To investigate the effects of the application of bentonite, tannins, and their combination in alcoholic fermentation, Malvazija istarska (Vitis vinifera L.) white grape must was treated with 95 g/L ...of bentonite, 25 g/L of a hydrolysable tannin preparation, while the third treatment received the aforementioned doses of both agents. Control grape must was fermented without bentonite and exogenous tannins. All of the produced wines were additionally fined after fermentation with doses of bentonite needed to achieve complete protein stability. Wines were analyzed both after fermentation and after additional bentonite fining. Standard physicochemical parameters were determined by the OIV methods, and phenols were analyzed by high-performance liquid chromatography with diode-array detection (HPLC-DAD), while the concentrations of free and bound volatile aroma compounds were obtained after solid-phase extraction (SPE) followed by gas chromatography–mass spectrometry (GC-MS). Bentonite and tannins in fermentation generally reduced the total dose of bentonite needed for complete stabilization. Treatments with bentonite slightly decreased the concentration of total dry extract, while tannins preserved total acidity. The negative effect of bentonite on flavonoids was more severe. Tannins in fermentation preserved more hydroxycinnamoyltartaric acids with respect to control wine, and this effect was additionally enhanced by bentonite. Volatile and bound aroma composition was affected by all the treatments, while the addition of tannins resulted in higher concentrations of several important odoriferous esters, such as ethyl hexanoate, ethyl decanoate, and hexyl acetate. Additional fining with bentonite to complete protein stabilization annulled some of the positive effects observed after fermentation.
The aim of this study was to investigate the impact of early leaf removal (ELR) and cluster thinning (CT) on the phenolic composition of cv. Teran berries and wines, and the sensory profile of wines ...at 6 and 24 months after fermentation. Although only ELR increased the concentration of total anthocyanins in the berries as compared to the untreated control (UC), both ELR and CT had higher concentration of total anthocyanins and greater colour intensity in the resultant wines than the UC. Similar effects were obtained with total phenolics in the berries and the wines; while CT obtained higher concentration of total phenolics in the berries than UC only in one season, same treatment obtained higher concentration of total phenolics in the wine in both seasons as compared to UC. Only minor sensory differences in wines were obtained at the age of 6 months, while treatments were highly discriminated 24 months after fermentation, when both ELR and CT wines had more enhanced fruitiness, aromatic intensity, complexity, body, balance and wine overall quality than UC. The obtained results indicate that adequate wine aging period is needed for a relevant assessment of the impact of vineyard management practices on wine sensory characteristics.
The majority of chemical compounds that contribute to varietal aroma originate from grape skin. To investigate the differences between volatile aroma compounds when different maceration conditions ...are applied, a total of six vinification treatments were carried out on Malvazija istarska (Vitis vinifera L.) variety, non-maceration control treatment (C), pre-fermentative two days cryomaceration treatment at 8 °C (CRYO), seven days maceration treatment at 16 °C (M7), 14 days maceration treatment at 16 °C (M14), and prolonged post-fermentative maceration treatments at 16 °C for 21 day (M21) and 42 days (M42). Wines were subjected to GC/MS and sensory analysis. Obtained results showed that prolonged post-fermentative maceration treatments contained the highest concentration of total volatile aroma compounds, precisely monoterpenes, alcohols, and other esters. Contrary, C and CRYO wines resulted in highest concentration of ethyl and acetate esters, and fatty acids. In addition, sensory analysis showed that longer maceration treatment wines (M14, M21, M42) were characterized by more aroma complexity, varietal flowery typicity, pronounced fruitiness, with accentuated dried fruit, moderate honey, and herbal notes. Obtained results can provide valuable information to producers when choosing an appropriate vinification technique based on the desired wine style which may lead to a further diversification of white wine market.
Sauerkraut is produced by cabbage fermentation either spontaneously or by adding lactic acid bacteria. Although commercial cabbage cultivars are more desirable due to their higher yield and ...uniformity, traditional cultivars are highly prized for their unique sensory characteristics and suitability for fermentation. The aim of this study was to investigate the properties of sauerkrauts from traditional cabbage cultivars ('Brgujski' and 'Žminjski') compared to commercial samples, and to unravel the effects of ambient (18 °C) and cold storage (4 °C) on sauerkraut properties. Higher total phenolic contents and total antioxidant capacities measured by both FRAP and DPPH methods were observed for sauerkrauts from traditional cultivars. In total, 32 volatile compounds were identified, and differences in the volatile profile were observed among the investigated sauerkrauts. The sensory properties of traditional cabbage cultivars were on par, or even better, compared to those of commercially available sauerkraut products. The cold storage conditions characteristic of commercial environments preserved the total antioxidant capacity, the red to green color ratio (
), as well as the lightness (
) of sauerkraut compared to the ambient temperatures characteristic of domestic conditions, indicating the preservation of bioactive compounds responsible for the purple cabbage head coloration of the investigated traditional cultivars.
The purpose of the survey was to identify and analyze moderate wine consumption of Croatian autochthonous wine varieties. The survey was conducted in 2019 and 2020 on the Croatian Science Foundation ...scientific project “Vinum Sanum”. Dimensions of wine and health benefits, wine quality, labelling, positive and negative effects on wine labels and psychological well-being were assessed with a questionnaire from 374 participants. Results indicated that wine was perceived as a healthy beverage, consumed as part of healthy life style. Health benefits were perceived positively through cardiac, physical health and psychological well-being. Most important quality features were: origin; micro region, terroir, PGI/PDO (protected geographic origin/protected designation of origin), vintage, ageing and sugar content. This survey might be used as scientific evidence for developing health claims for wine, for producers to use health enhancing properties of wines and create packages and/or labels which may boost the positive perception of wine health benefits.
Viticulture production is challenged by climate change and the consequent higher accumulation of carbohydrates in grapevine berries, resulting in high-alcoholic wines. This study investigates the ...application of severe shoot trimming performed at three different stages and crop size management as tools for the modulation of cv. Merlot berry composition, aimed at reducing the sugar content in the berry. In the first study, the effects of severe shoot trimming carried out at three different phenological stages were studied. In the second study, late severe shoot trimming was combined with two crop sizes and regulated by shoot thinning. The obtained results demonstrated that severe shoot trimming in earlier stages of berry development limited the accumulation of both sugars and anthocyanins as compared to the control treatment. However, when severe shoot trimming was performed at late veraison (at approximately 14 Brix), it decreased only the accumulation of sugars, without affecting the accumulation of anthocyanins. The results of the second study showed that the modification of crop size by shoot thinning significantly affected the measured yield parameters, whereas the effect on Brix and anthocyanins was seasonally dependent. It was concluded that among the studied techniques, severe shoot trimming at late veraison is the most effective way to reduce sugar content in the berry without affecting the accumulation of anthocyanins.
Pesticide residues and heavy metal concentrations were determined in two depths (0–20 and 20–40 cm) of Chromic Cambisol in 69 vineyards in the Slovenian winegrowing region of the Karst. Similarly, ...pesticide residues and heavy metal concentrations were also determined in two depths of Calcaric Cambisol in 11 vineyards in the other Slovenian and Croatian winegrowing regions of Istria. The topsoil (0–20 cm) was analysed for the presence of 176 different pesticidal active substances using two multiresidue analytical methods: (a) gas chromatography coupled with mass spectrometry (GC/MS) and (b) liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). Seven active substances (five fungicides and two insecticides) were detected in the soil samples. Their concentrations were compared with the maximum concentrations observed in the vineyards of the winegrowing regions of France, Italy, and Spain. In addition to pesticides, the soil samples were analysed for the presence of nine heavy metals commonly detected in vineyard soils. The concentrations of arsenic, cadmium, cobalt, chromium, copper, molybdenum, nickel, lead, and zinc were below the critical thresholds set by Slovenian legislation, with the exception of one soil sample in which the Cu concentration exceeded the critical threshold. Compared with the maximum concentrations measured in other vineyard soils in Spain, Italy, and France, the heavy metal concentrations in the vineyard soils of Karst and Istria were lower. Both the heavy metal concentrations and the residual concentrations of pesticidal active substances in the vineyard soils of the Karst and Istria regions were significantly lower than the concentrations that are occasionally discussed in the literature.
Biska, a traditional Istrian herbal spirit, is produced by macerating mistletoe leaves and twigs in a water–ethanol base, usually grape marc spirit. The aim of this study was to determine the optimal ...mistletoe maceration parameters (ethanol content, concentration of plant material, and duration) for the production of biska, which have not yet been the subject of scientific research. The prepared mistletoe macerates and the collected biska samples were subjected to phenolic compound characterization, including total phenolic content (TPC), total flavonoid content (TFC), and polyphenolic profile, by ultra-high-performance liquid chromatography coupled with mass spectrometry (UPLC-ESI-MS2). In addition, the macerates and the biska samples were analyzed for their biological properties: antioxidant and antiproliferative activity. The results showed that both the macerates and the biska samples contain phenolic compounds of mistletoe such as phenolic acids, flavonoids, and coumarins, which contribute to the observed biological activities—significant antioxidant activity and antiproliferative effect. By applying the maceration parameters, which yielded the highest content of phenolic compounds as well as volatile aromatic compounds (40–80 g/L of mistletoe, 40–55% v/v ethanol, and 21 days’ maceration time), the production process can be improved to produce biska with better aromatic and biological properties.
This study aimed to evaluate the effects of cluster thinning and severe shoot trimming on berry and wine composition and wine sensory characteristics of Merlot variety, in the context of climate ...change challenges related to grapevine ripening and the corresponding high alcohol content in wine. In two seasons, two different crop sizes were obtained via cluster thinning and combined in a two-factorial design with severe shoot trimming (SST) and its respective high canopy control (HC). In both seasons, cluster thinning (CT) resulted in higher Brix in grape juice and higher alcohol in wine than full crop size (FC), whereas SST obtained lower values than HC. Total anthocyanins and phenolics in wine were increased by CT, whereas SST had no any significant effect on wine’s phenolic content. Several sensory characteristics of wine were positively affected by CT in both seasons, including aroma intensity, wine body and overall wine quality, whereas SST wines were in one season characterized by increased perception of vegetal aroma, acidity and bitterness, and decreased perception of body, persistency and taste balance. Our results demonstrate that practices which affect the leaf area to fruit ratio have a major impact on wine sensorial characteristics, concluding that their choice should be based on the desired wine style.
Moderate wine consumption is often associated with healthy lifestyle habits. The role of wine as a healthy drink is mainly due to its bioactive compounds, which differ according to various ...viticultural and enological factors. The aim of the present study was to observe the differences in bioactive compounds of white and red autochthonous Croatian wines, differing in terms of the grape variety and production technology. Our further aim was to explore the effect of their moderate consumption (200 mL per day) over the course of six weeks on some aspects of health in sixty-six healthy individuals. Participants were divided into eight groups depending on the wines consumed, while one group formed a non-consuming control group. Medical examination and laboratory tests were performed before the start and at the end of the consumption period. Systolic and diastolic blood pressure, total cholesterol, and LDL concentrations decreased. Additionally, an increase in HDL concentrations, and serotonin and dopamine levels, was observed. ALT, ALP, and GGT levels did not significantly increase in consumer groups, although alcohol concentration was relatively high in all the wines. Such results support the beneficial effects of wine-derived bioactive compounds on some health aspects resulting from moderate white and red wine consumption.
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