Effect of methyl jasmonate on phytonutrient and physical properties of harvested 'Nam Dok Mai' mango

The effect of methyl jasmonate (MeJA) on the phytonutrients (β-carotene, total carotenoids) and physical properties (color changes) of mango fruit ‘Nam Dok Mai’ was investigated. The mango fruits were harvested at the mature-green stage and disinfected the fruit surface with 100 ppm sodium hypochlorite solution. The fruit samples were then fumigated with 30 ppm MeJA in an enclosed container at 25°C for 6 h, then stored at 13°C for 18 days. Non-treated fruits were used as control. The β-carotene content of mango flesh was analysed using high performance liquid chromatography (HPLC), and the spectrophotometer was used for measuring total carotenoid contents in peel and flesh. The results revealed that MeJA treatment enhanced the accumulation of β-carotene content throughout the storage compared with non-treated fruit. The increase of β-carotene content was not correlated with color changes (b* values and Hue angle). Also, total carotenoid contents in both peel and flesh of MeJA treated fruit increased, particularly in peel, there was 5-8 folds greatly higher than in flesh. However, MeJA treatment did not affect the changes of peel colors (b* values and Hue angle) when compared with the control. This result indicates that MeJA treatment may accelerate the accumulation of β-carotene and total carotenoid contents of mango fruit during storage at low temperature.