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The effects of foliar application of methyl jasmonate and methyl jasmonate plus urea on the amino acids content of Tempranillo grapes were evaluated during two seasons (2019 and 2020). In 2019, the foliar treatments favored an increase in ammonium nitrogen (N), amino N and yeast assimilable N when compared to the control grapes; whereas, in 2020, treatments did not affect N parameters in grapes. In 2019, foliar application of both treatments was effective in improving amino acids content in grapes, being significantly higher the effect of methyl jasmonate plus urea treatment than methyl jasmonate treatment. However, in 2020, the effect of both treatments on amino acid content was minor. The different effect among seasons could be explained by environmental conditions and by the differences in N content in grapevines. A multifactorial analysis and discriminant study were carried out, showing that both treatments enhanced amino acid content in grapes. The effect of methyl jasmonate plus urea was stronger than the effect of methyl jasmonate treatment. Also, a great effect of season on amino acids composition was observed. [ABSTRACT FROM AUTHOR]

Pulsed electric fields effect was studied on the physico-chemical and general phenolic composition as colour characteristics and stilbene content in must and wine. For this purpose, a continuous pulsed electric fields equipment was used to treat three red grape varieties of DOCa Rioja. Graciano, Tempranillo and Grenache wines from these grapes were elaborated with different maceration times, 2 days in the untreated sample (control) and the PEF-treated sample (PEF), and normal maceration time in another untreated sample (control-NM). Parameters as colour intensity, anthocyanin content, total polyphenol index and tannin content showed no differences between the PEF sample with 2 days of maceration and the control-NM sample, except in the case of Tempranillo wines. Total stilbenes, trans-resveratrol and trans-piceid of Graciano wines elaborated from PEF samples showed a higher concentration than the control wines. Alternatively, PEF wines and control-NM wines showed no differences between them. Tempranillo variety wines presented no differences between the three types of samples. In the Grenache variety, only trans-piceid levels showed differences between control and PEF wines. Moreover, relationship between must and wine characteristics was evaluated and compared between different samples. The trend lines obtained for the CI, TPI and AC parameters for samples of Graciano, Tempranillo and Garnacha indicate that the initial content of compounds extracted significantly affected the days of maceration necessary to obtain the appropriate wine. The results obtained increase the knowledge of pulsed electric fields as a technology available for use in the winery to elaborate red wines with reduced maceration time. [ABSTRACT FROM AUTHOR]

Grape volatile compounds determine the wine quality and typicity. The aim of this work was to study the effects of several foliar applications in 'Garnacha', 'Tempranillo', and 'Graciano' grapevines in order to enhance their grape volatile composition. The field trial involved the application of two nitrogen compounds, urea (Ur) and phenylalanine (Phe), and two elicitors, methyl jasmonate (MeJ) and a yeast extract (YE). The analysis of grape volatile compounds was carried out by HS-SPME-GC-MS. For 'Garnacha', most terpenes, and C13 norisoprenoids increased their grape content by applying Ur and Phe, and especially MeJ. For 'Tempranillo', treatments with Ur and MeJ improved the synthesis of most terpenoids. For 'Graciano', a trend to decrease the terpenoids content in grapes with the treatments was observed; however, Phe application increased C13 norisoprenoids content. In conclusion, foliar application of, Phe or Ur, and an elicitor, MeJ, can be a useful tool to improve grape quality. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the influence of foliar applications of different wood aqueous extracts on the amino acid content of musts and wines from Airén variety; and to study their relationship with the volatile compounds formed during alcoholic fermentation. For this purpose, the foliar treatments proposed were a vine-shoot aqueous extract applied in one and two times, and an oak extract which was only applied once. Results obtained show the potential of Airén vine-shoot waste aqueous extracts to be used as foliar fertilizer, enhancing the wine amino acid content especially when they were applied once. Similar results were observed with the aqueous oak extract. Regarding wine fermentative volatile compounds, there is a close relationship between musts and their wines amino acid content allowing us to discuss about the role of proline during the alcoholic fermentation and the generation of certain volatiles. [ABSTRACT FROM AUTHOR]

• Innovative nanoparticles doped with methyl jasmonate were applied to Tempranillo. • Season had higher impact on the grape phenolic compounds than the applied treatments. • MeJ treatment promotes anthocyanin but not flavonol and flavanol synthesis in grapes. • ACP-MeJ slow release could favor the increase of flavonols, flavanols and stilbenes. • Nano MeJ application increase some phenolic compounds and reduce environmental impact. Tools to address the mismatch between technological and phenolic maturity of grapes are needed. Application of elicitors could be an effective alternative. This work compares the effect of the application of methyl jasmonate (MeJ) in conventional form and, as a novelty, in the form of MeJ-doped nanoparticles (ACP-MeJ) on the phenolic composition of Tempranillo grapes. Results showed that, regardless of season, both treatments increased the grape total phenols content. In 2019, most of the anthocyanins, and to a lesser extent the flavanols, increased with the application of MeJ, and several hydroxycinnamic acids increased in the grapes treated with ACP-MeJ, with dose 10 times lower than those of the MeJ conventional. In 2020, anthocyanins were not affected by the treatments, but total flavanols, flavonols, hydroxybenzoic acid, and stilbenes increased after ACP-MeJ application. Thus, foliar application of ACP-MeJ could serve to increase grape phenolic composition, reducing maturity decoupling and the environmental impact. [ABSTRACT FROM AUTHOR]

• First work of phenolic composition after seaweed application to Tempranillo vineyard. • Ascophyllum nodosum extract foliar application at two dosages in two seasons. • Seaweed treatements improved grape stilbenes concentration. • However, its effect on the rest of phenolic compounds content depended on the vintage. The study of seaweeds is increasing in viticulture due to their implications on plant protection and grape quality. This trial aimed to study the effects of foliar applications of an Ascophyllum nodosum extract at low (0.25%, v v−1) and high (0.50%, v v−1) dosages on grape and wine phenolic compounds in 2017 and 2018. In grapes, seaweed biostimulation increased the content of malvidin-3-glc, myricetin-3-glc and myricetin-3-gal in 2017 season. Moreover, both treatments improved the synthesis of trans -piceid and total stilbenes in both seasons. Sensory analysis revealed that 2017 wines had more color than the 2018 wines, which coincided with color intensity parameters. Therefore, seaweed applications to grapevines improved stilbenes content in grapes independently of the season and its effects on the rest of phenolic compounds in grapes and wines depended strongly of season factor. [ABSTRACT FROM AUTHOR]

• First study about nitrogen composition after seaweed application to Tempranillo vines. • Low dosage of the treatment increased the content of amino acids in grapes in 2017. • High dosage of the treatment increased the grape content of some amino acids in 2018. • Must nitrogen composition limited wine amino acids content rather than the treatments. There is little available information about the effects of seaweed biostimulation to grapevines on grape juice and wine nitrogen content. This trial aimed to study the effects of the biostimulation through an Ascophyllum nodosum fertilizer to Tempranillo grapevines at low (Ld: 0.25 % v v−1) and high (Hd: 0.50 % v v−1) dosages on must and wine amino acids and ammonium during two seasons. The content of these compounds in musts and wines were measured by UHPLC. The results showed that precipitations could have affected berry size and enological parameters of musts and wines. In the driest season (2017), Ld treatment increased the concentration of several amino acids in musts such as His, Arg, Ala, Gaba, Pro, Val, Met, Ile, Trp, Orn, Lys, and total amino acids. In the rainiest season (2018), the Hd treatment was the most effective, increasing the content of His, Cit + Thr, and Trp. Generally, a high yeast assimilable nitrogen (> 279.4 mg N L-1) content in the must allowed to reach a high concentration of amino acids in wines. Therefore, seaweed foliar application to grapevines allowed to improve amino acid content in musts in both seasons and its effectiveness depended of climate conditions of the season and the dosage applied. [ABSTRACT FROM AUTHOR]

• First study about volatile composition of Tempranillo Blanco grapes. • C 13 norisoprenoids were the most abundant varietal aroma compounds in grapes. • Seaweed applied to grapevines increased the content of certain C6 compounds in grapes. • Seaweed applications to grapevines tended to decrease wine volatile compounds in 2018. • Season affected grape and wine volatile compounds after seaweed applications to vines. The effects of seaweed applications to grapevines on grape and wine volatile composition are currently unknown. The aim of this work was to study the influence of seaweed foliar applications (Ascophyllum nodosum) to a Tempranillo blanco vineyard on grape and wine volatile composition. A low (Ld) and a high dosage (Hd) of the seaweed fertilizer was applied in two consecutive seasons (2017–2018). The most abundant family of varietal volatile compounds in Tempranillo blanco grapes was C 13 norisoprenoid. Hd treatment tended to increase the concentration of certain C6 compounds in grapes in both seasons, whereas Ld application tended to decrease 2-phenylethanol and 2-phenylethanal content in grapes with a season dependence. Season factor affected to the concentration of most of the volatile compounds in grapes due to the differences on rainfall, which affected to the weight of 100 berries and physico-chemical parameters. Yeast assimilable nitrogen (YAN) in musts could have affected the concentration of most of the wine volatile compounds. According to odor activity values (OAV), Tempranillo blanco wines were characterized as floral, fruity, banana, pear, among others aroma compounds. [ABSTRACT FROM AUTHOR]

• First study about NH 4 + and amino acids content in Tempranillo blanco musts and wines. • First study about the effects of Ascophyllum nodosum biostimulation on this variety. • Tempranillo blanco behaved as arginine accumulator variety. • High dose (Hd) of seaweed was positively correlated with amino acids in both seasons. • Season was the most important variability factor of amino acids in grapes and wines. Recently, A.O.C. Rioja have selected and enlisted the Tempranillo blanco as a new grapevine variety to be cultivated in this area. This is the first report that studies amino acid and ammonium composition of grape juice and wine from Tempranillo blanco. The aim was to study the effect of foliar application of a seaweed extract to a Tempranillo blanco vineyard on must and wine amino acids and ammonium content. The results suggested that Tempranillo blanco behaved as an arginine accumulator variety. Biostimulation after seaweed applications at a high dosage (Hd) to the grapevines increased the concentration of several amino acids in the 2017 season, while scarcely affected their content in 2018. Phenylalanine, precursor of several volatile and phenolic compounds, was increased in both seasons after Hd applications. Season was the most important factor in the variability of the must and wine amino acids concentration, followed by treatment and its interaction. [ABSTRACT FROM AUTHOR]

Light is an energy source and key environmental factor for plants. Out of the different light wavelengths, blue-light is one of the most relevant spectral regions because of its relation to anthocyanins biosynthesis. Among the compounds present in grapes, anthocyanins determine their main organoleptic and healthy properties; while a minimum concentration of ammonium and amino acids is necessary for a desirable development of the alcoholic fermentation. Moreover, amino acids are precursors of several volatile compounds synthetized during the fermentation. The aim of this study was to assess the influence of riboflavin (vitamin B2) applications, at harvest and one week later,to grapevine leaves in combination with post-harvest blue-light irradiation on Tempranillo (Vitis vinifera L.) grape anthocyanins and amino acidscomposition. The combination of blue-light irradiation and two riboflavin doses as well as theseindividual factors affected both grape anthocyanins and amino acidsconcentrations. After one week of storage, anthocyanins concentration diminished when clusters were irradiated with blue-light; while for amino acids content, the trend to increase or decrease is dependent on the riboflavin dose applied in vines and the storage time. Unlabelled Image • The 2 doses of riboflavin (0.5 and 1 mM) applied in vines increased grape amino acid concentration. • At harvest, the content of five anthocyanins was affected by riboflavin application. • Grape anthocyanins content decreased after one week of blue-light irradiation. [ABSTRACT FROM AUTHOR]

Highlights • The effect of elicitation on grape volatile composition had been little studied. • 3 elicitors were assayed: methyl jasmonate-MeJ, chitosan-CHT, a yeast extract-YE. • Sum of terpenes, C 13- norisoprenoids, benzenoids and esters was the lowest in MeJ and CHT. • Total C6 compounds content in grapes treated with MeJ and CHT was the highest. • YE application scarcely affected volatile compounds respect to control samples. Abstract Elicitors play a key role against pathogen infestation, becoming as an alternative to chemical pesticides by the improving secondary metabolites synthesis. Their effect on grape volatile compounds has been little investigated. This field trial aimed to study the foliar application of methyl jasmonate (MeJ), chitosan (CHT), and a yeast extract (YE) on grape volatile compounds by HS-SPME-GC–MS. The results showed that, in general, foliar elicitor application decreased the synthesis of grape volatile compounds. Depending of the treatment, MeJ and CHT showed the lowest total amounts of terpenoids, C 13 norisoprenoids, benzenoids, and esters, together with the highest levels of C6 compounds. YE treatment applied to the grapevines barely affected the synthesis of volatile compounds in grapes. The importance of this work is to add information about the effects of elicitors on grape volatile composition in Tempranillo grapevines. [ABSTRACT FROM AUTHOR]

Nitrogen compounds play a key role on grape and wine quality. Their composition in grapes depends mainly on variety, viticultural management, and terroir, and affects fermentation kinetics and the volatile compound formation. The aim of this work was to study grape and wine amino acid composition of ungrafted or grafted onto cv. País Carignan grapevines growing under rainfed conditions in ten sites of the Maule Valley (Chile). The results showed that proline was the most abundant amino acid in grapes and wines. In general, Carignan noir grapevines grafted over País showed lower grape amino acid content respect to ungrafted vines. Cool night index (CI) was inversely correlated to several amino acids, showing that their plant synthesis or accumulation increased with lower minimum temperatures during the last month before harvest. Truquilemu (Tru) and Ciénaga de Name (Cdn) sites showed the highest concentration for several amino acids and total amino acid content in grapes, which led to a faster alcoholic fermentation. [ABSTRACT FROM AUTHOR]

Elicitors play an important role in the defense against pathogens as an alternative to chemical pesticides by increasing secondary metabolites. Their effect on grape amino acid has been little investigated. Thus, the aim of this research was to study the influence of methyl jasmonate (MeJ), chitosan (CHT), and a yeast extract (YE) on grape amino acid composition, through foliar applications to grapevines. The must amino acid concentration was analyzed by HPLC. The results showed that CHT and YE treatments decreased the must concentration of several amino acids, affecting total amino acid content (from 2364 to 1961, and 1818 mg/L, respectively). However, MeJ treatment had a slight effect on grape amino acid content, increasing the concentration of Met (from 8.95 to 12.13 mg/L) and Phe (from 7.96 to 9.29 mg/L). It seems to be that, the resistance induction through CHT and YE treatments results in physiological costs to grapevines associated with a decrease on grape amino acid concentration. Consequently, MeJ applications, as a viticultural practice, could be a better tool than CHT and YE treatments, because did not affect grape amino acid concentration. [ABSTRACT FROM AUTHOR]

• The first time that methyl jasmonate-doped nanoparticles (Ap-MeJ) were used in vine. • Foliar application of Ap-MeJ under rainfed and RDI regime: effect on N compounds. • Season and water regime affected more the amino acids content than foliar treatments. • Musts from rainfed regime had higher amino acids content than those from RDI. • Musts from Ap-MeJ treatment and rainfed regime increased certain amino acids content. In viticulture, the application of elicitors to the grapevines is increasing although their effect on the amino acids content is little studied. In this work, nanoparticles of methyl jasmonate (Ap-MeJ) were applied for the first time to Monastrell grapevines during two seasons (2019 and 2020) to increase its profitability and nitrogen plant uptake and to reduce environmental impact (less quantity) and increase its economic viability. In addition, rainfed plants were compared with grapevines under regulated deficit irrigation (RDI) watering regime, since global climatic conditions are limiting water use and quality. Results showed that season was the factor that most affected to the amino acids content (values of 12 from the 21 free amino acids determined were higher in 2019 and 4 in 2020), followed by the watering regime (higher amino acids content in musts from rainfed than in RDI water status). Foliar treatments had little impact on grape enological parameters, as well as on the amino acids concentration (only content of Pro was higher in control than in Ap-MeJ musts). This preliminary study could not confirm the elicitor effect of MeJ loaded on nanoparticles on must amino acid content and further research work should be performed in order to optimize dose of application. [ABSTRACT FROM AUTHOR]