The Effect Of 1-MCP Treatment On Persimmon Fruits During Ripening And Softening

In this thesis, the effect of post harvest treatment with 1-MCP on respiration rate, the rate of ethylene production, the variation of cellwall substances (cellulose, pectin), the activities of amylase correlated with softening (CX,PG) and the fruit qualities of 'Huoshi' persimmon (Diospyros Kaki L) fruit during ripening and softening at ambient temperature (15±2)℃ were investigated. Discussions were also made on the mechanism of 1-MCP inhibiting persimmon fruit softening, which provides theoretical support for the extension of persimmon fruit post-harvested storage life.The results of study showed that the post-harvested respiratory rate variation of 'Huoshi' persimmon has the characteristics of typical climacteric fruits. There is much similarity between the changes of ethylene evolution and respiratory rate, both having a little climacteric peak to emerge prior to big that climacteric peak. 1-MCP treatment resulted in a significant decrease in ethylene evolution, and delayed appearing time of ethylene peak, ACO(ACC oxidase) activity peak and respiration peak, as well as the increase in ACO activity and respiratory rate was blocked in the early post harvest, but the height of respiration peak and ACO activity peak was promoted in the late post harvest additionally 1-MCP treatment inhibited the fall in 'Huoshi' persimmon fruit firmness and percentage of firm fruits, the hydrolysis of cellwall substances( cellulose and protopectin) and the increase of the amylase activity relating to fruit softening like PG and CX, as well as delayed the variation process in fruit TSS( total soluble solid) content .soluble tannin content, fruit peel shrink, water loss and color changes, to a certain extent lowered the fruit membrane permeability, but there is no remarkable effect on the loss of fruit Vc. It indicated that 1-MCP treatment could delay the persimmon fruit ripening and softening, so extend post-harvest the shelf life.