Effects of 1-MCP on Postharvest Physiology of Fruits, Vegetables and Flowers
(1) Effect on ethylene production. Ethylene can cause senescence and physiological disorders in postharvest horticultural crops. 1-MCP can inhibit the normal combination of ethylene and its receptors, blocking the biosynthesis of ethylene feedback regulation.
(2) The effect on respiration. 1-MCP can inhibit the respiration of plant tissues or organs. It not only delays the peak of breathing, but also reduces the peak of breathing rate.
(3) Effects on post-ripening and softening of fruits and vegetables. There is a post-ripening process in post-harvest fruits and vegetables, accompanied by softening of fruits and vegetables. After the fruits and vegetables were treated with 1-MCP, exogenous ethylene treatment could not accelerate the softening of fruits and vegetables, which may be caused by the lack of enough new ethylene receptors in the tissues. However, if enough time and sufficient amount of ethylene-binding sites can be synthesized, exogenous ethylene can induce post-ripening of fruits and vegetables. This indicated that the inhibitory effect of 1-MCP was only related to the early ripening of fruits and vegetables, and the triggering of softening of fruits and vegetables was an irreversible process.
Effects of 1-MCP on the quality of fruits, vegetables and flowers
(1) The effect on the firmness of fruits and vegetables. Softening is one of the manifestations in the process of fruit ripening, which is very sensitive to ethylene treatment. Studies have shown that the enzymes related to softening during the ripening process are mainly exo- and endo-PG. 1-MCP can delay fruit softening, which may be related to the inhibition of softening-related enzymes.
(2) The effect on the color of fruits and vegetables. Tissue or organ color change is an important feature of senescence in postharvest horticultural crops, mainly manifested in the degradation of chlorophyll and the synthesis or appearance of other pigments. 1-MCP treatment can delay the ripening and senescence process of climacteric fruits and vegetables, and delay the change of their color.
