บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Firmness changes in ripening and ethylene-treated fruits in response to 1-methylcyclopropene

Donald Huber

Horticultural Sciences Dept., PO Box 110690, Univ. of Florida, Gainsville, FL, USA, 32611-0690

2002

บทคัดย่อ

Firmness Changes in Ripening and Ethylene-Treated Fruits in Response to 1-Methylcyclopropene

The influence of 1-methlcyclopropene on storage duration and quality has been documented for horticultural crops of diverse morphological origin. Although most horticultural commodities do respond to 1-MCP, the most dramatic effects are evident for organs displaying climacteric behavior and those exhibiting specific responses to exogenous ethylene. Among fruits, nearly all aspects of ripening are influenced by 1-MCP. In the context of postharvest handling protocols, delays in softening are of particular interest. The influence of 1-MCP on firmness changes is most certainly multi-faceted. Firmness of mature-green tomato fruit in response to 1-MCP remains unchanged for a period of days, declining eventually at rates comparable to those of control fruit and paralleling the recovery in other ripening properties. In avocado fruit, softening continues following 1-MCP treatment but at dramatically reduced rates. More generally, trends of firmness change also reflect fruit maturity at the time of treatment, and 1-MCP concentration and exposure temperature. In avocado fruit, 1-MCP delays changes in the activities of several cell wall enzymes and affects the metabolism of pectic and, to a lesser degree, hemicellulosic polymers. The recovery patterns of cell wall enzyme activities in 1-MCP-treated avocado fruit differ significantly, indicating that these proteins are differentially influenced by ethylene. Disparities in enzyme recovery may explain reports that 1-MCP treatments (i.e., deficiencies in ethylene perception) can sometimes result in abnormal texture. In watermelon fruit, 1-MCP prevents ethylene-induced placenta water soaking and phospholipid breakdown, the latter being consistent with increases in phospholipase and lipoxygenase activities in response to ethylene. A few reports suggest that 1-MCP appears promising for improving the firmness properties of fresh-cut fruits; however, the more advanced maturity of these commodities will likely require adjustments in 1-MCP treatment strategies.