Nanoparticles doped with methyl jasmonate: foliar application to Monastrell vines under two watering regimes. An alternative to improve grape volatile composition?

BACKGROUND: Elicitors induce defense mechanisms, triggering the synthesis of secondary metabolites. Irrigation has implications for a more sustainable viticulture and for grape composition. The aim was to investigate the influence on grape aroma composition during 2019 and 2020 of the foliar application of amorphous calcium phosphate (ACP) nanoparticles and ACP doped with methyl jasmonate (ACP-MeJ), as an elicitor, with rainfed or regulated deficit irrigation (RDI) grapevines. RESULTS: In both growing seasons, nearly all terpenoids, C13 norisoprenoids, benzenoid compounds and alcohols increased with ACP-MeJ under the RDI regimen. In 2019, under the rainfed regime, ACP treatment increased limonene, p-cymene, α-terpineol, 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), 2-ethyl-1-hexanol, (E,E)-2,4-heptadienal, and MeJ concentration in comparison with control grapes. In 2020, the rainfed regime treated with ACP-MeJ only increased the nonanoic acid content. Grape volatile compounds were most influenced by season and watering status whereas the foliar application mainly affected the terpenoids. CONCLUSION: A RDI regime combined with the elicitor ACP-MeJ application could improve the synthesis of certain important volatile compounds, such as p-cymene, linalool, α-terpineol, geranyl acetone, ß-ionone, 2-phenylethanol, benzyl alcohol, and nonanoic acid in Monastrell grapes. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Could foliar applications of methyl jasmonate and methyl jasmonate + urea improve must grape aroma composition?

BACKGROUND: Grape aromas are formed by a great number of volatile compounds. Methyl jasmonate (MeJ) and urea (Ur) foliar applications have been studied to improve grape quality, but their combined application has never been studied. RESULTS: In both seasons, MeJ application enhanced terpenoids and C6 compounds synthesis, though decreased alcohols content. Moreover, MeJ + Ur treatment reduced benzenoids and alcohols and did not affect C13 -norisoprenoids content. However, there was no clear effect of these treatments on the rest of the volatile compounds. Multifactorial analysis showed a season effect on all volatile compounds, except terpenoids. Discriminant analysis showed a good separation among samples under treatment criterion. The great effect of MeJ treatment on terpenoids was probably due to this elicitor influencing their biosynthesis. CONCLUSION: Season has a strong influence on grapes aromatic composition since it affects all volatile compound families except terpenoids. MeJ foliar application enhanced terpenoids, C13 -norisoprenoids and C6 compounds synthesis, whereas decreased alcohols content; however, MeJ + Ur foliar treatment did not affect C13 -norisoprenoids and C6 compounds, and decreased benzenoids and alcohols grape compounds. Therefore, no synergistic effect was observed between Ur and MeJ on grape volatile compounds biosynthesis. Foliar application of MeJ seems to be sufficient to improve the aromatic quality of grapes. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Optimization of thin film-microextraction (TF-SPME) method in order to determine musts volatile compounds.

It is well known that grape aromatic composition is directly correlated to the final wine quality. To determine this composition, a previous stage of selective extraction is necessary, since the aromatic compounds are found in very low concentrations in the grapes. Therefore, in this work, the thin film microextraction technique (TF-SPME) was optimized, for first time, with the aim to analyze the volatile composition of the grape musts. The results obtained with the two commercially available absorbent materials for TF-SPME, polydimethylsiloxane/carboxene (PDMS/CAR) and PDMS/divinylbenzene (PDMS/DVB), were optimized and compared. To carry out the optimization, a randomized factorial design was performed combining the following factors and levels: extraction mode (headspace (HS), or direct immersion (DI)), stirring speed (500 and 1000 rpm), extraction time (1, 3 and 6 h), and extraction temperature (20, 40 and 60 °C). After performing a principal component analysis (PCA) and an analysis of variance (ANOVA) multifactorial, it was concluded that the best conditions for TF-SPME with PDMS/CAR were: direct immersion (DI), 500 rpm, 6 h, and 20 °C, while for TF-SPME with PDMS/DVB no conditions were found that maximized the extraction of most compounds, therefore compromise conditions were chosen: headspace (HS), 500 rpm, 6 h, and 40 °C. Finally, the comparison between the results obtained with both absorbents indicated that the absorbent that extracted better the volatile compounds from the musts with the TF-SPME technique, was PDMS/CAR, under the conditions: direct immersion (DI), 500 rpm, 6 h, and 20 °C.

Effects of Water Deficit Irrigation on Phenolic Composition and Antioxidant Activity of Monastrell Grapes under Semiarid Conditions.

The high phenolic compound content of grapes makes them an important source of natural antioxidants, among other beneficial health properties. Vineyard irrigation might affect berry composition and quality. Regulated deficit irrigation (RDI) is a widely used strategy to reduce the possible negative impact of irrigation on grapes, improving grape composition and resulting in water savings. Monastrell grapevines (Vitis vinifera L.) grown in eastern Spain were subjected to two water regime strategies: rainfed (non-irrigation) and RDI. The content of anthocyanins, flavonols, flavanols, hydroxybenzoic and hydroxycinnamic acids, and stilbenes was determined by HPLC and was related with total phenolic content and three antioxidant activity methods (ABTS, DPPH, and ORAC). The study aimed to evaluate and compare the phenolic composition and antioxidant potential of Monastrell grapes. The rainfed regime concentrated grapes in terms of phenolic compounds. Thus, total content of anthocyanins, flavonols, flavanols, hydroxybenzoic acids, and total phenols were higher in the rainfed grapes than in the RDI ones. Besides, the rainfed grapes doubled their antioxidant potential with respect to the RDI grapes with the ORAC method. Total phenolic content and antioxidant activity by ORAC assay positively correlated with most of the total phenolic compounds analyzed. This study demonstrates how field practices can modulate final grape composition in relation to their antioxidant activity.

Nanotechnology: recent advances in viticulture and enology.

Nowadays, nanoscience is a leading modern science that has a major impact on the food, pharmaceutical, and agriculture sectors. Several nanomaterials show a great potential for use during vine growing and winemaking processes. In viticulture, nanotechnology can be applied to protect vines against phytopathogens and to improve grape yield and quality. Thus, nanotechnology may allow the use of lesser amounts of phytochemical compounds, reducing environmental impact and promoting a more sustainable agriculture. And in winemaking, nanomaterials and nanodevices can be used to control the growth of spoilage microorganisms and to reduce or remove undesirable compounds, such as ethyl phenols (4-ethylphenol and 4-ethylguaiacol), biogenic amines, and tartaric acid, and so on, as well as to facilitate some technological processes (i.e. in wine filtration to eliminate microorganisms). This review summarizes recent studies with applications of nanotechnology in viticulture in order to facilitate agronomic management and optimize grape production and in enology to improve wine quality and safety. © 2021 Society of Chemical Industry.

Pre-fermentative maceration with SO2 enhanced the must aromatic composition.

SO2 is the additive most used in winemaking, due to its antioxidant and antiseptic activities. There have been several studies focused on these activities; however, there are hardly any studies that address its role as extractant. Therefore, the objective of this work was to study the effect of SO2 on the must volatile composition after a pre-fermentation maceration. The results showed that the influence of SO2 on the extraction of the two most important families of varietal compounds, terpenoids and C13 norisoprenoids, was different: the content of total terpenoids increased by 95%, while for the total of C13 norisoprenoids no significant differences were observed. The other three families of volatile compounds studied, benzenoid compounds, esters, and C6 compounds, were found in greater quantity in the samples with SO2, increasing by 51%, 164%, and 45%, respectively. Consequently, SO2 can enhance the must aromatic composition of neutral varieties, such as Tempranillo.

Effects on must and wine volatile composition after biostimulation with a brown alga to Tempranillo grapevines in two seasons.

BACKGROUND: Seaweed application has been defined as a novel technique capable of improving the content of secondary metabolites in berries. There is limited available information about its effects on must and wine volatile composition. This field trial aimed to study the effects of biostimulation to Tempranillo grapevines through an Ascophyllum nodosum fertilizer applied at a low dosage (Ld) and high dosage (Hd) on must and wine volatile compounds over two seasons. RESULTS: Ld treatment scarcely affected must and wine volatile compounds in both seasons. Hd foliar application increased the content in musts of several individual terpenoids, C13 norisoprenoids, esters, benzenoids, alcohols, carbonyl compounds and C6 compounds in 2018. Must yeast assimilable nitrogen conditioned the production of wine volatile compounds. CONCLUSION: These results suggest that seaweeds applications can act as elicitors in Tempranillo, triggering the synthesis of several compounds by the plant in musts during a season with a high rainfall and relative humidity. © 2020 Society of Chemical Industry.

Advancement in analytical techniques for the extraction of grape and wine volatile compounds.

The grape and wine aroma is one of the most determining factors of quality, therefore the study of their volatile composition is a very important topic in vitiviniculture. The range of concentrations in which many of these compounds are found is quite low, in concentrations of ng/L; due to this, a sample preparation stage is necessary before doing the chromatographic analysis of the volatile compounds. In this review, the main analytical techniques used for the extraction of volatile compounds in grapes and wines are studied. The techniques presented are liquid-liquid extraction (LLE), solid phase extraction (SPE), solid phase microextraction (SPME), stir bar sorptive extraction (SBSE), and thin film solid phase microextraction (TF-SPME). For each of these techniques, a description was made, and the different characteristics were numbered, as well as their main advantages and disadvantages. Furthermore, from the second technique, a comparison is made with the previous techniques, explaining the reasons why new techniques have emerged. Throughout the review it is possible to see the different techniques that have been emerging in the past years as an improvement of the classical techniques.

Phenolic composition of Tempranillo Blanco (Vitis vinifera L.) grapes and wines after biostimulation via a foliar seaweed application.

BACKGROUND: Seaweeds are defined as novel elicitors in many crops, allowing the synthesis of secondary metabolites to be triggered in different plant tissues. Currently, the phenolic composition of Tempranillo Blanco grapes and wines is unreported. The present study aimed to investigate the effects of an Ascophyllum nodosum seaweed extract applied to Tempranillo Blanco grapevines, at low (Ld) and high (Hd) dosages, on grape and wine phenolic compounds during two consecutive seasons (2017-2018). RESULTS: The results obtained showed that catechin was the most abundant phenolic compound in Tempranillo Blanco grapes and wines. Season affected the weight of 100 berries and some enological parameters. Catechin and flavonols concentrations in grapes were increased after Hd application to grapevines, independently of season. The concentration of hydroxycinnamic and hydroxybenzoic acids in wines was affected by vintage, probably as a result of oxidation reactions, as well as pinking phenomena, whereas the stilbenes content in wines was conditioned by the affect of cryptogamic diseases in grapes. CONCLUSION: Seaweeds might act as an elicitor of several phenolic compounds in grapes, enhancing the content of some phenolic compounds in wines. © 2019 Society of Chemical Industry.

Influence of methyl jasmonate foliar application to vineyard on grape volatile composition over three consecutive vintages.

An alternative to improve grape quality is the elicitor application to the vineyard due its implication to induce defense mechanisms involved in the synthesis of secondary metabolites. There are few studies about the influence of elicitors on grape volatile composition. The aim of this work was to investigate the influence of methyl jasmonate (MeJ) foliar application to Tempranillo grapevines on grape aroma composition over three consecutive vintages. In the first vintage, MeJ treatment improved p-cymene, methyl jasmonate, and hexanal synthesis, and degraded 2-hexen-1-ol acetate, (Z)-3-hexen-1-ol, and n-hexanol. In the second season, the content of several terpenes, ß-damascenone, methyl jasmonate, esters, benzenoids and (Z)-3-hexen-1-ol was diminished after MeJ application. In the third vintage, the synthesis of several volatile compounds considered positive contributors for grape aroma was improved by MeJ application. In conclusion, the effect of MeJ foliar application on grape volatile content was mainly dependent on the vintage.