Antonio Amores-Arrocha

BACKGROUND: Organic viticulture is expanding across Mediterranean wine regions, driven by EU sustainability policies and increasing consumer demand. However, comparative studies assessing both physiological performance and productivity of grapevines under organic and conventional management while maintaining similar soil and climatic conditions remain limited, particularly in dry‐farmed warm Mediterranean environments. This study evaluated the physiological and agronomic responses of the grapevine cultivar ‘Pedro Ximénez’ over two consecutive seasons (2022–2023) in a commercial dry‐farmed vineyard in south‐western Spain managed under certified organic and conventional management systems. RESULTS: Leaf gas‐exchange parameters including net photosynthetic rate ( A _N ), stomatal conductance ( g _s ), intrinsic water‐use efficiency ( _i WUE), and the stomatal stress integral ( SI _gs ) were monitored alongside agronomic parameters such as bunch number, bunch weight, and pruning weight. Across both seasons, organically managed vines showed lower cumulative stomatal stress ( SI _gs reduced by 37% in 2022 and 14% in 2023) while maintaining similar seasonal iWUE values. During high vapor pressure deficit episodes, electron transport rate (ETR) remained comparable between management systems whereas A _N declined, indicating that photosynthetic reductions were mainly associated with CO₂ diffusional or biochemical limitations rather than photochemical impairment. Yield components were comparable between systems, although organic vines produced more clusters per plant in 2023 (17 ± 0.9 vs 15 ± 0.8; Tukey test, P < 0.05). CONCLUSION: Under the conditions of this commercial, warm Mediterranean vineyard, organic management was associated with reduced seasonal stomatal stress while maintaining comparable productivity, suggesting that organic viticulture may represent a viable strategy for dry‐farmed vineyards in warm Mediterranean regions. © 2026 Society of Chemical Industry.

Plant genetic resources are increasingly viewed as a key tool to address the multiple challenges faced by modern viticulture. In this context, local grape cultivars are proposed as a strategy to enhance resilience to climate change and to diversify wine styles. However, while genetic identification has been widely reported, field-based phenotyping information for local cultivars under current climate conditions remains limited. In this context, phenotyping results are presented for six local Andalusian cultivars (Castellano, Beba, Cañocazo, Mantúo de Pilas, Perruno and Vigiriega). All cultivars were grown in a vineyard plot in the Marco de Jerez and evaluated over three consecutive seasons (2023–2025). Morphology was assessed using 46 descriptors, allowing cultivars to be grouped into two main clusters. Phenological monitoring showed a measurable year effect while preserving a consistent relative ranking among cultivars, most clearly during veraison and ripening, with Castellano reaching these stages earlier and Mantúo de Pilas later. Grape must composition highlighted contrasting ripening dynamics, with Palomino Fino and Castellano generally reaching higher sugar levels, whereas Vigiriega and Mantúo de Pilas showed the most acidic profiles. These results provide growers with performance-based comparative information to support cultivar selection for new plantings and to explore the potential of local cultivars for developing new wine styles under warm climate conditions.

The consequences of climate change are prompting the development of strategies to adapt viticultural practices to increasingly warmer and drier climatic scenarios. In this context, grape sun-drying emerges as a potential resilience strategy for the production of overripe grapes for winemaking. This study focuses on comparing grape sun-drying practices carried out between vineyard rows as an alternative to the traditional technique ( asoleo ), evaluating the differences derived from location and drying surface. Over two vintages, grape clusters of Pedro Ximénez variety from both conventional and organic management managements were partially dried using two different surfaces: food-grade plastic and food-grade plastic mesh. The sun-drying process was monitored through weight loss, drying kinetics, and changes in grape musts physicochemical composition. Inter-row sun-drying reduced grape handling and eliminated the need for dedicated drying areas, while helping to preserve grape sanitary integrity. Food-grade plastic, due to its higher temperature retention, promoted greater water loss and higher sugar concentration. In contrast, the shading effect provided by the vine canopy in inter-row settings allowed for more balanced dehydration dynamics. Moreover, gluconic acid levels indicated that organic grapes preserved better sanitary integrity than conventional ones, suggesting that pre-harvest phytosanitary treatments may increase susceptibility to microbial development during sun-drying. The results support inter-row grape sun-drying as a practical and sustainable alternative to the traditional asoleo technique, particularly under warm climate conditions.

Grapevine (Vitis vinifera L.) is one of the most widely cultivated and economically valuable horticultural crops globally

BACKGROUND: In the present work, the content of volatile and phenolic compounds in sweet wines and mistelas made from sun‐dried Pedro Ximénez grapes, with and without skins during alcoholic fermentation, has been studied during their storage under oxidative conditions. Three possible significant factors have been considered: oxidative storage time, type of elaboration, and presence or absence of grape skins during alcoholic fermentation.RESULTS: The presence or absence of skins during alcoholic fermentation showed a low influence on the content of low molecular weight phenolic compounds and furfurals during the oxidative storage in stainless steel tanks. Storage time together with type of elaboration turned out to be the most influential factors, with decreases in phenolic compounds due to possible oxidative phenomena and increases in furfurals. The evolution of phenolic compounds during oxidative aging showed to be dependent on type of elaboration, with significant decreases at the beginning of storage for mistelas. In the case of volatile compounds, a high number of them showed significant differences in relation to the type of elaboration. The presence or absence of grape skins was, mainly, significant for ethyl esters, acids and alcohols, with higher relative extent in the absence of grape skins. For these compounds, the type of elaboration‐aging time interaction was also the most significant type, with significant decreases during the first 3 months of aging in mistelas.CONCLUSION: During the oxidative aging in stainless steel tanks, of sweet wines and mistelas elaborated with and without contact of grape skins during alcoholic fermentation, the main factor was oxidative aging time for phenolic and furanic compounds. Although, for volatile compounds, it was the type of elaboration, with mistelas showing a very different behavior to that of naturally sweet wines and natural sweet wines. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Searching for natural alternatives to synthetic fermentation activators has led to the study of bee pollen as a natural alcoholic fermentation activator. This study evaluated the potential of different bee pollen extracts (0.25 g/L) as activators in a Palomino Fino grape must. By analysing the composition of each extract, it was possible to identify the specific bee pollen fractions with the highest efficacy for activating alcoholic fermentation. Four extracts were obtained through sequential extraction using various organic solvents of increasing polarity (hexane, acetone, ethanol, and water), and their compositions were characterised. The effect of each extract was evaluated by monitoring the viable yeast populations and fermentation kinetics throughout the alcoholic fermentation process, along with the physicochemical and colour characterisation of the white wines obtained. The bee pollen fraction extracted with hexane, which was rich in long-chain fatty acids, significantly increased the maximum yeast populations and improved the fermentation kinetics. However, the extracts rich in polyphenolic compounds exhibited slower fermentation rates. Based on the obtained results, the lipid fraction of bee pollen extracted with hexane may be responsible for its ability to activate alcoholic fermentation.

Due to global warming and the effects associated with it, the wine industry is facing important challenges during the winemaking process and the production of high-quality wines. In this study, mistelas and naturally sweet wines were produced with the ‘Pedro Ximénez’ grapevine cultivar, overripened by sun drying and fermented with and without the presence of grape skins. Some oenological parameters related to alcoholic fermentation and low-molecular-weight polyphenols and furans were considered. Naturally sweet wines with skins presence showed a higher value of viable biomass than those with grape skins absence. However, in terms of density and ethanol production, sweet wines with grape skins absence presented lower and higher values, respectively, than the other elaborations. No significant differences in the organic acids and low-molecular-weight polyphenols and furans contents, with respect to the presence or absence of grape skins, were observed. In this sense, this research proves that the production of sweet wines from sun-dried grapes with the presence/absence of grape skins during alcoholic fermentation could be a possible choice in areas where agro-climatic conditions make it possible.

One of the challenges that European agriculture will have to face will be to adapt conventional agriculture to procedures of the new European agricultural policies. In this way, organic farming will have more importance in the coming years. One of the most important crops worldwide is grapevine. The main objective of this research work focuses on the physiological, agronomic, and enological characterization of Pedro Ximénez with the purpose of knowing the viability of the organic cultivation of this cultivar in a warm climate zone. Two experimental plots were selected with two different types of management, organic and conventional. In both plots, photosynthetic capacity (A_N), stomatal conductance (g_s), and intrinsic water-use efficiency (WUE_i) were measured, and physicochemical composition of grape must was analyzed during ripening. In addition, bunch and pruning weight were measured as agronomic parameters. Physiological results were not significantly different between management at a general level in g_s and WUE_i, being possible to identify a difference in A_N just before the harvest. At the level of fruit ripening, significant differences were found between the two managements. At harvest, grape must had a higher sugar concentration, amine nitrogen (α-NH₂), and yeast assimilable nitrogen (YAN) in the organic management than in conventional, where higher values of pH and l-malic acid were observed. Taking into account the preliminary results obtained it could be concluded the viability of the organic management for Pedro Ximénez crop in a warm climate zone.

In an enological market notable for its use of universal varieties, the enological potential of the somatic variant Tintilla de Rota has been studied in a warm climate area from where it originates and has been compared with three universal cultivars and with a reference cultivar in Spain. It has been found that Tintilla de Rota is a grapevine cultivar that can adapt easily to the area where it has been grown traditionally, achieving adequate pH and acidity values while maintaining a moderate sugar content compared to the other varieties studied. Additionally, it has shown high anthocyanin content. In terms of aromatic composition, it has exhibited a content equal to or even higher than the other varieties analyzed in this study in most of the aromatic families studied, with a higher content of compounds such as 1-octanol, benzyl alcohol and citronellol, which can lead to wines with an interesting and distinguished aromatic profile. All these facts confirm the interest in the use of this cultivar and the importance of recovering and enhancing the value of autochthonous cultivars as opposed to other so-called universal varieties.

Grape over-ripening is a technique that has historically been used for the production of white wines in southern Spain. However, this technique is still widely used for the production of sweet wines. In this study and after recently proving the feasibility of making dry white wines from overripe grapes with and without the presence of grape skin in a warm climate zone, the sensory characterization and analysis of the major and minor volatile compounds in dry white wines made from overripe grapes are presented for the first time. Two over-ripening techniques (sun-drying and climatic chamber drying) were studied for two different periods of time (48 and 96 h), as has the presence of grape skins during alcoholic fermentation. Grape over-ripening implies modifications in the composition of both the major and minor volatile compounds in wines. In terms of sensory analysis, wines with a similar profile were obtained year-on-year. The results of the preference test show that the wines made from grapes that had been over-ripened in the sun for 96 h were preferred by the tasting panel for both vintages. Thus, grape over-ripening under the sun could be considered as a resilience and adaptation technique for increased temperature conditions during the ripening season caused by the effects of climate change.