Search Results (41)

The grapevine syndrome, Esca proper, causes significant yield losses. This study analyses and discusses the enological traits of musts from healthy (HV) and Esca-proper-affected (EpV) ‘Primitivo’ vines cropped in southern Italy. Tiger-striped leaves, sudden wilting on arms or shoots, berry spots, shrivelling and wilting, wood browning and white rot are linked to the presence of Phaeoacremonium minimum, Phaeomoniella chlamydospora, and Fomitiporia mediterranea within the woody tissues and characterize EpVs. The lack of symptoms on trunks, leaves, berries, and in the wood of branches and shoots, along with the absence of Esca-proper mycota, typifies HVs. Must from the selected HVs is darker and contains greater total soluble solids, reducing sugars, titratable and volatile acidity, tartaric, citric, and L-malic acid, and total polyphenols. The must from the selected EpVs has a higher pH and laccase activity, and contains pullulan, scytalone, and isosclerone, secondary metabolites of P. minimum and P. chlamydospora. During fermentation, musts from EpVs negatively impact the growth and enological performance of Saccharomyces cerevisiae Byosal HS1™ and IOC 18-2007™ and reduce the overall quality of the resulting wines. The physical–chemical conditions during fermentation may degrade pullulan and aid scytalone oxidation to isosclerone. Full article

Developing an environmentally friendly material with dual functionality of corrosion monitoring and inhibition is crucial for reducing economic losses. Herein, dual-function phytic acid carbon dots (PA-CDs) were prepared with a hydrothermal treatment method for corrosion monitoring and inhibition. The as-prepared PA-CDs exhibited a distinct color change from brown-yellow to wine-red immediately in the presence of OH⁻, and H⁺ can restore the color of the PA-CDs-OH⁻ system from wine-red to brown-yellow. Inspired by the above phenomenon, a visible RGB-based colorimetric sensor was fabricated by combining PA-CDs coatings with the self-made RGB-sensing device to detect OH⁻/H⁺ during metal corrosion. In addition, PA-CDs had excellent corrosion inhibitory properties for Q235 steel hanging sheets in hydrochloric acid solutions, and the corrosion inhibition efficiency reached 96.40%. The excellent corrosion monitoring and inhibition properties demonstrate the potential application of the PA-CDs in engineering practice. Full article

The increasing interest in valorizing agricultural by-products has positioned grape pomace as a rich source of bioactive compounds. This study developed an effect-directed extraction (EDE) approach guided by bioactivity quantification on thin layer chromatography (TLC). Twelve grape pomaces were screened based on antioxidant and tyrosinase inhibitory properties. Using hydroalcoholic solvent (ethanol:water, 1:1), the two most promising sources (Malbec from San Rafael) were subjected to response surface methodology (RSM) to optimize extraction of anti-browning and antioxidant compounds visualized as TLC spots. Temperature and time were optimized (76 °C, 45 min), and samples were analyzed using TLC coupled with DPPH and laccase inhibition bioautography. Antioxidant compounds showed retention factor values on TLC plates of 0.37 and 0.75 (DPPH/ABTS-active), while laccase inhibition occurred at Rf 0.35, coinciding with the primary tyrosinase inhibition zone. However, subsequent bioassay-guided HPLC fractionation and HRMS/MS analysis revealed that tyrosinase and laccase inhibitions are mediated by distinct compounds within this bioactive zone, highlighting a synergistic multi-target effect in the optimized extract that is retained throughout the process. The primary tyrosinase inhibitor at Rf ~0.35 was tentatively elucidated as an acylated anthocyanin, consistent with malvidin-3-O-(p-coumaroyl)glucoside. Optimized extracts were evaluated on Pink Lady apple slices at different timepoints. The browning index was reduced by 25% versus the control at 15 h, confirmed by significantly lower ΔE values (p < 0.05). The process requires only food-grade solvents and conventional equipment, facilitating scale-up for grape pomace generated worldwide. Validating the EDE strategy, this TLC-guided approach successfully tracked and preserved the primary anti-tyrosinase activity from the crude waste matrix down to the tentatively identified molecule, contributing to circular economy objectives in the wine industry. Full article

Winemakers have to deal with enzymatic browning caused by a grape polyphenol oxidase called tyrosinase. Due to the problems related to sulphur dioxide and its use in winemaking, oenologists need alternative and effective treatments for inhibiting enzymatic browning. This research studies ascorbic acid, glutathione (pure and in the form of a specific inactivated dry yeast rich in glutathione), and bioprotection by a selected strain of Metschnikowia pulcherrima as alternatives to SO₂ for preventing enzymatic browning, following a methodology developed in previous works. All the studied treatments resulted in a significant reduction in enzymatic browning. More specifically, all treatments significantly reduced the Vmax of the apparent tyrosinase activity, indicating their potential to protect against enzymatic browning and thus allowing for a reduction in the doses of SO₂ added to the wine. Full article

This study investigates the effects of terroir on the sensory expression of two major white grape varieties, Fetească albă and Sauvignon blanc. The experimental design included wines from eleven wineries distributed across the main Romanian wine-growing regions—Banat, Dobrogea, Moldova, Muntenia–Oltenia, and Transylvania—covering a wide range of altitudes (75–400 m), latitudes (21.6–28.4°), and contrasting soil types (chernozems, alluvial soils, luvaceous and clay-illuvial brown soils) over two climatically distinct vintages (2019 and 2021). Volatile profiling was performed by GC–MS, and aroma relevance was assessed using odor activity values (OAVs) and weighted aromatic scores, while sensory attributes were integrated through structured sensory evaluation. Esters and thiols emerged as the dominant contributors to varietal aroma expression. Sensory aggregation revealed clear winery-dependent differences, whereas vintage effects were moderate, with 2021 wines displaying a more pronounced fruity–floral profile compared to 2019. Linear Discriminant Analysis (LDA) identified grape variety as the strongest discriminant factor, surpassing vintage, and confirmed distinct regional sensory identities. The integrated OAV–sensory–LDA framework demonstrates the defining role of terroir in shaping aromatic structure, enabling robust varietal typicity assessment and regional differentiation across Romanian wine-growing areas. Full article

This study aimed to improve the quality of sweet rice wine through exogenous addition of rice bran and extrusion. The effects of directly fermenting brown rice and adding rice bran on key quality indicators including alcohol content, sugar-to-acid ratio, antioxidant properties, and sensory characteristics were evaluated. Compared to direct fermentation, the exogenous addition of rice bran significantly improved overall wine quality, with 4% rice bran yielding the optimal alcohol content of 1.6% vol and sugar-to-acid ratio exceeding 40. Extrusion modified the physical structure of rice bran, improving its performance as a fermentation substrate. Consequently, both the antioxidant activity and flavor profile of the sweet rice wine were further enhanced. These findings provide valuable theoretical insights for the development of high-quality whole-grain foods. Full article

Obesity, a prevalent global health issue, arises from an imbalance between caloric intake and energy expenditure, leading to the expansion of adipose tissue and metabolic dysfunction. White adipose tissue (WAT) stores energy as lipids, while brown adipose tissue (BAT) plays a pivotal role in energy dissipation through adaptive thermogenesis. Recent research initiatives have focused on finding strategies to decrease adipogenesis and fat mass accumulation and increase thermogenesis. Finding chemicals with anti-obesity properties would be beneficial. Resveratrol, a polyphenolic compound abundantly found in the skin of grapes and red wine, possesses anti-oxidant, anti-inflammatory, anti-cancer, and anti-obesity properties. This literature review examines the effects of resveratrol on adipocytes in culture and adipose tissue in animal models of obesity. The existing evidence indicates that resveratrol may exert its anti-obesity effects by inhibiting adipogenesis, promoting the apoptosis of mature adipocytes, reducing lipid accumulation, and increasing thermogenesis. Further research utilizing animal and clinical studies is required to understand in detail the anti-obesity potential of resveratrol. Full article

The aging ability of dry white wines has been increasingly recognized. The present work aimed to identify which sensory features drive their quality assessment by experienced tasters. Individuals assessed several sensory attributes, using dark tasting glasses. Wines originated from the grape varieties Alvarinho, Arinto, Sauvignon Blanc and Pinot Bianco with a wide range of ages. Basic physical–chemical analysis, browning (Abs 420 nm), elemental composition and a partial volatile fraction were also determined. The overall quality scores were a function of complexity and balance and were negatively influenced by the perception of faultiness. The aging process could be associated with a continuous sensory space characterized by a declining perception of freshness and an intensification in the mellowed flavors. Despite their age, wines were characterized by an austere perception caused by their acidity, saltiness, bitterness, smoothness and dryness. Nevertheless, quality scores were similar from the youngest to the oldest tasted wines (17 years old). The exception was a Sauvignon Blanc wine from a recent vintage that was judged as faulty due to the perception of earthiness. Overall, the tasted wines displayed an unexpected aging ability as demonstrated by the difference between the predicted and real wine ages. To improve the recognition of old wines, the metaphor “mellowed by age” is proposed to describe flavors resulting from beneficial aging instead of “oxidized by age”. Full article

While a recent characterization of non-Saccharomyces thermally inactivated yeasts (TIYs) in a wine-like solution highlighted the release of oenologically relevant compounds and different oxygen consumption rates and antioxidant activity, here the impact of TIYs derived from Saccharomycodes ludwigii (SL), Metschnikowia pulcherrima (MP), Torulaspora delbrueckii (TD), and Saccharomyces cerevisiae (SC), as the reference strain, was evaluated in white wine. Wine treatment with TIYs resulted in an increase in polysaccharide concentration compared to the untreated wine, with SL-TIY exhibiting the highest release. Additionally, all TIYs, particularly SL-TIY, improved protein stability by reducing heat-induced haze formation. The addition of TIYs also demonstrated an effect on color parameters through phenolic compound adsorption, preventing potential browning phenomena. All TIYs significantly impacted the wine’s volatile profile. Overall, it was shown that an improvement in wine quality and stability may be obtained by using TIYs in the winemaking process. Full article

Chicken breasts and burgers (88% breast and 12% backfat) were evaluated for physicochemical characteristics, thiobarbituric acid reactive substances (TBARS), and antioxidant capacity during storage in vacuum or atmosphere conditions for 18 days at 4 °C using the following two formulations: one without incorporating white pomace seasoning (WPS) and another with 3% WPS. The WPS was obtained from white grape skins, a byproduct resulting from the elaboration of white wine. The addition of the WSP decreased the L* values and increased the a* values, resulting in a significant turning toward brown tones in the chicken products. The addition of 3% of WSP led to higher values of ABTS and FRAP, regardless of the type of packaging. Both types of packaging significantly increased the levels of TBARS, although vacuum packaging proved more effective in protecting against lipid oxidation compared to modified atmosphere package (MAP). Additionally, the WSP improved the oxidative stability regarding the TBARS values. In conclusion, the WSP could be a viable alternative to chemical antioxidants and would lead to healthier and innovative chicken products. Full article

The popular appreciation of dry white wines is most frequently directed to young wines. However, present consumption trends comprise the valorisation of aged dry white wines. Therefore, the present work was aimed at the sensory analysis of aged dry white wines to define their sensory space and to understand which factors drive their quality evaluation by experienced tasters (critics, oenologists and students). Individuals were asked to evaluate several synthetic and aesthetic attributes and to characterise the analytic sensory profile through a Check-All-That-Apply (CATA) methodology. The quality evaluations were differently correlated with wine synthetic parameters according to the taster group. For both critics and oenologists, overall quality scores were driven by persistence and complexity. Moreover, quality was also highly correlated with power for critics and with balance for oenologists. Quality scores were highly correlated with wine browning (absorbance at 420 nm) for critics. The tasting panel showed a homogeneous analytic description of aroma, taste and mouthfeel consistent with wine age. The different ages could be associated with a continuous sensory space characterised by a decreasing perception of freshness and an increase in mature and mellowed descriptors. All wines shared an austere in-mouth perception elicited by their acidity, saltiness, bitterness, smoothness and dryness. The age prediction showed that most tasters failed to guess the aged wines that were more than roughly 13 years old, indicating that tasters were not familiar with the sensory features of white wines from 17 to 46 years old. In conclusion, experienced tasters consistently described the sensory space and recognised the high quality of aged dry white wines. Education programs may use the defined sensory spaces according to aging and to expand the range of quality perception by consumers. Full article

The present study explores the efficiency of selenomethionine (Semeth), an organic form of Se, as an antioxidant compared with commonly used antioxidants (ascorbic acid, glutathione, and potassium metabisulfite) in preventing oxidative browning in Greek white wines (Malagouzia and Retsina). The experimental procedure involved an accelerated browning test conducted over 12 days at 55 °C, measurement of antioxidant activity values (using the Folin—Ciocalteau and the free radical diphenylpicrylhydrazyl (DPPH) methods), determination of free sulfhydryl groups using the Ellman’s method, and High-Performance Liquid Chromatographic analysis of selected phenolic compounds. Semeth consistently exhibited a preserving effect on total and free SO₂ content and antioxidant activity values of Malagouzia wines. Semeth also showed a protecting effect on free sulfhydryl groups (-SH), even higher than that of SO₂ suggesting that its role in maintaining wine color involves more mechanisms than just the prevention of SO₂ reduction. Moreover, Semeth demonstrated promising effects in preserving individual phenolic content, in particular (+)-catechin and fertaric acid, compared to the other antioxidant additions. Both browning rate constants and percentage color change values of Retsina where higher than the corresponding values of Malagouzia wines indicating greater susceptibility to browning. Browning development was dependent on the particular antioxidant added, with ascorbic acid being the least effective. The results of this study suggest that Semeth could be an important candidate for enhancing the oxidative stability of white wines, offering at the same time valuable information for optimizing antioxidant strategies in winemaking practices. Full article

Low fermentation temperatures are usually employed to obtain high-quality wines. This is especially interesting for white wine production since it prevents the loss of volatile compounds and a browning appearance; however, available fermentative yeasts do not usually tolerate low temperatures. Therefore, an interesting place to find new yeasts with cryotolerance is the Antarctic continent. From soil samples collected in Antarctica, 125 yeasts were isolated, of which 25 exhibited fermentative activity at 10 °C. After a fingerprinting assay, we classified the candidates into nine isotypes and sequenced internal transcribed spacer regions for their identification. These yeasts were identified as part of the Mrakia genus. Sugar and alcohol tolerance tests showed that some of these Antarctic soil yeasts were able to grow up to 9% alcohol, and 25% sugar was reached; however, they exhibited longer latency periods compared to the control Saccharomyces cerevisiae. The optimal growing temperature for the isolated Antarctic yeasts was between 10 °C and 15 °C. A comprehensive analysis of the results obtained showed that the isolates 10M3-1, 4M3-6, and 4B1-35 could be good candidates for fermentation purposes due to their alcohol, sugar tolerance, and growth features. Our results prove that it is possible to isolate fermentative yeasts from Antarctic soil with promising characteristics for their potential use in the wine production industry. Full article

The oxidation of wine may be beneficial or harmful to its quality. On the one hand, controlled oxidation can lead to the development of desirable sensory characteristics for red wine, such as enhanced color stability. Alternatively, oxidation can lead to white wine browning and a decrease in fruity aromas, and the development of an off flavor and wine polyphenols are also involved. The presence of glutathione (GSH) can help mitigate the negative effects of oxidation by acting as a protective antioxidant. In order to better understand the antioxidant role played by GSH, wine polyphenols oxidation experiments by electrochemical means in the presence of GSH were carried out. The oxidation behavior of polyphenols representing different phenolic classes commonly found in wines, including protocatechuic acid (PCA), caffeic acid (CAF), epicatechin (EC), and rutin (Ru), was investigated using cyclic voltammetry and bulk electrolysis. We identified the oxidation products and reaction pathways of these polyphenols using ultra-high-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), in both the absence and the presence of glutathione (GSH). UPLC-MS was utilized to demonstrate that, in the presence of glutathione (GSH), the four molecules were subjected to electrochemical oxidation, resulting in the formation of mono- and bi-glutathione conjugates. A two-electron oxidation process combined with the removal of two protons is the first step in transforming polyphenol molecules. As a result, the corresponding quinone is formed. The quinone can then be reduced back to its original form by glutathione (GSH), or it can interact further with GSH to produce mono- and bi-glutathione conjugates. These results contribute to understanding and predicting the oxidative degradation pathway of polyphenols in wine. Understanding this process seems important for winemakers to control and optimize the sensory characteristics of their wines. Full article

The application to agriculture of wheat-straw spent mushroom substrate amendments (compost/vermicompost) used to grow Pleurotus ostreatus has been analyzed. The study was conducted in a vineyard where the effect on (1) the physicochemical properties of the soil and the leaf and (2) the analytical characteristics and the aromatic composition of the wine were analyzed. The application of the amendments resulted in an increase in organic matter and macronutrients (NO₃⁻, P₂O₅ and K₂O) in the soil. With regard to the leaves, the NO₃⁻ and K₂O contents of those vines fertilized with vermicompost were higher, and the metallic content was the same regardless of the treatment applied. The analysis of the colorimetric parameters showed that there was a higher content of compounds with red and violet colorations in the case of wine obtained after treatment with vermicompost. In addition, for this type of wine, a higher concentration of volatile compounds was obtained. Thus, after grouping the aroma compounds into aroma series, the greatest differences among vermicompost wines and the rest were obtained in the fruit, floral, herbaceous, and green fruit series. The principal component analysis showed that the vermicompost treatment clearly differentiated the wine from the rest of the wines, in addition to its effects on the aromatic series, the values in the total polyphenol index, and the compounds responsible for brown tones. Full article