Methyl jasmonate treatments influence bioactive compounds and red peel color development of Braeburn apple

The present study was carried out to determine the effects of methyl jasmonate (MeJA) treatments on the fruit peel color parameters, anthocyanin content, ethylene biosynthesis, phenolic content, and antioxidant capacity of Braeburn apples. Experimental trees were treated with 1120, 2240, or 4480 mg L-1 MeJA at 1- and 2-week intervals between the 105th and 175th days of growth after full bloom. L* and hue decreased linearly with increasing MeJA concentrations in both experimental years. While MeJA treatments did not cause significant changes in chroma, except for in the final harvest in 2010, it decreased chroma values significantly on all sampling dates of 2011. Anthocyanin content, internal ethylene concentration, phenolic content, and antioxidant capacity increased linearly with increasing MeJA concentrations, regardless of the application interval: MeJA treatments with 1-week intervals were found to be as effective as those with 2-week intervals. Although MeJA treatments increased ethylene biosynthesis, they did not cause any softening; on the other hand, fruit firmness increased linearly with increasing MeJA concentrations. Preharvest MeJA treatments can be a good management strategy for red peel color development and fruit firmness preservation in Braeburn apples. Although both application regimes of MeJA significantly increased red color development, the treatments with 1-week intervals were found to be more effective than 2-week intervals with regard to phenolic content and antioxidant capacity.