Abstract: Volatile C6 and C9 alcohols and aldehydes are the characteristic aroma compounds of muskmelon, which are derived from the lipoxygenase (LOX) pathway of unsaturated fatty acids. The effect of postharvest Trichothecium roseum inoculation and benzothiadizaole (BTH) treatment on the enzyme activities involved in the LOX pathway and the release of characteristic aroma compounds from muskmelon (Cucumis melo L. cv. Yujinxiang) was investigated and the correlation between the independent variables was evaluated. The results showed that T. roseum inoculation increased the enzyme activities involved in the LOX pathway compared with control and BHT-treated fruit and the peak occurred earlier in inoculated fruit than in uninoculated one. The peak values of LOX and alcohol dehydrogenase (ADH) activity in the peel and pulp of BTH-treated fruit were higher than those of the control group by 3.49%, 3.93% and 5.13%, 7.21%, respectively; alcohol acyltransferase (AAT) activity was inhibited by BTH in peel and pulp tissues by 19.03% and 14.79%, respectively. The release of C6 and C9 aroma compounds was motivated by T. roseum inoculation, which had a positive correlation with the changes in the LOX pathway enzyme activities. The emission of C6 and C9 aroma compounds from BTH-treated fruit was lower than that from control fruit, which had no significant correlation with the changes in the LOX pathway enzyme activities. BTH treatment could improve disease resistance, and inhibit aroma emission from postharvest muskmelon.

Key words: Trichothecium roseum, benzothiadiazole (BTH), lipoxygenase pathway, characteristic aroma