The Effect of Methyl Jasmonate-Doped Nano-Particles and Methyl Jasmonate on the Phenolics and Quality in Monastrell Grapes during the Ripening Period

The effect produced by the application of methyl jasmonate (MeJA) in vineyards is clear, but this is a product that, despite its efficiency, is expensive, volatile and difficult to dissolve. Regarding increasing the MeJA use efficiency, new forms of application are proposed in this article, such as the use of calcium phosphate nanoparticles with two different morphologies: amorphous (ACP) and crystalline (Ap). In addition, few of the studies addressed so far have assessed MeJA’s effect during the ripening period of the grapes. As a result of this, in this article, we evaluated/studied for first time the effect of the different MeJA formats on the phenolic composition of the grape during the ripening period. The results showed small differences between the two morphologies of the nanoparticles, which promoted a significant a delay in the sugar accumulation and an increase in the different phenolic compounds compared to the control. Such improvements were not as significant as those induced by the conventional MeJA treatment. However, it is remarkable that when the nanoparticles were applied, we used a concentration 10 times lower than when it is used conventionally. Therefore, these findings revealed that both types of calcium phosphate nanoparticles are potential MeJA nanocarriers allowing for the increase in the quality of the grapes at the time of harvest in a more sustainable way, although future studies must be carried out in order to optimise the concentration with which these nanoparticles are doped.