Nitrogen fertilizer efficiency in grapevine production is an important objective for solving the trade-off between improving yield and quality in agroecosystems and reducing environmental impacts. Influence of soil nitrogen fertilization and Fe foliar application on iron dynamics in soil and grapevine leaves of the ‘Graševina’ cultivar on carbonate soil was conducted in a two-year study in 2018 and 2019. The experiment was settled in three replicates on a total of seven fertilization treatments that differed in used form of nitrogen fertilizer and foliar application of Fe before and after the flowering of the grapevine: control (C); calcium ammonium nitrate (KAN); calcium ammonium nitrate + foliar Fe (KAN^+F); ammonium sulfate (AS); ammonium sulfate + foliar Fe (AS^+F); ammonium sulfonitrate + foliar Fe (ASN^+F); urea + foliar Fe (U^+F). Mineral fertilization with acid-forming nitrogen fertilizers (AS and ASN) significantly affected local acidification of alkaline soil, i.e., reducing the actual and exchangeable soil pH reaction, which resulted in increased soil Fe availability. Despite the increase in soil iron availability, no increased iron bioaccumulation in the grapevine leaves was found in the flowering and veraison stages at treatments where foliar fertilization was omitted. Of all the observed treatments, only foliar fertilization had a positive effect on iron concentration in the grapevine leaves, which leads to the conclusion that this is an effective way to solve iron deficiency symptoms and chlorosis occurrence. The use of mineral fertilizers with acid-forming nitrogen fertilizers for many years can result in a reduction of required foliar treatments and thus significantly affect the ecological and economic aspects of grape production. Thus, integrated iron management is needed to meet the needs of the grapevine for this micronutrient and to reduce the occurrence of leaf chlorosis in carbonate soil.

Grape-based brandies are one of the most popular alcoholic beverages in the world. The most popular one, Cognac, comes from the Charentes region of Southwest France, and it is mostly produced from the grape variety ‘Ugni Blanc’. However, wines destined for the elaboration of wine spirits also come from different white grape varieties; ‘Colombard’, ‘Folle Blanche’, ‘Montils’, and ‘Semillon’. In this study, the possibility of using the red grape varieties ‘Cabernet Sauvignon’ and ‘Syrah’ was investigated with an emphasis on the change of volatile compounds during the production process. During production, some specific volatile compounds such as 2-hexenal, 3-octanone, isopropyl myristate, ethyl palmitate, ethyl oleate, phenethyl acetate, 1-hexanol, and β-damascenone could be attributed to the primary aroma generated from the grape varieties. During the vinification and fermentation process, the development of ethyl hexanoate, ethyl octanoate, 3-methylbutanol, acetic acid, and octanoic acid occurred. Finally, 3-methylbutanol and predominant esters, ethyl hexanoate, ethyl octanoate, ethyl decanoate, and ethyl laurate, were generated during the distillation and maturation process. The composition and concentration of determined predominant esters in produced brandies suggest that both brandies have volatile profiles comparable to some of the world’s most popular brandies.

Vitis vinifera L. has been highlighted by its many positive effects on human health, including antibacterial, anti-inflammatory and antioxidant activity due to its rich phytochemical content. Removing six basal leaves has great potential to influence the production of phytochemicals. The purpose of this study was to determine the impact of different terms of defoliation on the antioxidant and antibacterial activity of grape skin extracts of the Blaufränkisch and Merlot varieties. The total phenolic concentration, total and individual anthocyanin concentration, antioxidant activity and antibacterial activity on gram-positive and gram-negative human pathogens have been determined. The study was conducted on three treatments (control treatment without defoliation, defoliation immediately after bloom and defoliation before the start of the véraison phase). The results showed statistically significant enhancement of the total phenolic concentration as well as the antioxidant and antibacterial activity in both studied cultivars. Defoliation just after blooming was the preferable defoliation term in the Merlot variety for achieving the highest total anthocyanin concentration, antioxidant activity and significant increase of antibacterial activity against all four investigated bacteria. Defoliation before the start of the véraison phase was the preferable defoliation term for achieving the highest total anthocyanin concentration in the Blaufränkisch variety. In general, treatment of defoliation immediately after bloom was more beneficial compared with the defoliation before the start of the véraison phase.

Stainless-steel tanks and wooden barrels are the most common wine ageing and storage vessels. Wooden barrels are often toasted to improve their chemical composition and influence on wine. The aim of this study was to investigate the changes in Merlot red wine aroma from the 2020 and 2021 vintages during 12-month storage (with sampling every 3 months) in a stainless-steel tank (SST), Excellence oak barrels with medium (EMT), medium plus (EMT+) and medium long (EMLT) toasting and a Premium oak barrel with medium toasting (PMT). The results showed that even slight differences in the time and temperature of medium toasting influenced the extraction of aroma compounds from wood to wine. The changes in individual aroma compounds depended on the vessel type, toasting level, initial wine composition and storage time. An increase in the total concentration of compounds with smoky, spicy and woody notes occurred in both wine vintages stored in wooden barrels, especially during longer storage. In samples from SST, floral, fruity and herbal aromas were more pronounced, according to the gas chromatography and sensory evaluators. Sensory evaluators rated the samples according to the 100-point test, and after 12 months of storage, 2020 and 2021 vintage Merlot stored in PMT obtained the highest points.

The aim of this study was to determine the effects of defoliation performed in the Babica red grape variety on the volatile compounds in produced wine. Three treatments were performed during 2017 and 2018: the removal of six leaves before flowering (FL) and at the end of veraison (VER), as well as control (C). Volatile compounds were analyzed using a gas chromatograph coupled to a mass spectrophotometric detector. Results were statistically evaluated by analysis of variance (ANOVA at the p = 0.05 level) and principal component analysis (PCA). Defoliation treatments were affected by the concentration of several compounds, but only in one year. The VER2017 treatment significantly increased the concentration of three aliphatic esters up to 8 C atoms and octanoic acid ethyl ester. The FL2017 treatment increased the concentration of three aliphatic alcohols. The FL2018 treatment has significantly enhanced the concentration ethyl cinnamate but decreased the concentrations of eugenol and dihydro-2-methyl-3(2H)-thiophenone. Both defoliation treatments reduced the concentration of γ-decanolactone in 2017. Aldehydes, monoterpenoles, and monoterpenes remained unaffected by the defoliation treatments. Vintage was found to be the largest source of variability for most volatile compounds under investigation, which was confirmed by PCA. The effect of defoliation in the mild-Mediterranean climate was found to mostly depend on seasonal weather conditions.