Impact of Zulla cover crop in vineyard on the musts volatile profile of Vitis vinifera L. cv Syrah

Food Research International 160 (2022) 111694 Available online 14 July 2022 0963-9969/© 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/). Impact of Zulla cover crop in vineyard on the musts volatile profile of Vitis vinifera L. cv Syrah E. Valero a , F. Arranz b , B.J. Moy´ a b , S. Cruz c , B. Puertas c , M.L. Morales b , * a ´ Area de Nutrici´ on y Bromatología, Dpto. Biología Molecular e Ingeniería Bioquímica, Univ. Pablo de Olavide, Sevilla, Espa˜ na b ´ Area de Nutrici´ on y Bromatología, Dpto. Nutrici´ on y Bromatología, Toxicología y Medicina Legal, Fac. Farmacia, Univ. Sevilla, Sevilla, Espa˜ na c Instituto de Investigaci´ on y Formaci´ on Agraria y Pesquera (IFAPA), Rancho de la Merced, 11471 Jerez de la Frontera, Espa˜ na ARTICLE INFO Keywords: Cover crop Soil tillage Organic cultivation Grape must Volatile compounds Hedysarum coronarium L. Warm climate ABSTRACT Grape aromatic characteristics are very important for producing quality wines. There have been very few studies on concentrations of volatile compounds in grape berries from vines with cover crops. For this reason, the aim of this work was to evaluate the influence of “Zulla” cover crop on the volatile profiles of organically grown Syrah variety grapes. For this purpose, volatile profiles of grapes obtained from vines with three different amounts of cover crop (one line, two lines, and four lines) and without cover crop, over three harvests (2019, 2020, and 2021) were determined. Moreover, a comparative study of conventional and organic crops, both submitted to soil tillage, was performed. The grape samples came from a warm climate zone. Must volatile compounds were determined by sequential sorptive extraction with Twisters by immersion (SBSE) and headspace (HSSE), followed by GC–MS analysis. A total of 160 compounds were determined and most of them were influenced by the presence of cover crop. However, the results showed an important influence of the harvest year over agronomic practices. Therefore, organic cultivation using Zulla cover crop seems to be a suitable tool for the implementation of friendly ecosystem management in a warm climate Syrah vineyard. 1. Introduction There is important world interest in increasing organic farming to guarantee environmental sustainability and biodiversity, among other positive effects. In 2019, Spain was the country with the largest number of hectares of organic vineyards worldwide (27% of the world’s organic vineyard area) (OIV, 2021). In this kind of cultivation, herbicides cannot be used to prevent the growth of vegetation between rows of vines. Thus, tilling the soil is the most widespread agronomic practice used to keep the ground free from vegetation. However, this soil management strategy favours soil erosion and alters its microbiota (Abad, Marín, Santesteban, Cibriain, & Sagü´ es, 2020). As an alternative, the use of cover cropping is proposed in organic vineyards, which implies benefits for soil quality, but it could also reduce the availability of nutrients and water for the vine (Bouzas-Cid, Trigo-C´ ordoba, Orriols, Falqu´ e, & Mir´ as- Avalos, 2018), influencing the canopy vigour and consequently the must quality. The kinds of plants most used as cover crops in vineyards are grasses and legumes (Abad, de Mendoza, Marín, Orcaray, & Gonzaga Santesteban, 2021). The former provides organic material, and the latter increase the soil nitrogen. Wine organoleptic characteristics such as colour, aroma, and taste drive their purchase by the consumer. Wine aroma is constituted by a wide variety of volatile compounds with different origins, directly deriving from grape (i.e., varietal or primary aromas), or formed during fermentation and post-fermentation steps (Antalick et al., 2015; Morales, Fierro-Risco, Ríos-Reina, Ubeda, & Paneque, 2019; Rib´ ereau- Gayon, Glories, Maujean, & Dubourdieu, 2006). With respect to the varietal aroma, in addition to depending on the grape variety, this could be affected by many other factors, such as sunlight radiation, water deficit, temperature, or soil management, among others (Alem, Rigou, Schneider, Ojeda, & Torregrosa, 2019; Coletta et al., 2021). Among red grape varieties, Syrah is one grape variety cultivated in many countries (31) and, in 2015, its vineyard area was 190,000 ha. In Spain, the percentage of cultivation is still low, occupying 2.1% of the total of vineyard ha (OIV, 2017). Its cultivation is easy, despite the fact that it requires a lot of hours of sunshine and medium–high temperatures. It is a type of grape that resists most of the diseases that affect other varieties. Syrah is used to produce monovarietal as well as blended wines. They are very pleasant, balanced and structured wines, * Corresponding author. E-mail address: [email protected] (M.L. Morales). Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres https://doi.org/10.1016/j.foodres.2022.111694 Received 31 March 2022; Received in revised form 6 July 2022; Accepted 12 July 2022 Food Research International 160 (2022) 111694 2 characterised by an intense red colour and fruity aromas (predominantly forest fruits) (Pe˜ nín & Diez, 1997). There have been very few studies of the effect of vineyard cover crops on the volatile profile of grapes and controversial results have been obtained. On one hand, Xi, Tao, Zhang, and Li (2011) studied the influence of permanent green cover crops on Cabernet Sauvignon vines from northwest China. They concluded that wines from cover crops had higher contents of volatile compounds, thus, this agronomic practice could enhance the wine content of aroma compounds. On the other hand, Coletta et al. (2021) researched the effect of cover crops on the Negroamaro grape variety from southern Italy and they observed that soil tillage treatment favoured the concentrations of free volatile versus cover crop treatment. More recently, Bouzas-Cid et al. (2018) evaluated permanent cover crops on the volatile profile of wines from the Mencía variety grape grown in northwest Spain. These researchers concluded that this practice slightly influenced the concentrations of volatiles in the studied wines, therefore, the wine aroma might be modulated using cover crops in humid climates. Then, the use of cover crops may produce different effects, depending on grape variety, climate, the kind of cover crop, and its management. Consequently, its use should be evaluated for each grape variety, climate, and agronomic condition. The use of cover crops may also contribute to preserving plant biodiversity, therefore, the use as cover crop of plants from wild autochthonous flora should be encouraged, since these also have the advantage of being adapted to the local climate. Different assays of cover crops with Syrah vines have been performed, using Medicago truncatula, Medicago rigidula, Medicago polymorpha and spontaneous crops (Kazakou et al., 2016), Medicago truncatula, M. rigidula, and M. polymorpha (Guilpart, Roux, Gary, & Metay, 2017), Festuca rubra (Delpuech & Metay, 2018), Bromus hordeaceus and Secale cereal (Linares Torres, De La Fuente Lloreda, Junquera Gonzalez, Lissarrague Garcia-Gutierrez, & Baeza Trujillo, 2018). In these works, several parameters have been studied, such as grape and vine yield, vine leaf water potential, assimilable nitrogen in grapes, or disease susceptibility. However, to our knowledge, the extent to which a cover crop influences the volatile composition of Syrah grape is yet to be studied. The aim of this work was to study, for the first time, the effect of organic cultivation and different amounts of Zulla cover crop on the free volatile compounds of Syrah grapes grown in warm climates. Moreover, a comparative study of conventional and organic crops, both submitted to soil tillage, was performed. Zulla (Hedysarum coronarium L.) is a wild legume originated from the Mediterranean basin (Tava et al., 2021). This plant grows spontaneously in the study area, therefore, its use will contribute to biodiversity maintenance. To our knowledge, this wild plant has not been used as a vineyard cover crop. Although major studies about the effects of agronomic factors have been performed by analysing the wines, in our work the volatile composition was directly determined in must samples, since the alcoholic fermentation factors have a significant influence on the volatile profile of the resulting wines, which makes it difficult to have a clear idea of which changes are due to agronomic factors. 2. Materials and methods 2.1. Samples This study was performed during three consecutive vintages, 2019, 2020, and 2021. in two vineyards (conventional and organic), with Vitis vinifera L. cv Syrah grapevine. Vineyards were located in the IFAPA Centre “Rancho de La Merced”, in the Jerez winegrowing region, Spain (36:45:29 N, 06:00:58 W, 35 m altitude), in an area with limestone soil composed of 19% sand, 38.5% clay, and 42.5% silt. The distance between the two vineyards was 2 Km and both are included in region V according to climatic classification of viticultural regions by Amerine and Winkler (1944). Climatological data was taken from the vineyard weather station, and shown in Fig. 1S. (A and B). In both the conventional and organic vineyards, the rootstock of vines was 140 Ru., and the vines were trained on the trellis system of three wire and winter pruning was double cordon, with 2 arms, 3 spurs per arm and 2 buds per spur. That is, a load of 12 buds per vine. The grapes were harvested manually. A vineyard with bare soil by tillage was used as a control. No irrigation was performed in the vineyards. The conventional vineyard was treated with agricultural chemicals, such as gliphosate 25%, difluphenican 6,25% and metribuzin 25% at the rate of 4 L/Ha as herbicide, and different treatments were applied, such as insecticide, nematicide and fungicide, at four different times and doses, between March and June. All products were applied either around or directly onto the grape vines. The organic vineyard was treated only with micronised sulfur (98.5% sulfur, DP. Afepasa) at the rate of 30 kg/Ha, and copper oxychloride 70% (Oxirame 70, Naturdai) as fungicide. Zulla (Hedysarum coronarium L.) cover crops were planted (20 Kg/ Ha) in lanes 4, 5, 10, 11, 14, 15, 16, and 17 (Fig. 2S, supplementary material), in October 2018 and were maintained until March 2019. At this time, it was cleared and a week later the lanes were tilled to avoid the cover ground competing with the vineyard. In the second and third years (2019–20 and 2020–21), the cover crop was allowed to grow spontaneously, with no new planting of Zulla, and the same process of clearing and soil tillage was carried out. In order to evaluate the volatile composition of musts, three sampling campaigns were performed. Bunches were always collected from the same plant at a similar maturation stage (approx. 24 ◦Brix). With the present experimental design, 15 grape samples were collected every year, 12 grape samples in the organic vineyard (SE), for every cover crop density (3 samples for every different density) and 3 grape samples in the conventional vineyard (SC). The different cover crop densities evaluated were cover crop on one side and tillage on the other side of the row (LZ), cover crop on both sides of the row (ZZ), cover crop on two rows on both sides of the sampled row (4Z) and tillage on both sides of the vine row as a control (LL). Approximately 2 kg of grapes, stems included, were harvested in aseptic conditions from each sampling point and placed directly into sterile bags, which were transported to the laboratory in portable refrigerators with plastic ice blocks. At the laboratory, grapes were squeezed by hand in the plastic bags, opened and about 50 mL of juice was poured into a glass vial for further volatile compounds analyses. 2.2. Determination of volatile compounds in musts by SBSE-HSSE-GC-MS The musts’ volatile fraction was extracted by a sequential sorptive extraction with polydimethylsiloxane Twisters®. Two Twisters® were used for each sample. The two steps of the sequential extraction procedure were, first, an extraction in immersion (SBSE), followed by an extraction in headspace (HSSE) (Ubeda, Callej´ on, Troncoso, Pe˜ na-Neira, & Morales, 2016). 7.5 mL of must were placed into a 20 mL vial, plus 10 µL of the internal standard (4-methyl-2-pentanol, 1044 mg/L) and 2.25 gr of NaCl. For the sequential extraction procedure, a Twister® was immersed in the sample using a Twicester® device for 1 h, at room temperature, while the sample was stirred with a conventional magnetic stir bar at 200 rpm. Subsequently, the twister was removed with tweezers, rinsed with Milli-Q water, dried with lint-free tissue paper and reserved in a tightly closed 2 mL vial. Then, another twister was placed in an open glass insert inside the vial and the sample was heated in a water bath at 62 ◦C for 1 h. The twister was removed from the vial, and we proceeded in the same way as mentioned above. Both twisters were then introduced into the same desorption tube and simultaneously desorbed. The analytical equipment, desorption conditions, and GC–MS used are detailed in Ubeda et al. (2016). Compounds were identified using mass spectra matching the NIST/ EPA/NIH Mass Spectral Library (NIST 17) and the linear retention index (LRI) of authentic reference standards. LRIs were calculated by injecting E. Valero et al. Food Research International 160 (2022) 111694 3 n-alkanes mixture (C10–C40) under conditions identical to those of the samples. Subsequently, we considered the identification of a compound confirmed when the mass spectrum and LRI values matched those of the standards. The identification of a compound was considered tentatively (TI) when its mass spectrum matched that of the NIST mass spectral library and its LRI value that of the literature. For the remaining compounds, of which only their mass spectrum matched that of the NIST library, their identification cannot be confirmed, furthermore, among these we call unknown compounds (n.i.) the compounds that had low values of probability of right identification in the search results in the NIST library. 2.3. Statistical analyses The values of relative peak area of the diverse VOCs found in each agronomic treatment were subjected to analysis of variance (ANOVA) (Fisher’s LSD post hoc test) using INFOSTAT software (FCA, Universidad Nacional de C´ ordoba, Argentina). The possible existence of correlations between an abundance of Zulla and volatile compounds was also studied by regression analysis. The multivariant statistical analysis performed was principal component analysis (PCA). These last two analyses were performed using Statsoft Statistical, version 7.0 (Statsoft, Tulsa, OK). Heatmap visualisation of cluster analysis was performed using the MetaboAnalyst 4.0 (web interface) (Chong & Xia, 2018). 3. Results and discussion A total of 160 volatile compounds were detected by a sequential extraction procedure SBSE-HSSE followed by TD-GC-MS analysis in free fractions from Syrah musts. The total number of compounds detected in each harvest was different, ranging from 123 in the 2020 harvest and 156 in the 2019 harvest. Eighty-two of them were positively identified by mass spectrum according to the mass spectral database and standard LRI and 39 tentatively identified (TI) by mass spectrum and LRI according to data found in the literature. Results were expressed as relative peak area values with respect to IS and are shown in Table 1, classified according to their functional groups. Alcohols, aldehydes, and ketones were the main volatile compounds identified in the three harvests. The highest total content of volatile compounds was observed in musts from 2019 for most of the different cultivation conditions studied. There were several compounds detected only in one harvest, we can highlight veratrol in 2019, an aldehyde tentatively identified as safranal in 2020, and heptanal in the 2021 harvest, among others. Veratrol (1,2- dimethoxybenzene) is a volatile compound related to insect attraction (D¨ otterl & Jurgens, 2005), it was detected in female inflorescences of wild grapevine (Zito, Scrima, Sajeva, Carimi, & D¨ otterl, 2016). Conversely, rotundone, a sesquiterpene compound characteristic of the Syrah grape variety from cool climates (Wood et al., 2008), was not detected as expected. In order to discuss the results of this work, first of all, we are going to contrast the musts’ volatile composition from conventional and organic cultivation, both subjected to soil tillage, and subsequently, the organic musts’ volatile composition from vines cultivated with different proportions of Zulla covert crop. 3.1. Conventional crop versus organic crop The volatile composition of musts from the Syrah grape variety obtained from conventional and organic cultivation during three harvests was compared. Considering jointly the results of the three harvests, we observed similar trends in the total content of aldehydes, nitrogen compounds, and C 13 -norisoprenoinds, which were higher in organic than in conventional cultivation. The differences were significant in the case of total content of nitrogen compounds and C 13 -norisoprenoinds. Among compounds detected in the three harvests, 19 of them presented higher contents in musts from organic than in conventional cultivation. Besides, the differences were significant for 1-nonanol, 2-heptenal, trans, cis-2,4-heptadienal, trans-2-nonenal, 2,3-octanedione, 6-methyl-5- hepten-2-one, 4-methyl-5H-furan-2-one, γ-decalactone, β-damascenone, cis-linalool oxide, hotrienol, epoxylinalol, and the unknown compound n.i. (m/z 70-55-43). These compounds provide herbaceous, floral, and fruity aromas. Conversely only three compounds were more abundant in musts from conventional cultivation than in organic musts, namely benzyl alcohol, 2,4-hexadienal isomers, and 4-methyl-2-hexanone, the differences only being significant for the last. However, if we considered each harvest independently, the volatile compound total content followed similar trends in both the 2019 and 2020 harvests, being higher in musts from organic than in conventional cultivation, although it was only statistically significant for the 2019 harvest. In the 2021 harvest, both kinds of musts presented a very similar volatile compound total content. The total content of nitrogen compounds was the only case in which we observed a significantly higher amount in organic than in conventional musts for every harvest studied. In the case of aldehydes and C 13 -norisoprenoinds total contents, organic musts also presented higher amounts, but significant differences between the two kinds of cultivations were only observed in the 2021 harvest. For the remaining chemical groups, in most cases, the total contents were higher in musts from organic cultivation for the 2019 and 2020 harvests and in musts from conventional cultivation for the 2021 harvest. Among them, we can highlight the case of acetic acid esters, ketones, lactones, methyl esters and other esters groups which showed significantly different results for the three harvests (Fig. 3S). Regarding the content of each volatile compound from the major chemical groups, alcohols, aldehydes, and ketones, we observed significantly different amounts for most of them, depending on the kind of cultivation. These amounts were higher in organic than conventional musts in 2019 and 2020 and contrariwise in the 2021 harvest for most of them. In the case of alcohols, 1-hexanol, trans-3-hexanol, cis-3-hexen-1- ol, trans-2-hexen-1-ol, and cis-2-hexen-1-ol, responsible for herbaceous aroma, and 1-octen-3-ol, 1-heptanol, 2-ethyl-1-hexanol, 1-octanol, trans-2-octen-1-ol, and furfuryl alcohol, they were significantly more abundant in organic musts in the 2019 and 2020 harvests and in musts from conventional cultivation in the 2021 harvest. In the case of furanic aldehydes (2-furfuraldehyde, 5-methyl-2-furfuraldehyde, 5-hydrox- ymethylfurfural, and 3-furfuraldehyde), the same trend was observed. The same occurred in the case of ketones such as diacetyl, 1-hydroxy-2- propanone, 1-hydroxy-2-butanone, 2-acetylfuran, 3-methyl-2-cyclo- penten-1-one and 2-cyclopentene-1,4-dione, in the case of diacetyl, there was no significant difference between crop types in the 2019 harvest. This also occurred in other minor chemical groups such as the group of acids. However, 2-heptanal, trans-2-nonenal, and nonanal were significantly more abundant in organic musts in the three harvests (with the exception of nonanal in the last harvest). These compounds provided herbaceous and fatty or waxy aromas. Regarding ketones, the contents were higher in organic musts in the three harvests for 2,6-dimethyl-4- heptanone and 6-methyl-5-hepten-2-one, with chemical and citric aromatic notes, respectively. Moreover, a higher number of terpenes were significantly more abundant in organic than in conventional musts in each harvest, with a similar trend in the three harvests only in the case of cis-linalool oxide. When they studied the evolution of free terpenes in several grape varieties, Luo et al. (2019), also found differences between harvests. Although there were few samples, a PCA considering the volatile profile of musts from conventional and organic cultivation of the three harvests was performed. The first three PCs explained 81.8 % of the total variance of the data. As can be seen in Fig. 1, PC1 separated the samples of the 2019 harvest from those of the other two harvests and PC2 separated the samples of the 2020 and 2021 harvests. The musts from vines cultivated using the conventional method were located closer to each other than those from organic cultivation. If we consider PC3, this E. Valero et al. Food Research International 160 (2022) 111694 4 Table 1 Volatile profiles of grape musts from vines submitted to different agronomic conditions in three consecutives harvests. Relative peak area* ± SD † Volatile Compounds ID Harvest SC SELL SELZ SEZZ SE4Z Acids Acetic acid A 19 0.0049 ±0.0010 a 0.0098 ±0.0012 b 0.00301 ±0.00016 a 0.00966 ±0.00014 b 0.0098 ±0.0010 b 20 0.0071 ±0.0008 c 0.0090 ±0.0010 d 0.00392 ±0.00005 a 0.0052 ±0.0004 b 0.00415 ±0.00007 a 21 0.0146 ±0.0013 c 0.0038 ±0.0005 b 0.00189 ±0.00013 a – – Propanoic acid A 19 – 0.00243 ± 0.00005ª ,b – 0.00238 ±0.00015 a 0.0028 ±0.0003 b 20 – – – – – 21 – – – – – Hexanoic acid A 19 0.0086 ±0.0013 a 0.023 ±0.003 b 0.0036 ±0.0005 a 0.0226 ±0.0019 b 0.036 ±0.003 c 20 0.00212 ±0.00018 a 0.0049 ±0.0007 b 0.0112 ±0.0015 c 0.0049 ±0.0004 b 0.0042 ±0.0004 b 21 0.0031 ±0.0005 – – – – 2-Ethylhexanoic acid B 19 0.0022 ±0.0005 a,b 0.0048 ±0.0007 c 0.00131 ±0.00023 a 0.00245 ±0.00019 a, b 0.00425 ±0.00017 b, c 20 – – 0.0022 ±0.0004 a,b 0.0019 ±0.0004 a,b 0.0017 ±0.0002 b 21 – – – – – Total of acids 19 0.016 ±0.007 a 0.041 ±0.003 b 0.0079 ±0.0004 a 0.0371 ±0.0021 b 0.0532 ±0.0017 c 20 0.0092 ±0.0009 b 0.01391 ± 0.00019 a,b 0.0173 ±0.0019 a 0.0120 ±0.003 a,b 0.010 ±0.006 a,b 21 0.0177 ±0.0008 a 0.0038 ±0.0005 b 0.00189 ±0.00013 c – – Acetic Acid Esters Methyl acetate A 19 0.0069 ±0.0009 a 0.028 ±0.003 c 0.0156 ±0.0016 b 0.040 ±0.004 d 0.0482 ±0.0006 e 20 0.0111 ±0.0015 a 0.0162 ±0.003 b 0.037 ±0.003 e 0.020 ±0.003 c 0.0265 ±0.0021 d 21 0.00191 ±0.00019 a 0.00128 ±0.00019 a 0.0085 ±0.0013 b 0.0208 ±0.0003 d 0.0169 ±0.0024 c Ethyl acetate A 19 0.027 ±0.004 a,b 0.054 ±0.008 b 0.00807 ±0.0012 a 0.0042 ±0.0006 a 0.0243 ±0.0013 a,b 20 0.0110 ±0.0005 a 0.036 ±0.004 b 0.028 ±0.004 b,c 0.0179 ±0.0011 a 0.0268 ±0.0004 b 21 0.023 ±0.003 c 0.0056 ±0.0004 a 0.00449 ±0.00016 a 0.0081 ±0.0012 a 0.0154 ±0.0013 b Butyl acetate A 19 – 0.00122 ± 0.00011 b 0.00071 ±0.00002 a – – 20 – – – – – 21 – – – – – Hexyl acetate A 19 0.0027 ±0.0003 a,b 0.0049 ±0.0003 d 0.00349 ±0.00010 c 0.003199 ± 0.000006 b,c 0.00243 ±0.00007 a 20 0.0039 ±0.0004 a 0.0074 ±0.0008 d 0.0056 ±0.0006 c 0.00496 ±0.00011 b 0.005358 ± 0.000005 b,c 21 – – – – – cis-3-hexenyl acetate A 19 0.0034 ±0.0003 d 0.00102 ±0.00009 a 0.00148 ±0.00021 b, c 0.00186 ±0.00005 c 0.00109 ±0.00007 a, b 20 0.00195 ± 0.00005 b – 0.00231 ±0.00013 c 0.0025 ±0.0006 d 0.00140 ±0.00007 a 21 – – – – – 2-Hexenyl acetate B 19 0.00262 ± 0.00021ª ,b 0.0032 ±0.0004 b 0.0048 ±0.0007 c 0.00154 ±0.00023 a 0.0049 ±0.0003 b 20 – 0.00300 ±0.00016 c 0.00161 ±0.00019 a 0.00197 ±0.00012 b 0.00169 ±0.00011 a 21 – – – – – 2-Phenylethyl acetate B 19 0.00096 ± 0.00004 b 0.001214 ± 0.000013 c 0.00063 ±0.00009 a 0.00106 ±0.00013 b, c 0.00091 ±0.00011 b 20 – – – – – 21 – – – – – Total of acetic acid esters 19 0.044 ±0.017 b 0.094 ±0.019 a 0.0348 ±0.0012 b 0.0514 ±0.0014 b 0.082 ±0.003 a 20 0.0279 ±0.023 c 0.0620 ±0.0004 a 0.074 ±0.011 a 0.047 ±0.003 b 0.0618 ±0.0018 a 21 0.025 ±0.003 b 0.00685 ± 0.00016 d 0.0130 ±0.0014 c 0.0289 ±0.0015ª ,b 0.03 ±0.04 a Alcohols Methanol A 19 0.062 ±0.009 a 0.065 ±0.007 a 0.25 ±0.04 b 0.045 ±0.006 a 0.082 ±0.012 a 20 0.095 ±0.003 d 0.034 ±0.005 b 0.134 ±0.012 e 0.046 ±0.010 c 0.0220 ±0.0008 a 21 0.0107 ±0.0003 a 0.0064 ±0.0007 a 0.029 ±0.004 b 0.035 ±0.005 b 0.06746 ±0.00016 c Isobutanol A 19 0.0078 ±0.0008 a 0.024 ±0.003 b 0.00888 ±0.00005 a 0.013 ±0.003 a 0.0084 ±0.0013 a 20 0.00147 ±0.00004 a 0.0060 ±0.0010 a 0.006 ±0.003 a 0.00395 ±0.00019 a 0.022 ±0.008 b 21 – – – – – 1-Butanol A 19 0.018 ±0.003 a 0.0181 ±0.0005 a 0.011 ±0.0004 b 0.0097 ±0.0003 b 0.0179 ±0.0018 b 20 0.0114 ±0.0014 b 0.0147 ±0.0022 c 0.006 ±0.0006 a 0.0175 ±0.0005 d 0.0170 ±0.0017 d 21 0.0234 ±0.0008 d 0.00880 ± 0.00019 b 0.0058 ±0.0006 a 0.0083 ±0.0004 b 0.0127 ±0.0005 c 1-Penten-3-ol B 19 0.0167 ±0.0004 b,c 0.010 ±0.003 a 0.0089 ±0.0020 a,b 0.0146 ±0.003 c 0.016 ±0.003 c 20 0.0143 ±0.0011 a 0.026 ±0.003 c 0.024 ±0.003 c 0.01969 ±0.00003 b 0.020 ±0.003 b 21 0.0109 ±0.0004 b 0.0109 ±0.0009 b 0.0095 ±0.0006ª ,b 0.0084 ±0.0006 a 0.0105 ±0.0006 b 2-Methyl-1-butanol A 19 0.0072 ±0.0011 b,c 0.0109 ±0.0022 c – 0.00449 ±0.00022 a, b 0.0067 ±0.0004 b,c 20 – – – – – 21 0.00346 ±0.00004 – – – – 3-Methyl-1-butanol A 19 0.02702 ± 0.00023 a,b 0.042 ±0.006 b 0.0170 ±0.0003 a 0.021 ±0.003 a 0.021 ±0.003 a 20 – 0.084 ±0.013 c 0.0472 ±0.0014 a 0.043 ±0.006 a 0.0620 ±0.0024 b (continued on next page) E. Valero et al. Food Research International 160 (2022) 111694 5 Table 1 (continued) Relative peak area* ± SD † Volatile Compounds ID Harvest SC SELL SELZ SEZZ SE4Z 21 0.0179 ±0.0018 c 0.0032 ±0.0005 a 0.0044 ±0.0005 a 0.0103 ±0.0014 b 0.0087 ±0.0011 b 2-Hexanol B 19 0.004446 ± 0.000024 a 0.005144 ± 0.000009 c 0.00430 ±0.00014 a 0.004827 ± 0.000015 b 0.004301 ± 0.000017 a 20 0.006171 ± 0.000013 c 0.00596 ± 0.00006 b 0.0054 ±0.0003 a 0.00540 ±0.00011 a 0.00553 ±0.00003 a 21 0.00539 ±0.00005ª 0.0054 ±0.0003 a 0.00523 ±0.00012 a 0.005434 ± 0.000003 a 0.00509 ±0.00003 a 5-Methyl-3-hexanol C 19 0.00473 ±0.00009 – – – – 20 0.00584 ±0.00020 a 0.006129 ± 0.000012 b 0.00633 ±0.00015 b, c 0.0065 ±0.0003 c 0.00620 ±0.00009 b 21 0.00481 ±0.00006 a 0.00524 ± 0.00014 b 0.00541 ±0.00005 b 0.00541 ±0.00016 b 0.00522 ±0.00013 b 1-Hexen-3-ol B 19 – 0.00149 ±0.00020 a 0.00245 ±0.00015 b 0.00172 ±0.00025ª 0.00152 ±0.00019 a 20 0.017 ±0.003 c 0.0083 ±0.0002 b 0.0027 ±0.0003 a 0.0093 ±0.0007 b 0.0040 ±0.0006 a 21 – – – – – 1-Pentanol B 19 0.0102 ±0.0012 c 0.00710 ± 0.00012 b 0.0046 ±0.0004 a 0.00533 ±0.00008 a 0.0075 ±0.0008 b 20 0.0063 ±0.0004 a 0.0096 ±0.0006 b 0.0110 ±0.0011 c 0.00615 ±0.00005 a 0.0100 ±0.0006 b 21 0.0096 ±0.0004 a 0.0166 ±0.0024 b 0.0090 ±0.0005 a 0.0089 ±0.0004 a 0.0099 ±0.0003 a cis-2-Penten-1-ol B 19 0.0167 ±0.0019 b 0.0096 ±0.0005 a 0.0089 ±0.0012 a 0.0146 ±0.0011 b 0.0159 ±0.0017 b 20 0.0069 ±0.0003 a 0.011326 ± 0.000015 d 0.0081 ±0.0004 b 0.0107 ±0.0006 c 0.0114 ±0.0003 d 21 0.00481 ±0.00015 a 0.0072 ±0.0011 b 0.0046 ±0.0003 a 0.00508 ±0.00021 a 0.00503 ±0.00002 a 2-Heptanol B 19 0.01567 ±0.00021 a 0.0082 ±0.0005 a 0.0095 ±0.0007 a 0.0084 ±0.0005 a 0.032 ±0.005 b 20 0.0088 ±0.0005 d 0.01406 ±0.00004 e 0.00566 ±0.00003 b 0.0045 ±0.0003 a 0.0061 ±0.0004 c 21 0.0057 ±0.0003 d 0.0045 ±0.0005 c 0.00139 ±0.00019 a 0.00210 ±0.00021 a 0.0032 ±0.0004 b 1,2-Butanediol C 19 0.00105 ±0.00013 a 0.00128 ±0.00008 a 0.00098 ±0.00007 a 0.001010 ± 0.000061 a 0.00126 ±0.00019 a 20 – 0.001998 ± 0.000022 b 0.00135 ±0.00014 a – – 21 – – – – – 1-Hexanol A 19 3.6 ±0.4 a 4.82 ±0.18 b 3.8 ±0.4 a 3.64 ±0.18 a 3.74 ±0.11 a 20 3.51 ±0.03 a 4.9 ±0.6 c 5.52 ±0.11 d 4.36 ±0.11 b 4.6 ±0.4 b,c 21 2.82 ±0.11 b 2.1 ±0.3 a 2.00 ±0.24 a 1.9 ±0.8 a 2.00 ±0.08 a trans-3-Hexanol B 19 0.0295 ±0.0012 a 0.02713 ±0.00021 a 0.0361 ±0.0007 b 0.0513 ±0.0011 d 0.044 ±0.005 c 20 0.0310 ±0.0021 a 0.039 ±0.003 c 0.0357 ±0.0013 b 0.0330 ±0.0007 a 0.0409 ±0.0021 c 21 0.0153 ±0.0006 c 0.0087 ±0.0006ª ,b 0.0074 ±0.0011 a 0.0094 ±0.0015ª ,b 0.0101 ±0.0003 b cis-3-Hexan-1-ol A 19 0.46 ±0.07 a,b 0.31 ±0.05 a 0.47 ±0.04 a,b 0.73 ±0.03 c 0.53 ±0.08 b 20 0.21 ±0.03 a 0.23 ±0.03 a 0.433 ±0.018 c 0.419 ±0.016 c 0.268 ±0.010 b 21 0.1424 ±0.0018 c 0.080 ±0.008 a 0.132 ±0.008 b,c 0.095 ±0.009 a 0.125 ±0.004 b trans-2-Hexen-1-ol A 19 3.05 ±0.14 a 3.314 ±0.019 a 3.23 ±0.21 a 2.76 ±0.07 a 3.8 ±0.6 a 20 2.994 ±0.004 a,b 2.6 ±0.4 a 4.1 ±0.4 d 3.7 ±0.5 c 3.24 ±0.18 b 21 1.290 ±0.017 c 0.95 ±0.14 b 0.66 ±0.05 a 1.01 ±0.12 b 1.144 ±0.023 b,c cis-2-Hexen-1-ol B 19 0.02012 ±0.00012 a 0.0204 ±0.0008 a 0.0307 ±0.0018 b 0.061 ±0.005 d 0.047 ±0.003 c 20 0.022 ±0.003 a 0.0214 ±0.0016 a 0.0278 ±0.0006 b 0.0224 ±0.0004 a 0.0263 ±0.0021 b 21 0.006 ±0.006 c 0.00235 ±0.00023 a 0.0031 ±0.0004ª ,b 0.0029 ±0.0002ª ,b 0.003463 ± 0.000008 b 1-Octen-3-ol A 19 0.0265 ±0.0008 a 0.0332 ±0.0020 a,b 0.063 ±0.012 b 0.035 ±0.004 a,b 0.0502 ±0.0075 a,b 20 0.0138 ±0.0014 a 0.041 ±0.004 c 0.01539 ±0.0019 a 0.0286 ±0.0016 b 0.030 ±0.005 b 21 0.027 ±0.004 b 0.0128 ±0.0017 a 0.0153 ±0.0023 a 0.017 ±0.003 a 0.0171 ±0.0022 a 1-Heptanol A 19 0.0039 ±0.0003 a,b 0.0052 ±0.0007 c,d 0.00311 ±0.00022 a 0.00580 ±0.00014 d 0.0045 ±0.0004 b,c 20 0.0032 ±0.0003 a 0.0084 ±0.0012 c 0.00460 ±0.00024 b 0.0036 ±0.0005 a,b 0.00408 ±0.00007 a, b 21 0.00417 ±0.00020 c 0.00232 ± 0.00007 b 0.00196 ±0.00009 a 0.00177 ±0.00009 a 0.00195 ±0.00014 a 2-Ethyl-1-hexanol A 19 0.0135 ±0.0020 b 0.034 ±0.003 c 0.0100 ±0.0007a,b 0.0109 ±0.0008 a,b 0.00783 ±0.00007 a 20 0.0203 ±0.0023 a 0.0313 ±0.0022 b 0.0327 ±0.0018 b 0.036 ±0.003 c 0.0312 ±0.0016 b 21 0.034 ±0.004 c 0.0227 ±0.0019 b 0.018 ±0.003ª ,b 0.0136 ±0.0003 a 0.0140 ±0.0010 a 1-Octanol A 19 0.00347 ±0.00005 a 0.0057 ±0.0007 b 0.00365 ±0.00017 a 0.0037 ±0.0003 a 0.00411 ±0.00013 a 20 0.00349 ±0.00004 a 0.0095 ±0.0016 d 0.0059 ±0.0004 c 0.00445 ±0.00014 a, b 0.00494 ±0.00013 b 21 0.00547 ± 0.00017 b 0.0035 ±0.0004 a 0.0070 ±0.0004 c 0.0058 ±0.0008 b 0.00396 ±0.00008 a trans-2-Octen-1-ol B 19 0.00125 ±0.00007 a 0.00205 ± 0.00018 b 0.00137 ±0.00009 a 0.0017 ±0.0003 a,b 0.00145 ±0.00022 a, b 20 0.00136 ±0.00011 a 0.0043 ±0.0005 d 0.00325 ±0.00005 c 0.00225 ±0.00013 b 0.00318 ±0.00007 c 21 0.00239 ± 0.00008 b,c 0.00175 ±0.00002 a 0.0027 ±0.0004 c 0.00157 ±0.00021 a 0.00191 ±0.00013ª , b 1-Nonanol B 19 0.00214 ±0.00021 a 0.0053 ±0.0003 c 0.00273 ±0.00023 a 0.0042 ±0.0006 b 0.00356 ±0.00005 b 20 0.00369 ±0.00015 a 0.0101 ±0.0015 d 0.0066 ±0.0003 c 0.00519 ±0.00006 b 0.0048 ±0.0004 b 21 0.00409 ±0.00013 a 0.00371 ±0.00011 a 0.0058 ±0.0003 b 0.0056 ±0.0008 b 0.00396 ±0.00013 a Furfuryl alcohol A 19 0.056 ±0.006 b 0.0785 ±0.0009 c 0.033 ±0.003 a 0.056 ±0.004 b 0.0570 ±0.0016 b 20 0.0215 ±0.0005 a 0.062 ±0.007 d 0.0441 ±0.0003 c 0.0386 ±0.0017 b 0.026 ±0.004 a 21 0.050 ±0.007 b 0.027 ±0.004 a 0.0261 ±0.0006 a 0.028 ±0.003 a 0.0199 ±0.0019 a (continued on next page) E. Valero et al. Food Research International 160 (2022) 111694 6 Table 1 (continued) Relative peak area* ± SD † Volatile Compounds ID Harvest SC SELL SELZ SEZZ SE4Z 1-Decanol B 19 0.000827 ± 0.000024 a 0.00162 ± 0.00008 b 0.00097 ±0.00007 a 0.00408 ±0.00011 c – 20 – – – – – 21 – – – – – Benzyl alcohol A 19 0.029 ±0.003 a 0.0175 ±0.0007 a 0.022 ±0.003 a 0.0314 ±0.0003 a,b 0.041 ±0.003 b 20 0.0134 ±0.0018 d 0.0072 ±0.0005 a 0.0086 ±0.0011 a,b 0.0096 ±0.0016 b,c 0.0106 ±0.0014 c 21 0.0144 ±0.0004 d 0.0087 ±0.0010 c 0.00395 ±0.00022 a 0.0061 ±0.0005 b 0.00472 ±0.00019ª , b 2-Phenylethanol A 19 0.131 ±0.007 b,c 0.087 ±0.005 a,b 0.058 ±0.009 a 0.163 ±0.010 c 0.17 ±0.03 c 20 0.06285 ± 0.00017 b 0.079 ±0.003 c 0.0462 ±0.0004 a 0.041 ±0.003 a 0.070 ±0.010 b,c 21 0.0401 ±0.0022 c 0.0152 ±0.0012 a 0.01393 ±0.00011 a 0.0176 ±0.0003ª ,b 0.022 ±0.003 b 1-Dodecanol B 19 0.0212 ±0.0019 d 0.0199 ±0.0024 c,d 0.01698 ±0.00003 b, c 0.009819 ± 0.000015 a 0.0157 ±0.0018 b 20 0.00734 ±0.00004 a 0.0060 ±0.0007 a 0.019 ±0.003 c 0.00957 ±0.00008 b 0.0095 ±0.0013 b 21 0.0129 ±0.0016 a 0.01625 ±0.00005 a 0.0172 ±0.0021 a 0.031 ±0.005 b 0.0127 ±0.0008 a 1-Tridecanol B 19 0.00107 ±0.00008 a 0.00190 ±0.00021 c 0.00101 ±0.00008 a 0.00128 ±0.00004 a, b 0.00161 ±0.00015 b, c 20 0.001518 ± 0.000009 a 0.0016 ±0.0003 a 0.00221 ±0.00021 b 0.00169 ±0.00013 a 0.00167 ±0.00023 a 21 0.0017 ±0.0003 b – 0.00117 ±0.00017 a 0.00149 ±0.00007 a, b – 1-Tetradecanol B 19 0.0104 ±0.0006 b 0.0097 ±0.0011 b 0.0128 ±0.0014 c 0.00526 ±0.00003 a 0.0096 ±0.0007 b 20 0.0044 ±0.0004 a 0.0054 ±0.0005 a,b 0.0084 ±0.0015 c 0.0053 ±0.0003 a,b 0.0057 ±0.0009 b 21 0.0088 ±0.0010ª 0.0078 ±0.0003ª 0.0089 ±0.0007ª 0.0090 ±0.0010ª 0.00895 ±0.00022ª 1-Heptadecanol C 19 0.00132 ± 0.00007 b 0.0017 ±0.0003 c 0.00092 ±0.00011 a 0.00128 ±0.00005 a, b 0.00136 ±0.00015 b, c 20 – – 0.00129 ±0.00011 – – 21 0.00143 ±0.00008 a 0.0024 ±0.0003 b 0.00131 ±0.00019 a – 0.0026 ±0.0003 b Total of alcohols 19 7.64 ±0.22 a 9.0 ±0.3 a 8.1 ±0.7 a 7.74 ±0.15 a 8.7 ±1.4 a 20 7.10 ±0.06 c 8.3 ±1.0 b,c 10.6 ±0.5 a 8.9 ±0.6 b 8.6 ±0.5 b,c 21 4.58 ±0.11 a 3.36 ±0.47 b 3.00 ±0.18 b 3.24 ±0.17 b 3.53 ±0.09 b Aldehydes 2-Methyl-butanal B 19 0.00983 ±0.00005 c 0.0110 ±0.0012 c 0.0072 ±0.0006 b 0.0054 ±0.0005 a,b 0.0041 ±0.0005 a 20 0.046 ±0.005 c 0.038 ±0.005 b 0.0521 ±0.0005 d 0.0258 ±0.0024 a 0.0255 ±0.0011 a 21 0.0088 ±0.0010 b 0.00558 ±0.00013 a 0.0065 ±0.0003 a 0.0071 ±0.0010 a 0.0107 ±0.0003 b 3-Methyl-1-butanal B 19 0.009819 ± 0.000015 c 0.0112 ±0.0006 c 0.0069 ±0.0006 b 0.0055 ±0.0008 b 0.0037 ±0.0005 a 20 0.044 ±0.005 b 0.045 ±0.005 b 0.0427 ±0.0011 b 0.027 ±0.003 a 0.0266 ±0.0009 a 21 0.0090 ±0.0006 b 0.0042 ±0.0005 a 0.0055 ±0.0003 a 0.0057 ±0.0004 a 0.0097 ±0.0012 b Pentanal B 19 0.00240 ± 0.00003 a,b 0.00201 ±0.00018 a 0.0025 ±0.0004 a,b 0.0028 ±0.0003 b 0.00266 ±0.00013 b 20 0.00320 ±0.00019 a 0.00706 ±0.00008 c 0.00947 ±0.00012 d 0.00670 ±0.00011 b 0.00666 ±0.00005 b 21 0.00386 ±0.00004 a 0.00968 ± 0.00018 d 0.0074 ±0.0003 b,c 0.00755 ±0.00006 c 0.00712 ±0.00003 b Hexanal A 19 0.356 ±0.018 c 0.348 ±0.012 c 0.18 ±0.03 b 0.089 ±0.004 a 0.039 ±0.018 a 20 0.322 ±0.014 c 0.117 ±0.005 a 0.36 ±0.04 c 0.523 ±0.011 d 0.201 ±0.010 b 21 0.84 ±0.05ª 1.6 ±0.3 b 1.38 ±0.19 b 1.20 ±0.16ª ,b 1.37 ±0.19 b trans-3-Hexenal B 19 0.0061 ±0.0008 c 0.0034 ±0.0005 a 0.0057 ±0.0004 b,c 0.004428 ± 0.000009 a,b 0.0050 ±0.0007 b,c 20 0.0048 ±0.0004 b 0.0085 ±0.0007 c 0.0059 ±0.0003 b 0.0083 ±0.0010 c 0.00259 ±0.00020 a 21 0.00641 ±0.00007 a 0.00595 ±0.00077 a 0.01788 ±0.00234 c 0.01431 ±0.00022 b 0.01679 ±0.00062 b, c cis-3-Hexenal B 19 0.00228 ± 0.00023 b 0.0022 ±0.0004 b 0.001359 ± 0.000005 a 0.00243 ±0.00013 b 0.00144 ±0.00020 a 20 0.00160 ±0.00024 a 0.00182 ± 0.00011 b 0.00158 ±0.00009 a – – 21 0.00178 ±0.00020 a 0.0032 ±0.0005ª ,b 0.0085 ±0.0010 d 0.0045 ±0.0005 b,c 0.00587 ±0.00021 c Heptanal A 19 – – – – – 20 – – – – – 21 – – – 0.00166 ±0.00007 b 0.00014 ±0.00019 a trans-2-Hexenal B 19 0.0099 ±0.0013 a,b, c 0.0102 ±0.0015 b,c 0.0116 ±0.0016 c 0.00624 ±0.00022 a 0.0068 ±0.0010 a,b 20 0.01067 ±0.00016 c 0.013 ±0.003 d 0.01369 ±0.00009 d 0.0087 ±0.0013 b 0.0069 ±0.0006 a 21 0.0164 ±0.0008 a 0.0169 ±0.0010 ª,b 0.038 ±0.004 c 0.0239 ±0.0016 b 0.033 ±0.005 c cis-2-Hexenal B 19 0.37 ±0.07 a 0.415 ±0.007 a 0.38 ±0.05 a 0.30 ±0.04 a 0.27 ±0.04 a 20 0.2842 ±0.0012 a 0.32 ±0.05 a 0.375 ±0.021 a 0.305 ±0.017 a 0.192 ±0.005 a 21 0.602 ±0.003 a,b 0.60 ±0.04ª ,b 1.06 ±0.16 c 0.53 ±0.08 a 0.81 ±0.12 b Octanal A 19 – 0.0024 ±0.0003 b 0.00075 ±0.00010 a 0.000921 ± 0.000016 a 0.00085 ±0.00010 a 20 – – 0.00116 ±0.00016 a 0.00145 ±0.00014 b – 21 0.001396 ± 0.000021 a 0.00124 ±0.00014 a 0.0027 ±0.0004 b 0.00330 ±0.00015 c 0.00122 ±0.00009 a 2-Heptenal A 19 0.00088 ±0.00003 a 0.0056 ±0.0008 b 0.00103 ±0.00005 a 0.00196 ±0.00021 a 0.0045 ±0.0007 b (continued on next page) E. Valero et al. Food Research International 160 (2022) 111694 7 Table 1 (continued) Relative peak area* ± SD † Volatile Compounds ID Harvest SC SELL SELZ SEZZ SE4Z 20 0.00134 ±0.00007 a 0.0045 ±0.0006 c 0.0030 ±0.0004 b 0.00406 ±0.00021 c 0.0026 ±0.0003 b 21 0.00393 ±0.00020 a 0.0078 ±0.0012 b 0.0082 ±0.0009 b 0.0066 ±0.0009 b 0.0045 ±0.0004 a Nonanal B 19 0.0023 ±0.0003 a 0.0044 ±0.0005 b 0.0019 ±0.0003 a 0.00217 ±0.00005 a 0.0024 ±0.0003 a 20 0.00126 ±0.00011 a 0.00389 ± 0.00019 d 0.00345 ±0.00004 c 0.0035 ±0.0004 c 0.00247 ±0.00003 b 21 0.00615 ±0.00022 a 0.0068 ±0.0007 a 0.0129 ±0.0018 b 0.0119 ±0.0014 b 0.0081 ±0.0010 a 2,4-Hexadienal isomers sum 19 0.0052 ±0.0004 c 0.0045 ±0.0007 c 0.0043 ±0.0007 b,c 0.00218 ±0.00011 a 0.00277 ±0.00010 a, b 20 0.0202 ±0.0022 d 0.014 ±0.003 b 0.01261 ±0.00012 b 0.0170 ±0.0014 c 0.0060 ±0.0008 a 21 0.0052 ±0.0005 a 0.0048 ±0.0003 a 0.0112 ±0.0013 c 0.00729 ±0.00007 b 0.0101 ±0.0009 c 3-Furfuraldehyde C 19 0.00293 ± 0.00014 b 0.0050 ±0.0005 d 0.00213 ±0.00016 a 0.00367 ±0.00008 c 0.00315 ±0.00004 b, c 20 0.00160 ±0.00008 a 0.00253 ±0.00015 c 0.00209 ±0.00024 b 0.00249 ±0.00010 c 0.00198 ±0.00013 b 21 0.00355 ±0.00015 c 0.0033 ±0.0003 c 0.0028 ±0.0003 b 0.00166 ±0.00004 a 0.001730 ± 0.000005 a trans-2-Octenal A 19 – 0.00177 ±0.00018 – – – 20 – – 0.0021 ±0.0003 b 0.00293 ±0.00018 c 0.00159 ±0.00006 a 21 – – 0.0031 ±0.0004 b 0.00235 ±0.00022 a – 2-Furfuraldehyde A 19 0.071 ±0.005 c 0.1161 ±0.0008 d 0.0337 ±0.0019 a 0.0585 ±0.0013 b 0.055 ±0.003 b 20 0.0425 ±0.0020 a 0.098 ±0.020 c 0.074 ±0.003 b 0.064 ±0.009 b 0.034 ±0.006 a 21 0.099 ±0.008 c 0.043 ±0.006 b 0.043 ±0.006 b 0.0244 ±0.0008 a 0.0342 ±0.0006ª ,b trans,cis-2,4-Heptadienal B 19 0.00192 ± 0.00017 a,b 0.0028 ±0.0003 b 0.00162 ±0.00010 a 0.00227 ±0.00010 a, b 0.0022 ±0.0003 a,b 20 0.00160 ±0.00011 a 0.0043 ±0.0003 b 0.0049 ±0.0003 c 0.00443 ±0.00021 b 0.00444 ±0.00003 b 21 0.0029 ±0.0004ª ,b 0.0038 ±0.0006 b,c 0.0043 ±0.0005 c 0.00339 ±0.00014ª , b,c 0.00278 ±0.00014ª trans,trans-2,4-Heptadienal B 19 0.0037 ±0.0003 a,b 0.0029 ±0.0005 b 0.00136 ±0.00020 a 0.0020 ±0.0003 a,b 0.0023 ±0.0005 a,b 20 0.00322 ±0.00020 a 0.00466 ± 0.00007 b 0.0055 ±0.0003 c 0.0068 ±0.0009 d 0.00428 ±0.00023 b 21 0.00349 ±0.00026 a 0.00435 ±0.0003ª ,b 0.00449 ±0.00053ª , b 0.006206 ± 0.00087 b,c 0.00516 ±0.0006 c Decanal A 19 – 0.00236 ± 0.00003 b – 0.00106 ±0.00014 a – 20 – – – – – 21 0.00292 ±0.00037 a 0.00421 ±0.0006 a 0.0034 ±0.00029 a 0.00956 ±0.00128 b 0.00436 ±0.00055 a Benzaldehyde A 19 0.01035 ±0.00005 a 0.024 ±0.003 b 0.0107 ±0.0010 a 0.0084 ±0.0004 a 0.0096 ±0.0013 a 20 0.0165 ±0.0025 a 0.0158 ±0.0014 a 0.0140 ±0.0019 a 0.0155 ±0.0020 a 0.038 ±0.002 b 21 0.0151 ±0.0017 b 0.00984 ±0.00017 a 0.0090 ±0.0003 a 0.00997 ±0.00003 a 0.0102 ±0.0005 a trans-2-Nonenal B 19 – 0.001053 ± 0.000024 – – – 20 – 0.00143 ± 0.00005 b – 0.00174 ±0.00021 c 0.00124 ±0.00015 a 21 0.00134 ±0.00003 c 0.00153 ±0.00007 a 0.00237 ±0.00013 c 0.0020 ±0.0003 b 0.00121 ±0.00011 d 5-Methyl-2-furfuraldehyde A 19 0.00749 ± 0.00011 d 0.0090 ±0.0007 e 0.003795 ± 0.000017 a 0.00510 ±0.00024 b 0.0061 ±0.0004 c 20 0.00606 ±0.00017 a 0.0135 ±0.0020 b 0.0140 ±0.0024 b 0.019 ±0.003 b 0.004560 ± 0.00016 a 21 0.00174 ±0.0003 c 0.00655 ± 0.00007 b 0.0067 ±0.0009 b 0.0030 ±0.0004 a 0.00317 ±0.00014 a cis-2-Decenal A 19 – 0.00237 ± 0.00014 b – 0.00115 ±0.00013 a 0.000936 ± 0.000022 a 20 – – – – – 21 0.0017 ±0.0003 a 0.00133 ±0.00003 a 0.0056 ±0.0008 b 0.00641 ±0.00018 b 0.00205 ±0.00020 a trans,trans-2,4-Nonadienal B 19 0.00076 ±0.00006 a 0.00191 ± 0.00010 b – – 0.00085 ±0.00003 a 20 0.0026 ±0.0004 c 0.0021 ±0.0003 b 0.00128 ±0.00011 a 0.008137 ± 0.000003 d 0.001967 ± 0.000003 b 21 – – 0.0054 ±0.0008 b 0.0039 ±0.0006 a – 2-Undecanal B 19 0.00101 ±0.00008 a 0.00354 ±0.00008 c 0.00104 ±0.00003 a 0.00133 ±0.00003 b 0.00112 ±0.00003 a 20 – – – – – 21 – – 0.0033 ±0.0005 b 0.0053 ±0.0008 c 0.00144 ±0.00014 a Safranal C 19 – – – – – 20 0.0035 ±0.0003 a 0.0129 ±0.0011 d 0.0054 ±0.0008 b 0.00698 ±0.00004 b, c 0.0070 ±0.0011 c 21 – – – – – 5-Hydroxymethylfurfural A 19 0.0096 ±0.0014 a 0.027 ±0.004 b 0.0090 ±0.0017 a 0.0091 ±0.0012 a 0.0138 ±0.0012 a 20 0.0122 ±0.0010 a 0.154 ±0.023 c 0.092 ±0.019 b 0.136 ±0.020 c 0.0140 ±0.0004 a 21 0.075 ±0.010 b 0.0102 ±0.0015 a 0.0129 ±0.0019 a 0.0044 ±0.0004 a 0.0062 ±0.0008 a Total of aldehydes 19 0.88 ±0.08 a 1.019 ±0.014 a 0.66 ±0.09 b 0.51 ±0.08 b,c 0.44 ±0.08 c 20 0.83 ±0.03 b,c 0.9 ±0.3 b,c 1.09 ±0.05 a,b 1.20 ±0.04 a 0.585 ±0.014 c 21 1.73 ±0.05 c 2.3 ±0.3ª ,b 2.7 ±0.4 a 1.9 ±0.7 b,c 2.36 ±0.10ª ,b Ethyl Esters Ethyl isovalerate A 19 0.000921 ± 0.000013 a 0.00087 ±0.00004 a – – 0.00090 ±0.00009 a (continued on next page) E. Valero et al. Food Research International 160 (2022) 111694 8 Table 1 (continued) Relative peak area* ± SD † Volatile Compounds ID Harvest SC SELL SELZ SEZZ SE4Z 20 – – – – – 21 0.001239 ± 0.000015 b – – – – Ethyl hexanoate A 19 0.0007 ±0.0001 a 0.00133 ± 0.00019 a,b 0.00080 ±0.00005 a 0.00101 ±0.00006 a 0.0021 ±0.0003 b 20 0.00139 ±0.00011 a 0.0028 ±0.0003 c – 0.0022 ±0.0003 b 0.00355 ±0.00003 d 21 – – – – – Ethyl 4-ethoxybenzoate B 19 – – 0.00098 ±0.00003 a 0.00092 ±0.00005 a 0.0017 ±0.0006 b 20 – – – – – 21 0.048 ±0.007 b – – – 0.00129 ±0.00005 a Total of ethyl esters 19 0.00160 ± 0.00008 b 0.00220 ± 0.00014 b 0.001772 ± 0.000017 b 0.00193 ±0.00012 b 0.0048 ±0.0012 a 20 0.00139 ±0.00011 a 0.0028 ±0.0003 c – 0.0022 ±0.0003 b 0.00355 ±0.00003 d 21 0.049 ±0.007 a – – – 0.00129 ±0.00005 b Ketones Diacetyl A 19 0.0076 ±0.0006 a,b 0.00961 ± 0.00010 a,b 0.0037 ±0.0005 a 0.0085 ±0.0003 a,b 0.0107 ±0.0011 b 20 0.00558 ± 0.00003 a,b 0.0147 ±0.0016 d 0.0086 ±0.0010 c 0.0064 ±0.0003 b 0.0045 ±0.0006 a 21 0.00446 ± 0.00005 d 0.0035 ±0.0005 c 0.00259 ±0.00020 b 0.00175 ±0.00009 a 0.00207 ±0.00006ª , b 4-Methyl-2-pentanone A 19 0.0292 ±0.0007 b 0.02536 ±0.00010 a 0.0290 ±0.0015 b 0.0269 ±0.0020 a,b 0.0266 ±0.0008 a,b 20 0.050 ±0.004 c 0.0335 ±0.0004 a 0.0375 ±0.0019 b 0.0314 ±0.0009 a 0.0327 ±0.0014 a 21 0.03738 ± 0.00020 b 0.0407 ±0.0012 c 0.0338 ±0.0003 a 0.0340 ±0.0021 a 0.0368 ±0.0014ª ,b 2,3-Pentanedione A 19 0.00202 ± 0.00015 b 0.002692 ± 0.00017 c 0.00123 ±0.00021 a 0.002536 ± 0.000004 b,c 0.0034 ±0.0004 d 20 – 0.0063 ±0.0009 c 0.004050 ± 0.000017 b 0.0046 ±0.0007 b 0.001430 ± 0.000015 a 21 – – – – – 4-Methyl-2-hexanone C 19 0.00176 ± 0.00021 b,c 0.0011 ±0.0016 b,c 0.00183 ±0.00015 c 0.001469 ± 0.000023 a,b 0.00125 ±0.00003 a 20 0.00191 ± 0.00008 b 0.00147 ±0.00017 a 0.001892 ± 0.000016 b 0.00192 ±0.00007 b 0.00183 ±0.00010 b 21 0.00153 ± 0.00005 b 0.0015 ±0.00006 a 0.00155 ±0.00002 a 0.02671 ±0.00404 b 0.04656 ±0.00213 c 2,6-Dimethyl-4-heptanone A 19 0.00441 ±0.00006 a 0.0064 ±0.0003 b,c 0.0065 ±0.0003 c 0.0053 ±0.0005 a,b 0.0060 ±0.0006 b,c 20 0.00547 ±0.00023 a 0.0058 ±0.0005 a 0.0071 ±0.0005 b 0.0093 ±0.0009 c 0.0072 ±0.0012 b 21 0.0073 ±0.00108 a 0.0103 ±0.00111 b 0.00601 ±0.00002 a 0.00756 ±0.00015 a 0.0067 ±0.00084 a Acetoin A 19 0.053 ±0.008 a 0.045 ±0.007 a 0.024 ±0.004 a 0.026 ±0.004 a 0.18 ±0.03 b 20 0.028 ±0.004 a 0.124 ±0.003 d 0.059 ±0.009 b 0.104 ±0.014 c 0.106 ±0.010 c 21 0.07023 ±0.0104 d 0.02102 ± 0.00269ª ,b 0.01233 ±0.00002 a 0.02671 ±0.00404 b 0.04656 ±0.00213 c 1-Hydroxy-2-propanone A 19 0.053 ±0.007 b 0.085 ±0.004 d 0.0304 ±0.0006 a 0.0641 ±0.0005 c 0.066 ±0.003 c 20 0.0119 ±0.0004 a 0.060 ±0.003 e 0.042 ±0.003 d 0.0346 ±0.0005 c 0.022 ±0.003 b 21 0.04263 ± 0.00636 b 0.01101 ±0.00159 a 0.00917 ±0.00128 a 0.00548 ±0.00081 a 0.01197 ±0.00158 a 2,3-Octanedione C 19 0.00090 ±0.00004 a 0.00100 ±0.00008 a 0.00111 ±0.00017 a 0.00099 ±0.00015 a 0.00098 ±0.00018 a 20 0.00124 ±0.00018 a 0.00240 ± 0.00018 b 0.00142 ±0.00013 a 0.00223 ±0.00004 b 0.00226 ±0.00016 b 21 – – – 0.00186 ±0.00028 a 0.00166 ±0.00003 a 6-Methyl-5-hepten-2-one A 19 0.0033 ±0.0004 b 0.0074 ±0.0007 d 0.00248 ±0.00008 b 0.005239 ± 0.000005 c 0.00403 ±0.00011 b 20 0.0070 ±0.0005 c 0.0085 ±0.0010 d 0.00605 ±0.00021 b 0.0046 ±0.0007 a 0.0054 ±0.0005 a,b 21 0.00436 ±0.00039 a 0.00793 ± 0.00099 b 0.00497 ±0.00066 a 0.00725 ±0.00004 b 0.00671 ±0.00001 b 2-Cyclopenten-1-one A 19 0.00984 ± 0.00014 b 0.0141 ±0.0012 c 0.0063 ±0.0003 a 0.0115 ±0.0005 b 0.0107 ±0.0008 b 20 – – – – – 21 0.01015 ±0.00152 c 0.00949 ± 0.00058 b,c 0.00788 ±0.00069 b 0.00483 ±0.00025 a 0.00496 ±0.00015 a 1-Hydroxy-2-butanone A 19 0.0261 ±0.0015 b 0.0354 ±0.0010 c 0.020 ±0.003 a 0.02772 ±0.00019 b 0.0240 ±0.0010 b 20 0.0066 ±0.0004 a 0.0162 ±0.0015 d 0.0184 ±0.0006 e 0.0138 ±0.0005 c 0.0118 ±0.0016 b 21 0.01416 ±0.0021 b 0.00646 ±0.00073 a 0.00592 ±0.00082 a 0.00579 ±0.00073 a 0.00761 ±0.00023 a 2-Decanone A 19 0.001091 ± 0.000004 a 0.0021 ±0.0003 b 0.00092 ±0.00006 a – 0.000893 ± 0.000022 a 20 – – – – – 21 0.00225 ±0.00025 c 0.0018 ±0.00007 b 0.00136 ±0.00003 a 0.00167 ±0.00018ª ,b 0.00144 ±0.00001ª , b 2-Acetylfuran A 19 0.00929 ± 0.00003 b 0.0144 ±0.0003 d 0.007491 ± 0.000007 a 0.0143 ±0.0008 d 0.0126 ±0.0007 c 20 0.0050 ±0.0003 a 0.0107 ±0.0013 c 0.00764 ±0.00018 b 0.00800 ±0.00016 b 0.0045 ±0.0007 a 21 0.00939 ± 0.00007 d 0.00562 ±0.00008 c 0.0043 ±0.00062 b 0.00324 ±0.00017 a 0.00356 ±0.00004 a (continued on next page) E. Valero et al. Food Research International 160 (2022) 111694 9 Table 1 (continued) Relative peak area* ± SD † Volatile Compounds ID Harvest SC SELL SELZ SEZZ SE4Z 3-Methyl-2-cyclopenten-1-one C 19 0.00221 ± 0.00005 b 0.00279 ± 0.00011 d 0.00135 ±0.00008 a 0.00010 ±0.00018 c 0.00244 ±0.00005 c 20 0.00127 ±0.00004 a 0.0023 ±0.0003 c 0.00188 ±0.00018 b 0.00206 ±0.00005 b 0.00187 ±0.00021 b 21 0.00249 ± 0.00026 b 0.00202 ±0.00019 a 0.0017 ±0.00008 a – – 2-Cyclopentene-1,4-dione B 19 0.0036 ±0.0003 b 0.0058 ±0.0007 c 0.00234 ±0.00008 a 0.00363 ±0.00012 b 0.0060 ±0.0004 c 20 0.0029 ±0.0004 a 0.0234 ±0.0012 c 0.0121 ±0.0005 b 0.0139 ±0.0021 b 0.00266 ±0.00013 a 21 0.0159 ±0.00237 b 0.00391 ±0.00058 a 0.00332 ±0.00049 a 0.00191 ±0.00004 a 0.0015 ±0.00016 a 2-Acetyl-5-methylfuran A 19 0.00096 ±0.00011 a 0.0024 ±0.0003 c 0.00135 ±0.00005 b 0.001685 ± 0.000003 b 0.00135 ±0.00006 b 20 – – 0.00122 ±0.00004 a 0.0021 ±0.0003 b – 21 – – – 0.00124 ±0.00004 a 0.0015 ±0.00016 a 2-Undecanone A 19 – 0.00105 ± 0.00004 b 0.000786 ± 0.000010 a – – 20 – – – – – 21 – – – – – Acetophenone A 19 0.0074 ±0.0005 a 0.0165 ±0.0024 b 0.00689 ±0.00009 a 0.0060 ±0.0007 a 0.0064 ±0.0009 a 20 0.00704 ±0.00003 c 0.00507 ± 0.00005 b 0.0052 ±0.0006 b 0.0073 ±0.0009 c 0.0039 ±0.0007 a 21 0.10421 ±0.01549 c 0.05915 ± 0.00894 b 0.01058 ±0.00158 a 0.01256 ±0.00027 a 0.00832 ±0.0008 a 2-Hydroxy-2-cyclopenten-1-one C 19 0.0096 ±0.0003 a 0.037 ±0.005 c 0.0175 ±0.0021 b 0.0397 ±0.0020 c 0.0417 ±0.0015 c 20 – 0.0033 ±0.0003 a 0.00609 ±0.00016 b 0.0038 ±0.0006 a 0.0031 ±0.0004 a 21 – – – – – 4-Methyl-5H-furan-2-one B 19 0.00366 ± 0.00022 b 0.0039 ±0.0003 b 0.00280 ±0.00004 a 0.0043 ±0.0002 b 0.0039 ±0.0005 b 20 0.00184 ±0.00010 a 0.0044 ±0.0004 c 0.00328 ±0.00019 b 0.00332 ±0.00007 b 0.0020 ±0.0003 a 21 0.0024 ±0.00036ª ,b 0.0029 ±0.00038 b 0.00273 ±0.0002ª ,b 0.0021 ±0.0003 a 0.00209 ±0.00003 a Benzophenone C 19 0.00261 ± 0.00014 b 0.0033 ±0.0007 b 0.002617 ± 0.000011 b 0.001718 ± 0.000021 a 0.00297 ±0.00017 b 20 0.00238 ±0.00011 a 0.0026 ±0.0003 a,b 0.0044 ±0.0004 d 0.0029 ±0.0003 b,c 0.0032 ±0.0003 c 21 0.00304 ± 0.00006 b,c 0.00327 ±0.00048 c 0.00249 ±0.00016ª , b 0.00216 ±0.00016 a 0.00349 ±0.00033 c Total of ketones 19 0.23 ±0.06 c,d 0.33 ±0.03 a,b 0.171 ±0.003 d 0.252 ±0.012 b,c 0.41 ±0.03 a 20 0.13738 ± 0.00010 d 0.3217 ±0.0010 a 0.228 ±0.011 c 0.256 ±0.018 b 0.2160 ±0.0004 c 21 0.33189 ±0.00505 a 0.19194 ± 0.00964 b 0.1107 ±0.00355 d 0.12197 ±0.00687 d 0.14953 ±0.00067 c Lactones γ-Butyrolactone A 19 0.032 ±0.005 b,c 0.0410 ±0.0017 c 0.0142 ±0.0008 a 0.0310 ±0.0008 b 0.030 ±0.003 b 20 0.0089 ±0.0004 a 0.0164 ±0.0011 c,d 0.0100 ±0.0014 a,b 0.0136 ±0.0013 b,c 0.020 ±0.003 d 21 0.0141 ±0.0004 c 0.0084 ±0.0011 a 0.007573 ± 0.000014 a 0.00852 ±0.00008 a, b 0.0102 ±0.0009 b 2,5-Dihydro-3,2-furanone C 19 0.00099 ± 0.00004 b – 0.000775 ± 0.000010 a 0.00102 ±0.00005 b 0.00079 ±0.00011 a 20 – 0.00153 ±0.00020 – – – 21 – – – – – 2(5H)-Furanone B 19 0.025 ±0.003 a 0.0490 ±0.0019 c 0.0238 ±0.0023 a 0.0398 ±0.0016 b 0.041 ±0.003 b 20 0.00726 ±0.00020 a 0.033 ±0.003 d 0.02173 ±0.00023 c 0.020 ±0.003 c 0.0112 ±0.0020 b 21 0.021 ±0.003 b 0.0112 ±0.0015 a 0.0077 ±0.0008 a 0.0109 ±0.0014 a 0.0108 ±0.0010 a Cyclotene A 19 0.0144 ±0.0018 b 0.0174 ±0.0009 c 0.0096 ±0.0006 a 0.01785 ±0.00016 c 0.0185 ±0.0004 c 20 0.0022 ±0.0008 a,b 0.0142 ±0.0006 b 0.00805 ±0.00010 a, b 0.0088 ±0.0010 a,b 0.0051 ±0.0003 a 21 0.0147 ±0.0022 c 0.0052 ±0.0008 b 0.00433 ±0.00004ª , b 0.00210 ±0.00008 a 0.00165 ±0.00016 a γ-Nonalactone A 19 0.0105 ±0.0017 b 0.0102 ±0.0005 b 0.0076 ±0.0003 a 0.0102 ±0.0007 b 0.0087 ±0.0009 a,b 20 0.00615 ±0.00006 a 0.0165 ±0.0006 c 0.0114 ±0.0008 b 0.0100 ±0.0011 b 0.018 ±0.003 c 21 0.00729 ±0.00020 c 0.00476 ± 0.00006 a,b 0.0042 ±0.0003 a 0.0039 ±0.0003 a 0.0054 ±0.0007 b γ-Decalactone A 19 0.002248 ± 0.000019 a 0.0036 ±0.0004 b 0.00185 ±0.00014 a 0.00212 ±0.00007 a 0.00213 ±0.00021 a 20 0.00190 ±0.00018 a 0.00226 ± 0.00020 b,c 0.002390 ± 0.000021 c 0.0026 ±0.0002 d 0.00215 ±0.00005 b 21 0.00198 ±0.00018 a 0.00275 ±0.00007 a 0.00215 ±0.00022 a 0.00182 ±0.00005 b 0.0033 ±0.0004 b Dihydroactinidiolide C 19 0.0040 ±0.0006 b 0.0030 ±0.0003 a 0.0026 ±0.0003 a 0.0044 ±0.0007 b 0.0061 ±0.0009 b 20 0.0029 ±0.0006 a 0.0066 ±0.0015 c 0.0042 ±0.0005 b 0.0047 ±0.0007 b 0.00607 ±0.00018 c 21 0.0034 ±0.0004 c 0.0032 ±0.0004 c 0.002156 ± 0.000013 a 0.00247 ±0.00006 a, b 0.00295 ±0.00022 b, c Total of lactones 19 0.089 ±0.010 c 0.1243 ±0.0011 a 0.0604 ±0.0010 d 0.1064 ±0.0006 b 0.107 ±0.008 b 20 0.036 ±0.008 c 0.091 ±0.006 a 0.0578 ±0.0008 b 0.060 ±0.006 b 0.062 ±0.008 b 21 0.062 ±0.005 a 0.0355 ±0.0024 b 0.0281 ±0.0010 c 0.0297 ±0.0015 b,c 0.0345 ±0.0011 b,c Methyl Esters Methyl octanoate B 19 – – – – – 20 – – – – – (continued on next page) E. Valero et al. Food Research International 160 (2022) 111694 16 2-furfuraldehyde, diacetyl, 6-Methyl-5-hepten-2-one, ɣ-nonalactone, hotrieno, nerol, vanillin among others. When volatile compounds data was grouped to obtain the hypothetical aroma profile of these musts, differences due to cover crop treatment that were again different in each harvest (Fig. 8) can also be observed. Hence, in the 2019 harvest (Fig. 8A) citric, nutty, fruit, spicytoasted and off-flavour aromatic notes were significantly higher in musts without cover crop, highlighting the cheese-pungent and dairy notes in musts from vines with the maximum number of lines around them (SE4Z). The musts obtained from vines cultivated without cover crop in the 2020 harvest accounted for the highest values for dairy and sweetcaramel-coffee aromatic notes, and when a large amount of cover crop was used around musts (SEZZ and SE4Z), the musts obtained presented the lowest values for balsamic-chemical, cheese-pungent, and nutty SELL19 SELZ19 SELL20 SELZ20 SE4Z20 SELL21 SELZ21 SEZZ21 SE4Z21 -15 -10 -5 0 5 10 15 Factor 1: 36,76% -10 -5 0 5 Factor 2: 22,42% SEZZ20 SE4Z19 SEZZ19 Fig. 4. PCA scores plot of musts from organic cultivation obtained in all three harvests studied. Fig. Z. SELL19-3 SELZ19-1 SEZZ19-2 SE4Z19-1 SE4Z19-2 SE4Z19-3 -20 -15 -10 -5 0 5 10 15 Factor 1: 46,42% -10 -5 0 5 10 Factor 2: 26,20% SELL19-1 SELL19-2 SELZ19-3 SELZ19-2 SEZZ19-1 SEZZ19-3 Fig. 5. PCA scores plot of musts from organic cultivation obtained in the 2019 harvest. E. Valero et al. Food Research International 160 (2022) 111694 17 notes (the first two could be considered as negative aromas). Moreover, in the case of SE4Z, the sweet-caramel-coffee and spicy-toasted aromas were also significantly lower than in the other musts (Fig. 8B). In the case of the 2021 harvest, a significant increase of balsamic-chemical aroma was observed as the amount of cover crop increased and a contrary trend showed the cheesy-pungent aroma, reaching the highest value in the case of absence of cover. Moreover, these kinds of musts can be highlighted for their citric, sweet-caramel-coffee, and fruit aromatic notes (Fig. 8C). If we compare the aromatic profile of musts obtained in the different harvests by subjecting vines to the same cover crop treatment (Fig. 7S. Supplementary material), very different aromatic profiles are observed, SELL20-2 SELL20-3 SELZ20-2 SEZZ20-1 SE4Z20-2 SE4Z20-3 -10 -5 0 5 Factor 1: 39,23% -10 -5 0 5 10 Factor 2: 27,82% SELZ20-3 SELZ20-1 SE4Z20-1 SELL20-1 SEZZ20-2 SEZZ20-3 Fig. 6. PCA scores plot of musts from organic cultivation obtained in the 2020 harvest. SELL21-2 SELL21-3 SELL21-1 SELZ21-3 SELZ21-1 SEZZ21-1 SE4Z21-1 -10 -5 0 5 10 Factor 1: 38,87% -10 -8 -6 -4 -2 0 2 4 6 8 10 Factor 2: 31,85% SELZ21-2 SE4Z21-3 SE4Z21-2 SEZZ21-2 SEZZ21-3 Fig. 7. PCA scores plot of musts from organic cultivation obtained in the 2021 harvest. E. Valero et al. Food Research International 160 (2022) 111694 18 Fig. 8. Spider Chart of hypothetical aromatic profile of musts from cultures with different cover crop treatments: (A) 2019 harvest, (B) 2020 harvest and (C) 2021 harvest. E. Valero et al. Food Research International 160 (2022) 111694 19 especially in the case of musts from vines cultivated with one line of Zulla around them (SELZ). Conversely, the most similar musts seem to be those from vines cultivated with the highest amount of Zulla around them, from the 2020 and 2021 harvests. These also showed the lowest values for most aromatic notes. On the other hand, there are several volatile sulphur compounds associated with typical ‘reduced’ aromas in wine, such as methanethiol and ethanethiol. Shiraz wines can present this aromatic defect. Bekker, Wilkes, and Smith (2018) showed dimethyl disulphide and methyl thioacetate were important precursors to methanethiol. Dimethyl disulphide was detected in the musts studied except in must from vines cultivated with the highest amount of Zulla cover crop, in the last two harvests. Moreover, an inverse correlation between the amount of this compound and the proportion of Zulla cover crop around the musts was noted. This could indicate that there is a positive effect of Zulla cover crop with regard to this wine off-flavour. The results showed important differences in volatile and aromatic profiles of the studied musts from the different harvests, highlighting the significant influence exerted by climatic conditions on the composition of secondary grape metabolites. However, the mean temperatures of the three harvests were quite similar and the main difference was the rainfall, being more abundant in 2020 and 2021. as well as showing a different annual rainfall pattern (Fig. 1S. Supplementary material). Thus, the rainiest months were October and November for the 2019 harvest, January and March for the 2020 harvest, and November and January for the 2021 harvest. Although there seems to be a detriment in the content of volatile compounds due to cover crop in the first harvest, this was gradually lessened in each harvest. Hence, the cover crop may exert a certain negative effect on volatile composition during the first years of implantations due to a possible competition for nutrients or water with the vine, but as time goes on, this negative influence seems to begin to disappear, thanks to the advantages provided by cover crops, as opposed to soil tillage. 4. Conclusions The influence of different kinds of vineyard cultivation managements on the volatile profile of musts was studied. The results showed that the effect of the harvest on must volatile composition is more important than agronomic practices during the three years studied. Zulla cover crop did not produce negative effects on volatile profile with respect to conventional or organic cultivation with soil tillage. Therefore, organic cultivation using Zulla cover crop, during the months before the sprouting of the vine, is a suitable tool for the implementation of friendly ecosystem management in a warm climate Syrah vineyard. Further studies to assess the longer-term effect could be performed. CRediT authorship contribution statement E. Valero: Conceptualization, Methodology, Investigation, Writing – original draft, Supervision, Project administration, Funding acquisition. F. Arranz: Investigation, Formal analysis, Writing – original draft. B.J. Moy´ a: Investigation, Formal analysis, Writing – original draft. S. Cruz: Investigation, Writing – review & editing. B. Puertas: Conceptualization, Methodology, Resources, Writing – review & editing, Project administration, Funding acquisition. M.L. Morales: Methodology, Formal analysis, Resources, Writing – original draft, Writing – review & editing, Visualization, Supervision, Funding acquisition. Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Acknowledgments This research was funded by the Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA) through the Project “Investigaci´ on e Innovaci´ on Tecnol´ ogica en Vitivinicultura” (PR.AVA. AVA2019.016) and the European Rural Development Fund (ERDF, EU); and by the European Regional Development Fund (FEDER) and by the Consejería de Economía, Conocimiento, Empresas y Universidad, of Junta de Andalucía, within the framework of the Andalusian FEDER operational program 2014-2020. Specific objective 1.2.3. «Promotion and generation of frontier knowledge and knowledge lead to the challenges of society, development of emerging technologies» within the framework of the reference research project (FEDER-UPO 1381315). FEDER co-financing percentage 80%. Authors would also like to thank the financial aid from the VI Own Research and Transfer Plan of the University of Seville. Appendix A. Supplementary material Supplementary data to this article can be found online at https://doi. org/10.1016/j.foodres.2022.111694. References Abad, J. H., de Mendoza, I., Marín, D., Orcaray, L., & Gonzaga Santesteban, L. (2021). Cover crops in viticulture. 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