Australian Stonefruit Grower Magazine Issue 4 April 2017 | Page 24

Research Treatment to extend storage The miraculous 1-MCP There is little doubt that the discovery of 1-methylcyclopropene (1-MCP) has been the most exciting thing to happen in postharvest technology in the last 50 years. Marketed as SmartFresh, 1-MCP has changed our understanding of fruit ripening. It has also provided a tool to extend the storage life of some fruit and vegetables by days, weeks or even months at low temperature. C limacteric fruit, such as bananas, apples and (most) and a number of storage disorders. For vegetable crops, and peaches, ripen in response to ethylene. Ethylene non-climacteric fruit, all of the effects of ethylene on quality can be added to the storage atmosphere to make fruit ripen synchronously and faster, as is done with bananas. Ethylene is also generated naturally within the fruit itself. Non-climacteric fruit include grapes, citrus, strawberries and cherries. These fruit ripen gradually while attached to the plant. Ethylene production is low to zero, remaining Enter 1-MCP. Molecules of 1-MCP bind irreversibly to the ethylene receptors within the fruit. This not only stops the fruit producing its own ethylene, but also makes it insensitive to ethylene in the air around it. Eventually the fruit (or vegetable or flower for that matter) constant throughout development. These fruit need to makes new ethylene receptors and normal processes resume. be picked when they are fully ready to eat, as few further How quickly this occurs depends on the storage temperature changes occur after harvest. and the product metabolism. For apples stored at 0°C this Ethylene does not just control ripening. It affects disease development, susceptibility to chilling injury, yellowing 24 are bad. Australian Stonefruit Grower | April 2017 takes months, whereas a fast respiring fruit or flower at 20°C can regain ethylene sensitivity in days or even hours. summerfruit.com.au