Ethylene-induced climacteric

The use of 1-methylcyclopropene (1-MCP) to extend the shelf life of cherry tomato (.Lycopersicon esculentum var. Cerasiforme) delayed the ethylene-induced climacteric peaks in mature green and breaker fruits, chlorophyll degradation, and accumulation of lycopene and carotenoids (Opiyo and Tie-Jin 2005). Higher 1-MCP concentrations inhibited the accumulation of lycopene and carotene such that the color of the fruit did not reach that of control fruit. 

Some fruit and vegetables can be exposed to ethylene, the plant hormone produced by other commodities as climacteric fruits, during the postharvest storage and transport. This hormone can induce changes in phenolic metabolism and affect the phenolic metabolite composition and the antioxidant potential. 

Several studies on irradiation of fruits and vegetables have been conducted to delay fruit ripeness, thus, their shelf life might be extended by few days to few weeks [1]. However in some horticultural crops gamma irradiation treatments initiated the climacteric ripeness sequences by inducing the preclimacteric fruits to produce stimulatory amount of ethylene [2]. Factors most likely to affect response of fruit and vegetables to irradiation may include type of fruit (climacteric or nonclimacteric), ripeness stage at expossure, dose of irradiation and post-treatment storage conditions. 

In a large number of cases ethylene production by the fruit begins even before the climacteric. That might suggest that ethylene initiates a chain of reactions that finally leads to ripening. However, it is also conceivable that it is an early by-product of a chain of reactions induced by other factors and which then, in turn, accelerates the whole process. 

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