Abstract:

【Objective】 Effects of 1-methylcyclopropene and nitric oxide treatments on main fruit quality of ‘Whangkeumbae’ pear and related enzymes of fatty acid metabolism during low temperature storage were investigated. The action mechanisms of aroma were explored so as to provide a theoretical basis for fresh-keeping of ‘Whangkeumbae’ pear during storage. 【Method】 ‘Whangkeumbae’ pear fruits at the commercial ripe stage were fumigated with concentrations of 1-methylcyclopropene (1 μL?L-1) for 18 hours and nitric oxide gas (10 μL?L-1) for 2 hours, respectively. Changes of firmness, ethylene production, aroma compounds contents, and the activities of lipoxygenase (LOX), hydroperoxide lyase (HPL), alcohol dehydrogenase (ADH) and alcohol acyltransferase (AAT) were investigated. 【Result】 The results demonstrated that the evolution of ethylene was obviously reduced, the reduction of firmness, total alcohols and total aldehydes were obviously delayed, the increase of total esters was delayed by 1μl?L-1 1-methylcyclopropene and 10μl?L-1 nitric oxide treatments, but aroma components had some differences between 1-methylcyclopropene and nitric oxide treatments. The activities of LOX, HPL, ADH and AAT were also inhibited significantly. 【Conclusion】 The treatments of 1-methylcyclopropene (1 μL?L-1) for 18 hours and nitric oxide gas (10 μL?L-1) for 2 hours, respectively, can maintain higher storage quality of the ‘Whangkeumbae’ pear fruits, and the effect of nitric oxide (10 μL?L-1) for 2 hours is better than 1-methylcyclopropene (1 μL?L-1) for 18 hours treatment.

Key words: Pyrus pyrifolia Nakai cv. Whangkeumbae, 1-methylcyclopropene, nitric oxide, aroma components