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

Abstract

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.

Amorphous vs. nanocrystalline calcium phosphate as efficient nanocarriers of elicitors in vineyards

“…Nonetheless, a recent study about the effect of the different MeJ treatments on the phenolic composition of the grape during the ripening period revealed a delayed effect of Ap-MeJ treatment on the increase of the anthocyanin content in the grape skin with respect to MeJ and ACP-MeJ treatments. 25 This delayed effect was most probably associated with the need for a greater Ap-MeJ uptake, at least twice that of ACP-MeJ, due to the lower MeJ content (Fig. 2b).…”

“…Foliar applications (200 mL) were performed at veraison and one week later. This assay was carried out during 2020 season and climatological data are shown in the study by Gil-Muñoz et al 25 Vinification was carried out using a traditional methodology according to Gil-Muñoz et al 25 and analyses were measured at the end of alcoholic fermentation in triplicate.…”

“…There is an ever-increasing interest in MeJ treatment in viticulture due to its effects on the synthesis of phenolic secondary metabolites in grapes, especially flavonol, anthocyanin, tannin and stilbene derivatives. 25 These metabolites help to define sensory characteristics of wines by contributing to their color, flavor and mouthfeel properties, aging potential, stability and beneficial health effects. 26,36 Most of the studies already reported were focused on the effects of the foliar application of 10 mM MeJ during veraison on the composition of most of the families of phenolic compounds in grapes and wines.…”

“…26,36 Most of the studies already reported were focused on the effects of the foliar application of 10 mM MeJ during veraison on the composition of most of the families of phenolic compounds in grapes and wines. [24][25][26] In this work, we compared the composition of anthocyanins and tannins in wines from Monastrell grapes treated during veraison with 10 mM MeJ (positive control), Ap-MeJ (1 mM MeJ), ACP-MeJ (1 mM MeJ) and water as a control. Grapes treated with MeJ resulted in wines with a significant increase of the total anthocyanin concentration with respect to non-treated grapes (Fig.…”

“…In fact, MeJ-doped ACP NPs reduced by 10 times the required dosage of the elicitor while maintaining the quality of the harvested grapes. 24,25 However, the specific role of the NP properties in the performance (i.e., loading capacity, release kinetics, protection, etc.) and efficiency in field experiments has not been studied so far.…”