THE  EFFECT  OF  ETHYLENE  INHIBITOR  ON  STORED  APPLE  FRUIT  ETHYLENE  PRODUCTION  AND  OGRANIC  COMPOUNDS  CONTENT

   
   Prestorage treatments with the ethylene action inhibitor 1-methylcyclopropene (1-MCP) were tested for the efficacy at inhibiting ethylene production and ripening related phenomena on Jonagold and Sampion apples.
   Fruits harvested at optimum maturity for long-term storage, were exposed to 0.6 μl l^-1 of 1-MCP at 3℃ for 24 h and than stored in regular air at 0-1⁰C. Treated and untreated lots of fruits were analyzed after 60, 120, 180, 240 days and after additional 7 days at 20℃.
   1-MCP treatment greatly suppressed ethylene production in the fruits. However, over time, ethylene production gradually rose as the fruits slowly overcame the 1-MCP effect. It was more clearly observed in Sampion than in Jonagold apples.
   Fruits treated with 1-MCP had higher flesh firmness than control fruits after storage (up to 20 N) and also after additional 7 days at 20℃. 1-MCP did not influence apple organic acid content as expressed by titratable acidity (TA) in Sampion, but Jonagold fruits following treatment had higher TA. Fruits of both cultivars treated with 1-MCP had also higher soluble solids content.
   The results indicate that 1-MCP applied at the beginning of storage greatly affects ethylene production and maturity related processes but its efficacy depends on cultivar.
   Key words: apple, 1-methylcyclopropene (1-MCP), fruit quality, ethylene production, fruit firmness, titratable acidity, soluble solids.