyu’ persimmon fruits on June 25, and the fruits were picked off by batches on Aug. 25, Sept. 10, Sept. 20, Oct. 2, Oct. 12, Oct. 25, Nov. 2, Nov. 12 respectively. Nonbagged fruits were used as control in the tests. The results showed that the chlorophyll content in the pericarp dropped significantly when covered by less transparent bags at the early stage of fruit development, which accelerated the chlorosis process of the young fruits. The period of time from Oct. 2 to Nov. 2 was critical to ‘Fuyu’ persimmon fruit coloration, during which the fruit color turned to orange, red orange from green, which was also the key stage of the influence of bagging on carotenoid content increment. It was showed that color L, color a and each pigment component were not significantly correlated, and the correlations among the color a and the total pigment and each pigment component were higher than those of the color b. The persimmon fruit color development was caused by accumulation of 5 kinds of carotenoids, among which cryptoxanthin and β-carotene played a critical role. The results showed that the bagging with yellow glass paper bags was conductive to color formation and pigment synthesis, whereas red light and weak light were not conducive to pigment synthesis, which had more negative impact on ‘red’ pigment accumulation.