Effects of foliar application of methyl jasmonate and/or urea, conventional or via nanoparticles, on grape volatile composition

Research Article Received: 28 October 2023 Revised: 9 May 2024 Published online in Wiley Online Library: (wileyonlinelibrary.com) DOI 10.1002/jsfa.13660 Effects of foliar application of methyl jasmonate and/or urea, conventional or via nanoparticles, on grape volatile composition Lesly L. Torres-Díaz,aEva P Pérez-Álvarez,a * Belén Parra-Torrejón,b Sandra Marín-San Román,aItziar de Sáenz de Urturi,a Gloria B Ramírez-Rodríguez,bRebeca Murillo-Peña,a Miriam González-Lázaro,aJosé M Delgado-Lópezband Teresa Garde-Cerdána * Abstract BACKGROUND: Viticulture has adapted foliar applications of biostimulants as a tool to improve crop quality. Recently, nanotechnology has been incorporated as a strategy to reduce the loss of biostimulants and treat nutrient deficiencies. Therefore, the present study aimed to investigate the effect of foliar applications of amorphous calcium phosphate nanoparticles (ACP) doped with methyl jasmonate (ACP-MeJA) and urea (ACP-Ur), individually or together (ACP-MeJA+Ur), on the content of volatile compounds in ‘Tempranillo’grapes, compared to the conventional application of MeJA and Ur, individually or in combination (MeJA+Ur). RESULTS: The results showed that nanoparticle treatments reduced the total C6 compounds and some carbonyl compounds in the grape musts. This is of novel interest because their presence at high levels is undesirable to quality. In addition, some aroma-positive compounds such as nerol, neral, geranyl acetone, ⊎-cyclocitral, ⊎-ionone, 2-phenylethanal and 2-phenylethanol increased, despite applying MeJA and Ur at a lower dose. CONCLUSION: Consequently, although few differences in grape volatile composition were detected, nanotechnology could be an option for improving the aromatic quality of grapes, at the same time as reducing the required doses of biostimulants and generating more sustainable agricultural practices. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Keywords: grape; methyl jasmonate; nanoparticles; ‘Tempranillo’; urea; volatile compounds INTRODUCTION Both viticulture and winemaking are essential practices representing a critical economic activity in numerous regions worldwide. In 2020, the global vineyard area exceeded 7.3 million hectares, with Spain covering the largest vineyard acreage. 1 ‘Tempranillo’, a widely cultivated red grape variety in Spain, stands out as the quintessential variety in the Rioja region. It is characterised by its versatility because it adapts to different soils and climatic conditions. 2 The wines elaborated from this grape variety are characterised by aromas evoking forest fruits, plum, strawberry and wildflowers. Aroma plays a pivotal role in the character and quality of wine and is primarily influenced by the grape's composition. 3 In the present study, primary aromas were studied, which in turn are classified as varietal and prefermentative aromas, encompassing various compounds families, such as terpenoids, C 13 norisoprenoids, C6 compounds, alcohols, esters, benzenoids and carbonyl compounds. 3-5 Grape quality is predominantly conditioned by climate, agronomic practices, soil type and grape variety. 6-8 The climate is undoubtedly a critical factor in all agricultural systems; its influence is much more notable in viticulture and, thus, in winemaking. Although grapevines exhibit adaptability to different climatic conditions, and are resistant to moderate heat and water *Correspondence to: E P Pérez-Álvarez or T Garde-Cerdán, Grupo VIENAP, Instituto de Ciencias de la Vid y del Vino (CSIC, Gobierno de La Rioja, Universidad de La Rioja). Ctra. de Burgos, km. 6. 26007 Logroño, Spain. E-mail: evapilar. [email protected] (Pérez-Álvarez); [email protected] (Garde-Cerdán) aGrupo VIENAP, Instituto de Ciencias de la Vid y del Vino (CSIC, Gobierno de La Rioja, Universidad de La Rioja), Logroño, Spain bFacultad de Ciencias, Departamento de Química Inorgánica, Universidad de Granada, Granada, Spain © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. 1 stress, they are susceptible to severe stress by extreme weather events. 9 The climate change causes a mismatch between technological and phenolic maturities, which affects grape and wine quality. Moreover, agronomic practices, such as leaf removal, cluster thinning and soil fertilisation, can also influence the synthesis of primary and secondary metabolites, and therefore modify the grape aromatic composition. To mitigate environmental effects and prevent nutritional wastage and deficiencies, alternative techniques have been proposed. 10 These include the foliar application of biostimulants to the vineyard because of the rapid and efficient use by plants of the applied products. Some of the advantages obtained from this technique are the reduction of costs and the contribution to sustainable and environmentally friendly ecological agriculture. 4,11-13 The biostimulants used in the present study were methyl jasmonate (MeJA) and urea (Ur). MeJA has been used in recent years as a defence agent against pathogens and as a strategy to stimulate the synthesis of secondary metabolites in plants, as well as to extend the shelf life and improve the quality of food during harvest and storage. 14-21 Currently, urea fertilisers account for the majority of the world's nitrogen fertiliser applications because of their high nitrogen concentration and low costs. 22 However, some disadvantages have been reported in the use of biostimulants, especially MeJA, which is expensive, has low water solubility and is highly volatile 21,23,24 and, in addition, several applications are necessary to achieve an effect. 21,24 Urea traditionally has been economic. However, the international association of fertiliser manufacturers announced the rise in prices of this product as a result of the record prices that were to be reached in natural gas in Europe. 25 Hence, nanotechnology is opening up as an alternative to improve plant nutrition, reduce the loss of nutrients in crops and limit unwanted environmental effects, 26 in addition to striving to maintain the balance between doses/benefits. 21,24,27 Although the use of this type of materials in agribusiness has been suggested, their application in viticulture is relatively recent compared to other agri-food sectors. 28 In this context, Garde-Cerdán et al. 21 reported that the application of MeJA and MeJA-doped nanoparticles in ‘Tempranillo’variety increased the content of some anthocyanins, flavonols, flavanols and non-flavonoid compounds compared to the control treatment, highlighting the potential of employing MeJA-doped nanoparticles to enhance the phenolic composition of grapes, as well as reducing maturity decoupling and the environmental impact. Furthermore, Gimenez-Bañón et al. 29 investigated the impact of MeJA-doped nanoparticles on the volatile composition of ‘Monastrell’wines over three seasons, reporting that nanoMeJA treatment generally increased the volatile composition to a similar degree to that obtained with conventionally used MeJA, but at a dose that was 10 times lower. Marín-San Román et al. 30 found that MeJA application increased the concentration of terpenoids, C 13 norisoprenoids and total C6 compounds, whereas amorphous calcium phosphate nanoparticles (ACP)-MeJA enhanced the amount of terpenoids, and benzenoid compounds. Pérez-Álvarez et al. 31 managed to increase the amino acids content in ‘Tempranillo’grapes after foliar application of nanoparticles doped with urea and underscored that the use of nanoparticles could reduce the dose of fertiliser. In the same way, Gil-Muñoz et al. 23 reported that the conventional application of MeJA and nanoparticles doped with MeJA increased the concentration of amino acids in ‘Monastrell’grapes, although better results were found when applying the biostimulants doped to the nanoparticles. Parra-Torrejón et al. 24 designed amorphous calcium phosphate nanoparticles doped with MeJA aiming to increase the content of stilbenes in wine. In addition, these lower cytotoxicity was reported when using MeJA on nanoparticles, characteristics that are important for the use of biostimulants more safely and efficiently in agribusiness. ACP are materials analogous to the materials that make up the bone structure of mammals. 32,33 This type of material has gained significant interest in agribusiness because of its composition, mainly calcium and phosphorus, two essential nutrients for plants; its high surface reactivity, which gives it the ability to be doped with different ions and biomolecules; its biodegradability and biocompatibility; and its shape and size, which are also an advantage because they allow easier penetration into plants. 33-35 Considering the notable benefits that have been achieved with the use of urea and MeJA to improve the quality of grapes, there is the question of whether applying MeJAand Ur-doped nanoparticles (ACP-MeJA: 1 mM; ACP-Ur: 0.4 kg N ha −1 ) has the same effect as applying them conventionally. Furthermore, is it possible to improve the grape volatile composition by exogenously applying nanoparticles doped with MeJA and/or Ur? What are the effects on the aroma composition of grapes of applying MeJA and/or Ur individually and in combination? It is worth noting that there are no studies about the use of these two biostimulants together, either freely or in combination, in the composition of grapes, and no research has investigated the effect of urea supported in nanoparticles on the aromatic composition of grapes of the ‘Tempranillo’variety. Considering the above, it is possible that nanoparticles doped with one of the biostimulants improve the volatile composition of ‘Tempranillo’grapes, or, failing that, give similar results as when MeJA and/or Ur are applied in a conventional way. Therefore, the present study aimed to compare the effect of foliar application of MeJA and/or urea, conventionally and in apatite nanoparticles, applied both individually and together, on the volatile composition of ‘Tempranillo’grapes. MATERIALS AND METHODS Vineyard site and experimental design ‘Tempranillo’(Vitis vinifera L.) variety grown in a commercial vineyard in Monte Cantabria, Logroño, La Rioja (North of Spain) was employed for this trial, in the 2021 vintage. The vineyard (latitude 42°28´48.7700 N; longitude 2°2600.400 W) is 492 m above sea level, with a planting density of 2922 plants ha −1 , and with distances of 3 m between rows and 1.2 m between vines. The vines were trained on a single vertical trellis system, were pruned leaving four to five thumbs (two buds per thumb) per plant and grown in rainfed conditions using traditional cultural practices in D.O.Ca. Rioja. The site has a semi-arid continental Mediterranean climate, with warm and dry summers and the rainfall period concentrated mainly at spring. The work involved the foliar application of the following seven treatments: control (water), conventional methyl jasmonate solution (MeJA, 10 mM), ACP loaded with MeJA (ACP-MeJA, 1 mM), urea solution (Ur, 6 kg N ha −1 ), ACP loaded with urea (ACP-Ur, 0.4 kg N ha −1 ), MeJA and urea (MeJA+Ur, 10 mM+6kgNha −1 ) and ACP loaded with MeJA and Ur (ACP-MeJA+Ur, 1 mM + 0.4 kg N ha −1 ). Urea and MeJA are commercial products (Sigma-Aldrich, Madrid, Spain). ACP-Ur and ACP-MeJA were prepared according to the methodology described elsewhere. 21,24,31,35 For preparation of nanoparticles loaded with the two molecules, ACP-MeJA+Ur, first, ACP nanoparticles were synthesised by mixing two solutions of equal volume (2 L): (i) an www.soci.org LL Torres-Díaz et al. wileyonlinelibrary.com/jsfa © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. J Sci Food Agric 2024 2 10970010, 0, Downloaded from https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.13660 by Universidad De Granada, Wiley Online Library on [19/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License aqueous solution containing 0.2 mol L −1 calcium chloride and 0.2 mol L −1 sodium citrate and (ii) an aqueous solution containing 0.12 mol L −1 dipotassium phosphate and 0.1 mol L −1 sodium carbonate. After 5 min, the ACP precipitate was collected and repeatedly washed with ultrapure water by centrifugation (3428 ×gfor 15 min). Subsequently, ACP nanoparticles were dispersed in 1.5 L of a 4.3% m/v urea solution and then 4 mL of methyl jasmonate was added to the solution. The mixture was left under agitation for 24 h and then ACP-MeJA+Ur nanoparticles were collected by centrifugation as described before and stored at room temperature. MeJA and urea loading was quantified by UV-visible spectroscopy and elemental analysis, respectively, as previously described. 24,35 The experimental design was carried out in randomised blocks with seven treatments, in triplicate (7 ×3=21 trials), with five vines per replicate (105 plants in total). For each plant, 200 mL of solution (this volume is sufficient to cover a medium-sized vine, and thus avoid wasting biostimulant through dripping) were applied twice, at veraison and 1 week later on. To perform the treatments, aqueous solutions were prepared using Tween 80 (Sigma-Aldrich) as wetting agent (1 mL L −1 ). Measures taken to prevent any cross-media effects arising from the application of the foliar treatments under investigation, applications of the treatments were made by alternating the rows, suggesting that the treatments were applied in one row and then not in the next, rather than continuously. According to the methodology of Garde-Cerdán et al., 36 grapes were hand-harvested at their optimum point of technological maturity, such that the weight of 100 berries was constant, and the probable alcohol was around 13% (v/v). A set of 250 grapes was collected haphazard per treatment and replicated (a set of 50 grape berries was frozen and stored at −20 °C until must volatile composition analysis was performed). Then, the remaining grapes were destemmed and crushed to obtain the musts, and the general parameters were analysed. Determination of general parameters in musts The grape must was analysed for enological parameters, such as ° Brix, probable alcohol, pH and total acidity, according to the official methods established by the OIV. 37 Glucose + fructose, glucose (and fructose indirectly, via subtraction of glucose + fructose −glucose), tartaric and malic acids, total phenols and nitrogen fractions were determined using a Miura One enzymatic equipment (TDI, Barcelona, Spain). The yeast assimilable nitrogen (YAN) was calculated as the sum of amino and ammonium nitrogen content. Because the treatments were performed in triplicate, the results of these parameters are shown as the average of three analyses (n=3). Analysis of volatile compounds in the musts by headspace solid-phase microextraction (HS-SPME)-gas chromatography (GC)-mass spectrometry (MS) Determination of volatile compounds in the musts was carried out by HS-SPME, and their subsequent analysis by GC-MS, according to the method described by Garde-Cerdán et al. 36 The SPME fibre used was divinylbenzene/carboxen/polydimethylsiloxane (50/30 μm) (Supelco, Bellenfonte, PA, USA). In a 20 mL vial (Supelco), 9 mL of sample, 2.5 g NaCl and 10 μL of internal standard (2-octanol; Sigma-Aldrich) were added. After adding a stir bar, the vial was closed and placed in the GC-MS (Agilent, Palo Alto, CA, USA). Sample conditioning was performed at 60 °C, for 15 min and with stirring. After this step, the fibre was automatically inserted into the headspace to extract the volatile compounds, for 105 min, with agitation. After the extraction process, the fibre was immediately introduced into the GC injection port at 250 °C and held for 15 min for desorption of the compounds of interest. The capillary column used for analyte separation is a SPB-20 (30 m ×0.25 mm inner diameter ×0.25 μmfilm thickness) (Supelco). Helium was used as the carrier gas at a flow rate of 1.2 mL min −1 . The chromatographic conditions used were initial temperature, 40 °C for 5 min, a temperature gradient of 2 °C min −1 ,uptoafinal temperature of 220 °C, which was maintained for 20 min (total time =115 min). The ionisation of the volatile compounds was performed at 70 eV. The detector worked at full scan mode (m/z35–300). Identification was carried out using the NIST library and compared with the chromatographic standards' mass spectra and retention time, when available, and with data found in the literature. A semiquantification was performed by relating the areas of each compound to the area and known concentration of the internal standard. Because the treatments were performed in triplicate, the results of volatile compounds are expressed as the mean concentration of the three replicates (n=3). Statistical analysis The statistical elaboration of the data was performed using SPSS, version 21.0 (IBM Corp. Armonk, NY, USA). General parameters and volatile compounds data were processed using analysis of variance (ANOVA) (P≤0.05). Differences between samples were compared using the Duncan test at a 95% probability level. Discriminant analysis was performed to classify the different samples according to their volatile composition. RESULTS AND DISCUSSION Non-toxic and biodegradable ACP nanoparticles provided slow release of MeJA or urea, as well as demonstrating a protective action against thermal degradation and ensuring a sustained supply of the biostimulants, resulting in a significant efficiency increase. Thus, ACP nanoparticles allow reduction of the biostimulant dosage by 10 or 15 times (MeJA or Ur, respectively), at the same time as maintaining the quality of the grapes. 21,29-31,33,35 In the present study, the effect of the foliar application of ACP nanoparticles functionalised with both molecules, MeJA and urea (ACP-MeJA+Ur), on the volatile composition of ‘Tempranillo’ grapes was evaluated for the first time. The effect of this novel nanoformulation was compared to the individual effect of each molecule, either free (MeJA, Ur) or loaded on the nanoparticle (ACP-MeJA, ACP-Ur), as well as the combinatorial effect of both free molecules (MeJA+Ur). Effect of the foliar treatments on the must general parameters The results of the general parameters in grapes of the control samples and those of the treatments (MeJA, ACP-MeJA, Ur, ACPUr, MeJA+Ur and ACP-MeJA+Ur) are shown in Table 1. The physico-chemical parameters, weight of 100 berries, °Brix, probable alcohol, Glu + Fru, Glu, Fru, pH, total acidity and tartaric acid, showed no changes between treated and control samples (Table 1); those results are in agreement with previous studies, where the application of conventional or nanoparticle-doped MeJA and/or Ur does not impact the majority of the general Biostimulants and nanotechnology as tools to change grape aroma www.soci.org J Sci Food Agric 2024 © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. wileyonlinelibrary.com/jsfa 3 10970010, 0, Downloaded from https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.13660 by Universidad De Granada, Wiley Online Library on [19/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License parameters of the must. 20,23,27,33,38,39 On the other hand, the foliar application of some treatments affected the rest of the musts enological parameters. The malic acid content increased by approximately 24.88% in the musts with the foliar application of MeJA +Ur, showing significant differences compared to control samples (Table 1). Garde-Cerdán et al. 40 reported, in the 2019 vintage, that the concentration of malic acid in MeJA-treated vines showed no difference compared to the control. However, in the 2020 vintage, the concentration of malic acid was slightly higher with the foliar application of MeJA and MeJA+Ur. From this, it can be inferred that, when conducting the study across different vintages, the concentration of malic acid in the must depends on various factors, such as climatic conditions and the degree of fruit ripeness. 27 The total phenols content decreased by 14.24%, 15.49%, 12.53% and 14.81%, with the application of MeJA, ACP-MeJA, Ur and ACP-MeJA+Ur, respectively, compared to the control samples. Additional research is needed to thoroughly investigate the impact of nano-treatments in total phenols content. Regarding nitrogen content, significant effects were only observed with the MeJA treatment (Table 1). Ammonium nitrogen increased (26.46%) with the application of MeJA compared to control must. Similar results were observed for amino nitrogen and YAN content because the application of MeJA and MeJA+Ur significantly increased these nitrogen fractions in the must compared to the control. Amino nitrogen increased by about 51.09% and 58.55%, respectively, whereas YAN increased by about 43.87% and 43.49%, respectively (Table 1). Similar results were reported in must from Tempranillo grapes treated with MeJA and MeJA+Ur in the 2019 vintage. 40 MeJA may affect the expression of genes linked to nitrogen metabolism in plants, potentially leading to increased synthesis of proteins and nitrogen compounds, thereby raising nitrogen concentration in grapevine tissues. 41,42 This could also explain the similar nitrogen fraction concentrations observed in Ur-treated grapevines compared to the control. Garde-Cerdán et al. 40 noted significant differences in YAN concentrations between the control grapes in 2019 and 2020, with higher levels in 2020. They attributed this variation to weather conditions, particularly the wetter conditions in 2020 promoting nutrient uptake and berry weight. They also emphasised the role of plant nutritional needs in nitrogen uptake. On the other hand, the results of the statistical analysis concerning the influence of the application method (conventional versus nanoparticles; individual versus combined) on the general parameters of the musts are shown in Table 2. Considering the effect of the form of application of the treatments (conventional versus nanoparticles), statistically significant differences were observed in some parameters with the application of MeJA versus ACPMeJA, obtaining higher contents of ammonium nitrogen, amino nitrogen and YAN, in the samples treated with MeJA compared to ACP-MeJA, whereas no significant effects were observed for any of the general parameters studied when Ur versus ACP-Ur treatments were applied (Table 2). Similarly, when applying MeJA+Ur, higher concentrations of malic acid, total phenols, amino nitrogen and YAN were obtained compared to the application of ACP-MeJA+Ur (Table 2). Finally, the combination of these biostimulants showed significant effects on some of the general parameters, i.e. total acidity, malic acid, total phenols, ammonium nitrogen, amimo nitrogen and YAN (Table 2), with their contents being intermediate or similar to that of some of the biostimulants applied individually. However, malic acid and total phenols increased significantly with the MeJA+Ur combination respect to the individual treatments (Table 2). Therefore, general Table 1. General parameters in grapes from control, methyl jasmonate (MeJA), methyl jasmonate on nanoparticles (ACP-MeJA), urea (Ur), urea on nanoparticles (ACP-Ur), methyl jasmonate + urea (MeJA +Ur) and methyl jasmonate + urea on nanoparticles (ACP-MeJA+Ur) foliar treatments. Control MeJA ACP-MeJA Ur ACP-Ur MeJA+Ur ACP-MeJA+Ur Weight of 100 berries (g) 221.65 ±8.11 a 230.00 ±18.18 a 216.56 ±35.38 a 237.75 ±36.80 a 235.34 ±15.92 a 213.31 ±19.99 a 224.72 ±5.72 a °Brix 21.53 ±0.75 a 20.80 ±0.87 a 21.27 ±1.69 a 21.87 ±2.28 a 21.40 ±0.52 a 21.27 ±1.76 a 20.57 ±0.55 a Probable alcohol (% v/v) 12.45 ±0.51 a 11.95 ±0.59 a 12.27 ±1.15 a 12.69 ±1.57 a 12.35 ±0.35 a 12.27 ±1.20 a 11.76 ±0.34 a Glu + Fru (g L −1 ) 205.57 ±10.30 a 199.08 ±9.42 a 215.32 ±21.32 a 213.05 ±26.55 a 214.55 ±4.71 a 203.99 ±22.61 a 206.36 ±8.64 a Glu (g L −1 ) 102.48 ±6.15 a 96.51 ±5.96 a 106.11 ±10.27 a 105.05 ±16.13 a 104.64 ±2.49 a 99.39 ±13.19 a 101.36 ±6.77 a Fru (g L −1 ) 103.08 ±4.16 a 102.57 ±3.46 a 109.22 ±11.06 a 108.00 ±10.52 a 109.92 ±3.25 a 104.60 ±9.57 a 105.00 ±1.98 a pH 3.67 ±0.09 a 3.70 ±0.06 a 3.73 ±0.21 a 3.73 ±0.11 a 3.73 ±0.07 a 3.87 ±0.05 a 3.86 ±0.13 a Total acidity (g L −1 ) a 4.89 ±0.17 a 4.90 ±0.35 a 4.53 ±0.09 a 4.89 ±0.51 a 4.93 ±0.17 a 4.96 ±0.45 a 4.88 ±0.14 a Tartaric acid (g L −1 ) 5.76 ±0.21 a 5.74 ±0.39 a 5.49 ±0.07 a 5.32 ±0.31 a 5.51 ±0.26 a 5.74 ±0.44 a 5.57 ±0.26 a Malic acid (g L −1 ) 2.17 ±0.05 a 2.09 ±0.28 a 2.22 ±0.23 a 2.28 ±0.11 a 2.38 ±0.23 ab 2.71 ±0.20 b 2.05 ±0.32 a Total phenols (mg L −1 ) 712.57 ±50.41 c 611.10 ±22.26 a 602.17 ±34.10 a 623.27 ±20.87 ab 697.03 ±51.83 bc 673.10 ±16.67 abc 607.07 ±13.16 a Ammonium nitrogen (mg N L −1 ) 68.01 ±4.62 a 85.97 ±7.63 b 63.70 ±9.53 a 65.52 ±7.44 a 56.42 ±5.19 a 72.80 ±12.87 ab 66.56 ±11.15 a Amino nitrogen (mg N L −1 ) 164.59 ±11.00 a 248.68 ±16.62 c 175.19 ±8.83 ab 153.44 ±13.45 a 153.28 ±11.65 a 260.96 ±19.24 c 190.74 ±13.25 b YAN (mg N L −1 ) 232.60 ±15.60 ab 334.65 ±23.35 c 238.89 ±12.62 ab 218.96 ±20.34 ab 209.70 ±16.79 a 333.76 ±31.44 c 257.30 ±23.00 b a As g L −1 tartaric acid. Glu: glucose; Fru: fructose; YAN: yeast assimilable nitrogen. All parameters are listed with their standard deviation (n=3). For each parameter, different lowercase letters indicate significant differences between the samples (P≤0.05). www.soci.org LL Torres-Díaz et al. wileyonlinelibrary.com/jsfa © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. J Sci Food Agric 2024 4 10970010, 0, Downloaded from https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.13660 by Universidad De Granada, Wiley Online Library on [19/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License parameters in grapes were slightly affected by the foliar treatments, with a greater influence on the nitrogen fractions and total phenols content in grapes. Influence of the foliar treatments on must volatile compounds: comparison with the control samples The results of the volatile compounds identified in the control musts and in the musts from the foliar treatments studied are presented Figs 1and 2and Tables 3and 4. In total, 38 volatile compounds were identified, belonging to the terpenoids, C 13 norisoprenoids, benzenoid compounds, alcohols, carbonyl compounds, esters and C6 compounds chemical families. Terpenoids Figure 1shows the terpenoids content in grapes. Terpenoids play a key role in grape varietal aroma because they contribute to the floral and citrus character. 4,5 Some of the most odiferous terpenoids are linalool, geraniol, nerol and ⊍-terpineol. The linalool content in the musts decreased with the foliar applications of ACP-Ur and ACP-MeJA+Ur (49.32% and 40.67%, respectively) (Fig. 1a). On the other hand, the ⊍-terpineol concentration in the musts increased by approximately 93.97% with Ur treatment (Fig. 1b). The γ-geraniol content in the musts was not affected by any of the treatments carried out in the vineyard (Fig. 1c). However, nerol synthesis decreased with foliar applications of Ur and MeJA+Ur (37.26% and 57.86%, respectively) (Fig. 1d). Geraniol biosynthesis was not favoured with ACP-MeJA +Ur application (Fig. 1e). In relation to neral, a decrease in its concentration was recorded in samples treated with Ur, MeJA+Ur and ACP-MeJA+Ur; this decrease was 46.83%, 62.19% and 38.9%, respectively (Fig. 1f). Finally, the concentration of geranyl acetone decreased in samples treated with ACP-MeJA, Ur and MeJA+Ur; in turn, the ACP-Ur treatment was the only one that significantly increased its content (44.56%) (Fig. 1g). Consequently, the total terpenoids content decreased by 36.33%, 46.25% and 18.83% with the foliar applications of ACP-MeJA, Ur and MeJA+Ur, respectively (Fig. 1h). Some research has reported the role of MeJA in activating terpenoids metabolism by increasing geranylgeranyl diphosphate synthase, 43 in contrast to the findings of the present study, where MeJA grapes did not show differences in terpenoids content compared to the control ones. However, the foliar application of MeJA on Sangiovese grapes led to an increase in the concentration of volatile compounds in both berries and wines, especially terpenoids, despite the naturally low levels of these volatile compounds in this grape variety. 7 Similarly, Gómez-Plaza et al. 43 reported that exogenous application of MeJA in ‘Monastrell’ berries stimulated terpenoids synthesis, presenting higher levels than in untreated grapes. Nevertheless, Garde-Cerdán et al. 4 did not show significant differences among untreated berries and grapes from vines foliar treated with proline, phenylalanine and urea in ‘Tempranillo’, results that agree with those of the present study when MeJA application was performed. C 13 norisoprenoids Figure 2presents the C 13 norisoprenoids identified in the must samples. C 13 norisoprenoids stem from the degradation of carotenoids. First, it was demonstrated that ⊎-cyclocitral content decreased (29.18%) in musts with Ur application (Fig. 2a). As for the TDN, ⊎-damascenone and ⊍-ionone, their concentration remained similar to the control samples (Fig. 2b–d). These findings align with those of Garde-Cerdán et al., 4 who found that the concentrations of C 13 norisoprenoids in ‘Tempranillo’grapes treated with phenylalanine, urea and proline showed no significant differences compared to the control. On the other hand, ⊎-ionone content in the grape musts decreased with ACP-MeJA, Ur and MeJA+Ur applications, by 30.25%, 35.80% and 51.62%, respectively (Fig. 2e). Finally, methyl jasmonate concentration decreased with all foliar treatments carried out in the vines (Fig. 2f). Therefore, the content of total C 13 norisoprenoids also decreased between 36.96% and 55.48% with foliar applications of ACP-Ur, MeJA+Ur and ACPMeJA+Ur (Fig. 2g). Table 2. One-factor ANOVA for enological parameters: conventional versus nano (MeJA/ACP-MeJA; Ur/ACP-Ur; MeJA+Ur/ACP-MeJA+Ur) and individual versus combined (MeJA/Ur/MeJA+Ur; ACP-MeJA/ACP-Ur/ACP-MeJA+Ur). MeJA/ ACP-MeJA Ur/ACP-Ur MeJA+Ur/ACPMeJA+Ur MeJA/Ur/MeJA+Ur ACP-MeJA/ACP-Ur/ACPMeJA+Ur FPFPFPFPFP Weight of 100 berries (g) 0.343 0.590 0.011 0.922 0.903 0.396 0.674 0.545 0.519 0.619 °Brix 0.181 0.692 0.119 0.747 0.434 0.546 0.284 0.762 0.528 0.615 Probable alcohol (% v/v) 0.187 0.687 0.129 0.738 0.489 0.523 0.291 0.757 0.585 0.586 Glu + Fru (g L −1 ) 1.457 0.294 0.009 0.928 0.029 0.873 0.346 0.721 0.403 0.685 Glu (g L −1 ) 1.963 0.234 0.002 0.967 0.053 0.829 0.362 0.711 0.338 0.726 Fru (g L −1 ) 0.985 0.377 0.091 0.778 0.005 0.946 0.315 0.741 0.465 0.649 pH 0.045 0.842 0.000 1.000 5.741 0.075 4.235 0.071 0.114 0.894 Total acidity (g L −1 ) 3.237 0.146 0.015 0.909 0.103 0.764 0.025 0.976 7.664 0.022 a/b/b Tartaric acid (g L) 1.206 0.334 0.651 0.465 0.313 0.606 1.169 0.373 0.127 0.883 Malic acid (g L −1 ) 0.407 0.558 0.488 0.523 9.147 0.039 7.044 0.027 a/a/b 1.178 0.370 Total phenols (mg L −1 ) 0.030 0.872 5.229 0.084 29.013 0.006 8.036 0.020 a/a/b 2.464 0.166 Ammonium nitrogen (mg N L −1 ) 9.981 0.034 3.017 0.157 0.403 0.560 3.463 0.050 b/a/ab 1.016 0.417 Amino nitrogen (mg N L −1 ) 45.736 0.002 0.000 0.989 27.092 0.006 37.673 0.000 b/a/b 8.187 0.019 ab/a/b YAN (mg N L −1 ) 39.049 0.003 0.369 0.576 11.561 0.027 20.465 0.002 b/a/b 5.344 0.046 ab/a/b For the factor individual versus combined, different lowercase letters indicate significant differences among treatments, for each parameter (P≤0.05). Biostimulants and nanotechnology as tools to change grape aroma www.soci.org J Sci Food Agric 2024 © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. wileyonlinelibrary.com/jsfa 5 10970010, 0, Downloaded from https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.13660 by Universidad De Granada, Wiley Online Library on [19/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License After assessing the effect of MeJA on ‘Tempranillo’grapes during three vintages, Garde-Cerdán et al. 36 observed that the formation of volatile compounds depends on several factors, such as variety, viticultural practices, climatic conditions, soil characteristics and degree of fruit ripening. Within this family, the most important compounds are ⊎-damascenone and ⊎-ionone, as they are the most important contributors to odour and flavour, providing aromas of roses and violets. 4,36,43 Similar to terpenoids, this family has low perception thresholds, thus enhancing the aroma of many grape varieties. 44 Benzenoid compounds Two benzenoid compounds were identified: 2-phenylethanal and 2-phenylethanol (Table 3). The ACP-MeJA, Ur, MeJA+Ur and ACPMeJA+Ur treatments stimulated the synthesis of 2-phenylethanal in the musts, obtaining a higher content compared to the control samples, at 136.74%, 55.24%, 172.02% and 66.05%, respectively. Figure 1. Terpenoids concentration (μgL −1 ) (a, linalool; b, ⊍-terpineol; c, γ-geraniol; d, nerol; e, geraniol, f, neral; g, geranyl acetone; h, total terpenoids) in grapes from control, methyl jasmonate (MeJA), methyl jasmonate on nanoparticles (ACP-MeJA), urea (Ur), urea on nanoparticles (ACP-Ur), methyl jasmonate + urea (MeJA+Ur) and methyl jasmonate + urea on nanoparticles (ACP-MeJA+Ur) foliar treatments. All parameters are listed with the SD (n=3). Different lowercase letters indicate significant differences between samples (P≤0.05) for each season and compound. www.soci.org LL Torres-Díaz et al. wileyonlinelibrary.com/jsfa © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. J Sci Food Agric 2024 6 10970010, 0, Downloaded from https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.13660 by Universidad De Granada, Wiley Online Library on [19/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License On the other hand, 2-phenylethanol content decreased (61.46%) in the samples from Ur foliar applications. Garde-Cerdán et al. 36 reported that benzenoid compounds and their total content in ‘Tempranillo’grapes were not affected by foliar application of MeJA, in agree with the results of the present study, because the only treatment that affected the content of total benzenoid compounds was the foliar application of Ur, reducing its content in the musts (Table 3). Alcohols Concerning alcohols, most treatments did not affect heptanol concentration, except for the foliar application of Ur and MeJA +Ur, which resulted in a higher concentration compared to the control sample. Specifically, increases of 114.29% and 214.29%, respectively, were observed (Table 3). Similarly, the concentration of 1-octen-3-ol increased by 75.74% in the samples treated with ACP-Ur, whereas ACP-MeJA and MeJA+Ur decreased their Figure 2. C 13 norisoprenoids concentration (μgL −1 ) (a, ⊎-cyclocitral; b, TDN; c, ⊎-damascenone; d, ⊍-ionone; e, ⊎-ionone; f, methyl jasmonate; g, total C 13 norisoprenoids) in grapes from control, methyl jasmonate (MeJA), methyl jasmonate on nanoparticles (ACP-MeJA), urea (Ur), urea on nanoparticles (ACP-Ur), methyl jasmonate + urea (MeJA+Ur) and methyl jasmonate + urea on nanoparticles (ACP-MeJA+Ur) foliar treatments. All parameters are listed with the SD (n=3). Different lowercase letters indicate significant differences between samples (P≤0.05) for each season and compound. TDN, 1,1,6-trimethyl-1,2-dihydronaphthalene. Biostimulants and nanotechnology as tools to change grape aroma www.soci.org J Sci Food Agric 2024 © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. wileyonlinelibrary.com/jsfa 7 10970010, 0, Downloaded from https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.13660 by Universidad De Granada, Wiley Online Library on [19/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License Table 3. Concentration (μgL −1 ) of benzenoid compounds, alcohols, carbonyl compounds, esters, and C6 compounds in grapes from control, methyl jasmonate (MeJA), methyl jasmonate on nanoparticles (ACP-MeJA), urea (Ur), urea on nanoparticles (ACP-Ur), methyl jasmonate + urea (MeJA+Ur) and methyl jasmonate + urea on nanoparticles (ACP-MeJA+Ur) foliar treatments. Control MeJA ACP-MeJA Ur ACP-Ur MeJA+Ur ACP-MeJA+Ur Benzenoid compounds 2-Phenylethanal 1.09 ±0.01 a 1.45 ±0.29 ab 2.59 ±0.14 d 1.70 ±0.17 bc 1.12 ±0.1 a 2.98 ±0.12 e 1.82 ±0.25 c 2-Phenylethanol 6.37 ±0.15 b 6.07 ±1.49 b 4.41 ±2.02 ab 2.45 ±0.10 a 5.37 ±1.03 b 3.76 ±0.11 ab 5.14 ±0.25 b Total benzenoid compounds 7.46 ±0.10 b 7.52 ±1.67 b 7.01 ±2.11 b 4.16 ±0.19 a 6.49 ±0.64 b 6.74 ±0.16 b 6.96 ±0.51 b Alcohols Heptanol 0.07 ±0.01 a 0.11 ±0.01 ab 0.13 ±0.05 ab 0.15 ±0.04 b 0.08 ±0.00 a 0.22 ±0.03 c 0.12 ±0.01 ab 1-Octen-3-ol 1.36 ±0.25 c 1.22 ±0.08 bc 0.68 ±0.19 a 1.01 ±0.14 abc 2.39 ±0.52 d 0.8 ±0.08 ab 1.36 ±0.15 c 2-Ethyl-1-hexanol 2.3 ±0.09 b 2.18 ±0.23 b 1.74 ±0.46 ab 1.78 ±0.48 ab 1.8 ±0.1 ab 1.46 ±0.03 a 1.85 ±0.33 ab 1-Nonanol 0.49 ±0.09 a 0.59 ±0.1 a 1.21 ±0.35 b 0.51 ±0.14 a 0.55 ±0.07 a 1.46 ±0.09 b 0.8 ±0.14 a 1-Decanol 0.1 ±0.01 ab 0.1 ±0.02 b 0.11 ±0.03 b 0.1 ±0.04 ab 0.05 ±0.01 a 0.1 ±0.00 ab 0.05 ±0.01 a 1-Dodecanol 0.17 ±0.01 b 0.13 ±0.00 ab 0.11 ±0.04 ab 0.08 ±0.01 a 0.15 ±0.01 ab 0.12 ±0.00 ab 0.28 ±0.06 c Total alcohols 4.49 ±0.17 a 4.34 ±0.17 ab 3.98 ±0.75 ab 3.64 ±0.58 a 5.03 ±0.45 b 4.16 ±0.01 ab 4.45 ±0.28 ab Carbonyl compounds (E)-2-Heptenal 0.21 ±0.05 b 0.08 ±0.01 a 0.07 ±0.01 a 0.09 ±0.00 a 0.36 ±0.12 c 0.1 ±0.01 a 0.16 ±0.00 ab Nonanal 3.51 ±0.37 bc 2.68 ±0.26 ab 2.18 ±0.79 a 1.87 ±0.28 a 5.56 ±1.04 d 2.88 ±0.52 ab 4.66 ±0.44 cd (E)-2-Nonenal 0.48 ±0.13 bc 0.61 ±0.11 cd 0.29 ±0.04 a 0.27 ±0.06 a 0.69 ±0.08 d 0.41 ±0.09 ab 0.53 ±0.13 bcd Decanal 0.41 ±0.07 de 0.33 ±0.05 cd 0.19 ±0.06 ab 0.18 ±0.06 a 0.29 ±0.03 bc 0.44 ±0.05 e 0.23 ±0.01 abc γ-Decalactone 0.11 ±0.02 a 0.15 ±0.02 a 0.1 ±0.02 a 0.34 ±0.08 c 0.14 ±0.05 a 0.25 ±0.00 b 0.11 ±0.03 a (E,E)-2,4-Hexadienal 1.29 ±0.27 c 0.78 ±0.14 b 0.46 ±0.1 a 0.38 ±0.04 a 0.82 ±0.13 b 0.28 ±0.01 a 0.35 ±0.01 a (E,E)-2,4-Heptadienal 1.19 ±0.09 d 0.85 ±0.12 c 0.48 ±0.24 ab 0.21 ±0.00 a 0.69 ±0.21 bc 0.28 ±0.03 a 0.37 ±0.06 a 6-Methyl-3,5-heptadien-2-one 0.04 ±0.00 de 0.03 ±0.00 cd 0.02 ±0.00 b 0.03 ±0.00 bc 0.04 ±0.01 e 0.00 ±0.00 a 0.03 ±0.00 cd (E,E)-2,4-Nonadienal 0.38 ±0.04 c 0.36 ±0.03 c 0.2 ±0.02 a 0.25 ±0.02 ab 0.47 ±0.08 d 0.23 ±0.03 a 0.32 ±0.02 bc (E,E)-2,4-Decadienal 0.08 ±0.01 a 0.06 ±0.01 a 0.04 ±0.01 a 0.04 ±0.01 a 0.46 ±0.08 b 0.02 ±0.00 a 0.05 ±0.01 a Total carbonyl compounds 7.72 ±0.66 d 5.93 ±0.57 bc 4.03 ±1.138 a 3.64 ±0.24 a 9.52 ±1.65 e 4.90 ±0.59 ab 6.80 ±0.56 cd Esters Hexyl acetate 0.04 ±0.00 a 0.03 ±0.00 a 0.04 ±0.01 a 0.03 ±0.01 a 0.05 ±0.03 a 0.22 ±0.01 b 0.02 ±0.00 a Ethyl 2-hexenoate 0.03 ±0.00 ab 0.04 ±0.00 bc 0.02 ±0.00 a 0.03 ±0.01 ab 0.04 ±0.01 bc 0.08 ±0.00 d 0.05 ±0.01 c Total esters 0.07 ±0.00 ab 0.07 ±0.00 ab 0.06 ±0.01 a 0.06 ±0.01 a 0.09 ±0.02 b 0.3 ±0.01 c 0.07 ±0.01 ab C6 compounds 1-Hexanol 15.58 ±2.4 ab 19.02 ±0.28 b 13.95 ±1.87 ab 40.42 ±2.32 d 14.91 ±1.41 ab 25.9 ±5.58 c 11.78 ±0.67 a (Z)-3-Hexen-1-ol 0.44 ±0.08 b 0.95 ±0.17 c 1.54 ±0.06 d 0.47 ±0.02 b 0.36 ±0.01 ab 0.21 ±0.02 a 0.21 ±0.03 a (E)-2-Hexen-1-ol 3.49 ±0.53 ab 3.027 ±0.21 ab 1.57 ±0.02 a 5.99 ±2.15 c 1.83 ±0.12 a 4.35 ±0.32 bc 1.91 ±0.21 a Hexanal 47.15 ±5.94 d 45.21 ±3.74 cd 22.69 ±5.68 a 28.32 ±5.09 ab 36.16 ±2.38 bc 41.02 ±5.97 cd 30.66 ±4.18 ab (E)-2-Hexenal 19.91 ±1.79 cd 21.16 ±2.31 d 9.89 ±3.19 a 16.09 ±0.89 b 12.31 ±1.41 a 17.24 ±0.74 bc 10.85 ±1.86 a Total C6 compounds 86.57 ±9.78 c 89.36 ±5.86 c 49.64 ±7.06 a 91.27 ±4.93 c 65.57 ±5.32 b 88.74 ±6.96 c 55.41 ±6.44 ab All parameters are shown with their standard deviation (n=3). For each compound, different lowercase letters indicate significant differences between treatments (P≤0.05). www.soci.org LL Torres-Díaz et al. wileyonlinelibrary.com/jsfa © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. J Sci Food Agric 2024 8 10970010, 0, Downloaded from https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.13660 by Universidad De Granada, Wiley Online Library on [19/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License Table 4. One-factor ANOVA for volatile compounds: conventional versus nano (MeJA/ACP-MeJA; Ur/ACP-Ur; MeJA+Ur/ACP-MeJA+Ur) and individual versus combined (MeJA/Ur/MeJA+Ur; ACP-MeJA/ ACP-Ur/ACP-MeJA+Ur). MeJA/ACP-MeJA Ur/ACP-Ur MeJA+Ur/ACP-MeJA+Ur MeJA/Ur/MeJA+Ur ACP-MeJA/ACP-Ur/ACP-MeJA+Ur FP FP F P F P F P Terpenoids Linalool 2.64 0.18 0.012 0.92 11.52 0.027 2.46 0.17 0.07 0.94 ⊍-Terpineol 0.67 0.47 30.01 0.01 25.55 0.015 5.39 0.06 1.97 0.25 γ-Geraniol 0.45 0.57 7.497 0.05 10.14 0.033 6.54 0.04 ab/b/a 0.95 0.45 Nerol 1.77 0.31 14.36 0.03 72.36 0.003 11.64 0.04 b/a/a 4.22 0.08 Geraniol 5.89 0.09 0.28 0.64 10.83 0.046 2.05 0.22 0.47 0.66 Neral 0.86 0.40 48.69 0.01 19.21 0.012 21.24 0.00 b/a/a 1.10 0.40 Geranyl acetone 30.88 0.03 603.50 0.00 46.59 0.002 95.23 0.00 c/a/b 82.62 0.00 a/c/b Total terpenoids 16.95 0.01 71.99 0.00 1.68 0.264 19.55 0.00 c/a/b 23.34 0.00 a/c/b C 13 norisoprenoids ⊎-Cyclocitral 2.23 0.21 23.62 0.01 70.19 0.001 6.02 0.04 b/a/ab 5.06 0.05 a/b/b TDN 0.89 0.44 3615.12 0.00 0.00 0.982 10.40 0.05 b/b/a 4.09 0.11 ⊎-Damascenone 1.54 0.34 127.40 0.01 0.68 0.497 40.62 0.01 b/b/a 3.39 0.17 ⊍-Ionone 1.17 0.34 0.00 0.99 6.81 0.080 2.13 0.21 0.04 0.96 ⊎-Ionone 3.31 0.17 26.59 0.01 21.42 0.010 11.04 0.01 b/a/a 6.24 0.04 a/b/ab Methyl jasmonate 14.45 0.03 31.22 0.01 ––59.71 0.00 c/b/a 56.52 0.00 b/a/a Total C 13 norisoprenoids 1.65 0.27 18.82 0.01 72.06 0.001 56.09 0.00 b/b/a 5.15 0.05 b/a/a Benzenoid compounds 2-Phenylethanal 1.308 0.32 15.97 0.06 8.41 0.063 7.504 0.04 b/a/ab 0.33 0.73 2-Phenylethanol 25.008 0.04 24.33 0.02 35.15 0.027 31.51 0.01 a/a/b 50.98 0.00 c/a/b Total benzenoid compounds 0.109 0.76 35.83 0.00 0.50 0.518 9.79 0.01 b/a/b 0.14 0.87 Alcohols Heptanol 0.395 0.57 7.41 0.11 13.53 0.067 6.12 0.09 1.66 0.30 1-Octen-3-ol 20.88 0.02 22.38 0.02 22.05 0.018 9.26 0.02 b/ab/a 17.02 0.01 a/b/a 2-Ethyl-1-hexanol 1.51 0.31 0.01 0.94 2.45 0.216 2.08 0.24 0.08 0.92 1-Nonanol 5.55 0.14 0.16 0.72 43.63 0.007 62.32 0.00 a/a/b 6.75 0.05 b/a/ab 1-Decanol 0.00 0.97 2.12 0.24 30.47 0.012 0.04 0.96 6.23 0.04 b/a/a 1-Dodecanol 0.55 0.54 62.68 0.00 10.58 0.047 34.69 0.01 b/a/b 10.03 0.02 a/a/b Total alcohols 0.67 0.46 10.76 0.03 3.22 0.147 3.34 0.11 2.89 0.13 Carbonyl compounds (E)-2-Heptenal 1.63 0.33 18.81 0.02 68.58 0.00 3.56 0.11 9.61 0.05 a/b/ab Nonanal 0.69 0.47 21.96 0.02 20.38 0.01 3.85 0.12 14.48 0.00 a/b/b (E)-2-Nonenal 22.91 0.01 51.46 0.00 1.72 0.26 11.40 0.01 b/a/a 14.99 0.00 a/b/b Decanal 8.95 0.04 9.26 0.04 27.28 0.04 13.64 0.01 b/a/b 4.62 0.07 γ-Decalactone 7.23 0.07 13.24 0.04 31.21 0.01 12.89 0.02 a/b/ab 0.68 0.55 (E,E)-2,4-Hexadienal 7.73 0.07 32.38 0.01 46.77 0.02 22.41 0.00 b/a/a 15.06 0.01 a/b/a (E,E)-2,4-Heptadienal 5.59 0.09 9.50 0.05 21.78 0.04 42.90 0.00 b/a/a 1.76 0.28 6-Methyl-3,5-heptadien-2-one 19.31 0.02 8.43 0.06 121.52 0.00 86.39 0.00 b/b/a 7.61 0.04 a/b/ab (E,E)-2,4-nonadienal 45.73 0.02 23.25 0.01 15.10 0.03 16.381 0.01 b/a/a 23.81 0.00 a/c/b Biostimulants and nanotechnology as tools to change grape aroma www.soci.org J Sci Food Agric 2024 © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. wileyonlinelibrary.com/jsfa 9 10970010, 0, Downloaded from https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa.13660 by Universidad De Granada, Wiley Online Library on [19/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License