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Polysaccharides are the main group of macromolecules in wines. Climate change is a major problem for viticulturists as it leads to the production of unbalanced grapes. This is attributed to a mismatch between the technological maturity and phenolic maturity of grapes, which can negatively impact the production of high quality wines. To mitigate this effect, biostimulants can be applied to grapevines. For the first time in the literature, this work studied the foliar application of methyl jasmonate plus urea (MeJ + Ur) on the vineyard and its effect on the monosaccharide and polysaccharide composition of Tempranillo grapes and wines over two consecutive seasons. To achieve this, the extraction and precipitation of polysaccharides was conducted, and the identification and quantitation of monosaccharides was performed via GC–MS. The effect of MeJ + Ur foliar treatment in both the grapes and wines was season-dependent. The MeJ + Ur treatment had a slight impact on the monosaccharide composition of the grapes and also demonstrated a small effect on the wines. Multifactor and discriminant analysis revealed that the season had a greater influence on the monosaccharide and polysaccharide composition of grapes and wines compared to the influence of MeJ + Ur treatment. Interestingly, the MeJ + Ur-treated wines exhibited a higher sensory evaluation than the control wines in the second vintage. To gain further insights into the effect of MeJ + Ur foliar application on the monosaccharide and polysaccharide composition of grapes and wines, further investigations should be conducted.

Non-Saccharomyces yeasts, particularly Metschnikowia pulcherrima, are considered alternatives to SO2 in winemaking, combating specific microorganisms. The sensory profile of the wine is contingent upon the type of yeast, the fermentation conditions, and the concentration and mode of application with Saccharomyces cerevisiae strains (whether pure or used in mixed/sequential co-fermentation). This study assessed the aroma in red wines produced with S. cerevisiae (Sc) and M. pulcherrima (Mp, non-Sc), incorporating variations in the method of addition and the inclusion or exclusion of SO2. The enological parameters of the wines were slightly affected. Volatile compounds were analysed in the wines through gas chromatography–mass spectrometry (GC-MS) at three moments: at the end of malolactic fermentation (MLF) and after 6 and 9 months of bottle ageing. Sequential fermentation of Sc and Mp reduced the concentration of most identified alcohols and acids, which is favourable, as these compounds can yield undesirable aromas at high concentrations. Regardless of the yeast mixture and Mp dose, a majority of the acetate esters and ethyl esters were quantified at concentrations above their perception thresholds, thus enhancing the sensory quality of the wines. Sensory analysis of wines showed generally positive evaluations. Using non-Saccharomyces as an alternative to SO2 improves the aromatic profile of wines.

Polysaccharides in wine play important roles in the stabilization and in the sensory properties of wines. Elicitor application constitutes an interesting field of research since it is indirectly involved in the accumulation in grape cell walls of molecules like callose, lignin, phenolic compounds and glycoproteins. Currently, biomimetic calcium phosphate (ACP) nanoparticles are successfully used in viticulture for the controlled delivery of bioactive molecules, such as elicitors. The aim of this study was to compare the effect of the application of two different elicitors on both grape and wine of Tempranillo polysaccharide composition. Methyl jasmonate (MeJ) and nanoparticles doped with MeJ were applied to the canopy at veraison and one week later in two vintages. In the grape extracts, the foliar treatments did not increase the content of monosaccharides or that of the main pectin families; therefore, the elicitors did not reinforce the cell walls of the Tempranillo grape. The extractability and solubility of the pectic families of the grape cell walls into the wine depended on the type of family and the climate of the vintages.

Foliar nutrient sprays are broadly used in commercial agriculture. To date, the application of Ca and Si has been little explored in vineyard production but may lead to positive responses at various levels. Therefore, the aim of this work was to evaluate the effect of supplying single or combined calcium (Ca, 120 mM) and silicon (Si, 120 mM) sprays in Tempranillo grape composition. Foliar treatment with Ca + Si foliar enhanced all families of aromatic compounds, whereas single Ca and Si sprays induced lower effects. Regarding phenolic compounds, all foliar treatments led to minor effects. However, all three foliar Ca and Si treatments increased the total grape amino acid content. Consequently, the application of combined Ca and Si sprays to a vineyard is recommended as a tool for improving grape quality.

Currently, elicitors have been used to induce the defence mechanisms of vines, i.e., against both abiotic and biotic stresses. Besides, increases in phenolic synthesis in grapevines have been reported after elicitors application. However, its effects on the grape nitrogen composition are not entirely known. Thus, this work aimed to study the effect of methyl jasmonate (MeJ) and a yeast extract (YE) applied in Monastrell and Tempranillo grapevines on grape amino acids during two consecutive seasons. Amino acids in grapes were analysed by HPLC. In the first season, the total amino acid content in grapes decreased in Monastrell after MeJ and YE applications from 2236 to 1580 and 1620 mg L-1, respectively, while in Tempranillo, the total amino acid concentration decreased after YE applications from 2355 to 1811 mg L-1. However, during the second season, elicitors did not affect total amino acid concentration. The most important components of variability in amino acid concentration were the grape variety and the season. These results provide new knowledge of the effect of two elicitors in two important red varieties on grape amino acids content, relevant for wine quality.

Methyl jasmonate (MeJ) is an elicitor that, when applied in the vineyard, can improve grape quality. There are several studies about the MeJ influence on red grape varieties; however, to our knowledge, there is little information about white grape varieties, specifically Tempranillo Blanco. Therefore, the aim of this work is to evaluate the effect of MeJ foliar treatments, carried out at veraison and post-veraison, on the aromatic, phenolic and nitrogen composition of Tempranillo Blanco grapes. The results showed that grape volatile compounds content increased after MeJ application, especially terpenoids, C13 norisoprenoids, benzenoids and alcohols, and, in general, mainly at post-veraison. Regarding phenolic and nitrogen compounds, their concentrations were enhanced after MeJ treatments, regardless of application time. Consequently, MeJ treatment improved grape volatile, phenolic and nitrogen composition, particularly when this elicitor was applied post-veraison. Therefore, this is a good and easy tool to modulate white grape quality.

Foliar application has been studied to enhance grape composition and, therefore, wine quality. This work examined, for first time, the effects of foliar applications of methyl jasmonate (MeJ) and methyl jasmonate plus urea (MeJ+Ur) to Tempranillo vineyard on wine phenolic, aromatic and nitrogen composition over two vintages (2019 and 2020). A reduction in alcoholic degree was observed in MeJ and MeJ+Ur wines. The effect of foliar treatments was season-dependent. MeJ and MeJ+Ur wines were characterized, in the first vintage, by a higher content of total acylated anthocyanins, but a low content of total esters, alcohols and acids when compared with control wines. MeJ+Ur wines presented a higher total amino acids content than control and MeJ wines. However, in the second vintage, MeJ and MeJ+Ur wines presented an increase in some non-acylated anthocyanins, but only MeJ+Ur treatment increased the total content of flavonols, flavanols, hydroxycinnamic acids, stilbenes and total amino acids when compared with control wines. MeJ wines presented a low content of esters and acids, whereas MeJ+Ur did not show differences with control wines. Overall, the effect of MeJ+Ur foliar treatment was greater than the effect of MeJ application in order to improve the wine chemical composition.

The phenolic, aromatic and nitrogen composition of a wine determines its organoleptic profile and quality. Elicitors have been used as a tool to stimulate the plant’s defense systems, favoring the synthesis of secondary metabolites. In this pioneering study, the elicitor methyl jasmonate in conventional form (MeJ) and in nanoparticle form (ACP-MeJ), with a concentration ten times lower, was applied in a Tempranillo vineyard over two seasons. The phenolic, nitrogen and volatile composition and the sensory properties of the MeJ-based wines were determined. The results showed that the effects of foliar applications of MeJ modify the wine composition. Thus, although the total concentration of most of the groups of phenolic compounds was not altered, several compounds, such as petunidin-3-glucoside, quercetin-3-glucoside, epigallocatechin and most of the stilbenes, increased, in both years, in the treated wines. Amino acids were influenced differently in each of the years studied, and volatile compounds generally did not improve in the treated wines. However, the ACP-MeJ wines were the best rated by the tasters, highlighting their equilibrium on the taste and their genuineness and odor quality. Therefore, foliar applications of ACP-MeJ can be considered a useful tool to improve wine quality.

Aim: An oxidation process frequently occurs during white winemaking, affecting its quality. The aim was to study, for two years (2013 and 2014), the effects that foliar applications of vine-shoot (Airén (AVS) and Moscatel (MVS)) and oak wood (OW) extracts on Airén grapevines have on wine color, and must and wine glutathione, trans-GRP, trans-caftaric acid, and trans-p-coutaric acid content. Methods and results: These compounds were analyzed by HPLC. The results showed that, in general, foliar application of Airén vine-shoot extracts did not affect glutathione concentration, and the other treatments decreased it. AVS2013-50 and AVS2014 samples were characterized by a high content of glutathione and trans-GRP, while MVS2014 samples retain high levels of trans-caftaric acid. trans-p-Coutaric acid concentration decreased after AVS2013 treatment, meanwhile in the 2014 season all applications increased its content. The content of these compounds in the wines was similar to those obtained in the musts. OW2013 showed the lowest value of Abs 420, likely because this treatment decreased glutathione concentration in musts. Conclusions: The foliar applications of vine-shoots and oak extracts on Airén grapevines had a clear effect in reducing the wine alcohol degree and Baumé in case of grapes. This finding is interesting in the context of the current global warming change scenario. Although the two vintages studied were different, an improvement in the color quality was observed in both. The content of glutathione decreased from must to wine: the content in both matrices was lower in treated samples than in control samples, except for Airén extracts in both vintages. This means that glutathione is oxidized, avoiding the oxidation of other must and wine molecules. Significance and impact of the study: These findings are important in relation to revalorizing waste from the vineyard, and thus being able to improve the quality of the white wine in relation to the oxidation processes that take place in the winemaking process.

Volatile and phenolic compounds play a key role in the sensory properties of wine, especially aroma and color. During fermentation, yeasts produce enzymes that affect the skin’s phenolic compounds extraction and synthesize some of the most important wine volatile compounds. Generally, selected yeasts of the Saccharomyces cerevisiae (Sc) strains are inoculated, which are responsible for carrying out the wine fermentation, enhancing and highlighting its sensory characteristics and contributing to help achieve the wine typicity, according to the winemaker’s criteria. After fermentation, all wines require aging in a bottle to modulate their composition and stability over time. Thus, four different Sc strains (Sc1–Sc4) were inoculated into tanks with Tempranillo grapes to carry out, in duplicate, their fermentation and subsequent aging in bottles (9 months), comparing the aromatic and phenolic composition between them. Results showed differences in the fermentation process (kinetic, ethanol yield), CI, TPI and content of alcohols, esters, anthocyanins, flavonols and flavanols in wines from the different Sc strains studied. Moreover, in the content in wines of most groups of aromas and phenols, except for total acetate esters and flavonols, aging in a bottle had more influence than the yeast strain used for fermentation.

The aim of this work was to analyze and compare the concentration of higher alcohols, esters, and acids in wines from Tempranillo and Tempranillo Blanco. Tempranillo Blanco is a new and little-studied white variety that originated from Tempranillo by a natural mutation. During three seasons, grapevines of both varieties were harvested, and nine wines were made from each. The volatile composition of the wines was determined by GC-MS. In the wines of both varieties, the content of higher alcohols was higher than those of esters and acids. Wines from Tempranillo Blanco had lower content of 2-phenylethanol, methionol, 1-hexanol, benzyl alcohol, and total higher alcohols, but higher hexyl acetate and ethyl decanoate than Tempranillo wines. Total ethyl esters and total esters were higher in Tempranillo wines due to the higher ethyl lactate and ethyl succinate content derivate from the malolactic fermentation that was not made in Tempranillo Blanco. The content of hexanoic and octanoic acids and total acids was also higher in Tempranillo Blanco wines than in Tempranillo. This is one of the first studies carried out on the wine volatile composition of Tempranillo Blanco and therefore contributes to a better understanding of the oenological characteristics of this white variety.

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.

The production of edible mushrooms presents a serious problem for the environment, since about 5 kg of waste are produced for each kilogram of mushroom. These waste waters have nitrogenous matter. Thus, the aim was to investigate the effect of foliar applications of waste water from the mushroom production process on must amino acid composition during two seasons compared to other nitrogen sources. The treatments were applied to the vineyard at veraison and one week later at a total dose of 0.9 kg N/ha. Amino acids were analysed by HPLC. Results showed that treated mushroom water (Tmw) and mushroom water (Mw) improved the amino acid concentration in both seasons differentially. Tmw applied to the grapevines increased total amino acids concentration from 1479.58 to 1735.90 mg/L compared to untreated grapevines over the second study season. The effectiveness of the applications depends on grapevines nitrogen needs. Under moderate nitrogen conditions, Tmw and Mw applications seem to be more effective than urea and phenylalanine treatments. These results are important in relation to the sustainable management of the agri-food sector.

Tillage and semiarid Mediterranean climatic conditions accelerate soil organic matter losses in Spanish vineyards. Previous studies showed that cover crops can increase soil organic carbon (SOC) in Mediterranean vineyards. The objectives of this study were to evaluate the influence of two different cover crops in the short term on soil C sequestration in a semiarid vineyard and to study the potential use of both β–glucosidase enzimatic activity (GLU) and the GLU/SOC ratio in order to assess the SOC increase. The experiment was carried out in a cv. Tempranillo (Vitis vinifera L.) vineyard on a Oxyaquic Xerorthent soil in Rioja winegrowing region (NE, Spain). The experimental design was established in 2009 with three treatments: conventional tillage; sown barley cover crop (Hordeum vulgare, L.); sown Persian clover cover crop (Trifolium resupinatum L.). Carbon in the aboveground biomass with each cover crop was monitored. Soil was sampled in June 2011 and June 2012, and SOC, GLU and the GLU/SOC ratio were determined. After 3 years both cover crops increased SOC at soil surface with C sequestration rates of 0.47 and 1.19 t C ha-1 yr-1 for BV and CV respectively. GLU and GLU/SOC ratio increased in both cover crops at 0-5 cm soil depth. The C sequestration rates and GLU were related to the cover crops aboveground biomass. In consequence, in semiarid vineyards under cover crops GLU could be an appropriate indicator to asses the increase of SOC and the soil quality improvement in the short-term (2-3 years).