Regulation of fruit ripening by 1-methylcyclopropene and apple storage

Since autumn 2005 treatment of apples with SmartFresh™ (active compound 1-Methylcyclopropene, MCP) is permitted in Switzerland. MCP is an ethylene inhibitor. It binds to the ethylene receptors and prevents ripening processes which are induced by ethylene. Enthusiastic postharvest scientist called it the “magic pullet” and presumed that application of this compound will revolutionize storage technology as did at its time of introduction the CA-storage technology. In most apple cultivars firmness and acidity are well maintained during storage and in particular after storage during distribution and retailing. Thus freshness of apples is well retained up the time of consumption. There are some cultivars such as Breaburn which should not be treated with MCP because it promotes development of disorders such as brown core or brown heart (BBD). It is advisable to reserve MCP treatment only for top quality apples in an optimal ripeness stage. Treatment of apples of too progressed ripeness shows no effect. Future research should focus on establishing cultivar specific optimal ripeness stages for MCP treatment to ensure desired effects and maximal benefits.