Search

Grape pomace is a major winery solid residue and several tons are annually produced worldwide. Since it is a valuable source of high value-added compounds, many strategies have been implemented for its valorization. The extraction of bioactive molecules with a broad range of applications is certainly the most investigated topics. In this context, oleanolic acid, a triterpenoid with a relevant biological activity, has been recently detected in grape pomace in remarkable quantities (0.45 mg per gram of fresh pomace). Herein, we report on a selective extraction of oleanolic acid from grape pomace by using dimethyl carbonate (DMC), a recommended green solvent as a better alternative to fossil-based solvents. Chemical–physical properties, Hildebrand's solubility and Kamlet–Abboud–Taft parameters have been considered to select a greener alternative to fossil-based solvents and theoretical calculations have been performed to determine the interaction between DMC and the oleanolic acid. The obtained grape pomace extracts were characterized by means of NMR and LC-MS. DMC allows the recovery of oleanolic acid from grape pomace, due to its weak polarity and poor ability to form H-bonds, with a molar selectivity of 61%, thus promoting the adoption of alternative green and sustainable technologies for biomass residue valorization. Also, DMC was recycled and reused in three consecutive extractions and no significant losses in terms of oleanolic acid extraction yield were detected. [ABSTRACT FROM AUTHOR]

Background: Climate changes have been leading to an excessive synthesis of quercetin (Q) and its glycosides (Q‐Gs) in specific red grape varieties, such as Sangiovese. This has resulted in concentrations overcoming the solubility threshold of Q in wines, with the consequent formation of undesirable precipitates. This study aims at assessing the impact of various factors, including anthocyanins, temperature, nucleation seeds and time, on the precipitation of Q in red wine. Results: The influence of anthocyanins on Q solubility was examined by adding a grape skin extract rich in anthocyanins to a model solution containing 89 μmol L−1 of Q. The data revealed that the solubility of both Q and Q‐Gs increased as a function of the anthocyanin concentration in the model solution. In a subsequent experiment, red wines were stored at two different temperatures (2 and 20 °C), supplemented with Q nucleation seeds, and monitored over a 10‐day period. Notably, after only 3 days of contact with Q seeds at 2 °C, a reduction of over 75% in Q concentration was observed in the supernatant. Among the considered factors, contact with nucleation seeds emerged as the most significant one (P < 0.0001). Conclusion: Q precipitation in red wines is influenced by the presence of anthocyanins in solution, although it is not the sole determinant. The data also suggested that a potential strategy for wineries to mitigate the risk of Q precipitation in bottled wine would be the acceleration of this process by promoting the formation of nucleation seeds. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability. [ABSTRACT FROM AUTHOR]

Climate change is causing a significant decrease in the total acidity of grapes and related wines. This represents a serious issue for sparkling wine production. Consequently, before the second fermentation, the acidification of base wines is often necessary. However, the impacts of the most important organic acids on the foam properties of sparkling wines are not yet well known. The impacts of the addition of tartaric, malic, citric, and lactic acid on the quality of Falanghina and Bombino sparkling wines were evaluated. Analyses were performed soon after the second fermentation and one year after aging sur lees. The addition of each different organic acid to the two base wines resulted in significant changes in the sparkling wines not only in terms of pH, titratable acidity, and buffering capacity but also in the content of total amino acids and, in some cases, in the height of the foam and its stability over time. For both grape varieties, acidified wines showed a lower content of total amino acids in comparison with the control wines. The addition of lactic acid determined a higher persistency of the foam even after one year of aging sur lees only in Falanghina wines. The results obtained herein highlight the importance of organic acids and the pH of the base wines for the content of amino acids in sparkling wines. No strict correlation between organic acid addition and the foamability of wines was observed. [ABSTRACT FROM AUTHOR]

The cultivated grapevine, Vitis vinifera subsp. vinifera, possesses a rich biodiversity with numerous varieties. Each variety adapts differently to varying pedoclimatic conditions, which greatly influence the terroir expression of wine regions. These conditions impact vine growth, physiology, and berry composition, ultimately shaping the unique characteristics and typicity of the wines produced. Nowadays, the potential of the different adaptation capacities of grape varieties has not yet been thoroughly investigated. We addressed this issue by studying two grape varieties, Aglianico and Cabernet Sauvignon, in two different pedoclimatic conditions of Southern Italy. We evaluated and compared the effect of different pedoclimatic conditions on plant physiology, the microbial quality of grapes using Next-Generation Sequencing (NGS) technology, the expression trends of key genes in ripe berries and the concentration of phenolic compounds in grapes and wines by HPLC-MS, HPLC-DAD, NMR and spectrophotometric analyses. Metabolomic and microbiome data were integrated with quantitative gene expression analyses to examine varietal differences and plasticity of genes involved in important oenological pathways. The data collected showed that the phenotypic response of studied grapes in terms of vigor, production, and fruit quality is strongly influenced by the pedoclimatic conditions and, in particular, by soil physical properties. Furthermore, Aglianico grape variety was more influenced than the Cabernet Sauvignon by environmental conditions. In conclusion, the obtained findings not only reinforce the terroir concept and our comprehension of grape's ability to adapt to climate variations but can also have implications for the future usage of grape genetic resources. [ABSTRACT FROM AUTHOR]

A new method for sensitive, specific, and direct determination of palytoxin is proposed herein. It is based on combination of reversed-phase liquid chromatography with mass spectrometry (LC--MS). The new method was set up on a turbo ion spray-triple quadrupole MS instrument operating in selected ion monitoring (SIM) and multiple reaction monitoring (MRM) acquisition modes (positive ions). The minimum detection levels for matrix-free toxin on column were thus estimated from the data to be 200 and 125 pg in SIM and MRM modes, respectively. Spiking experiments before and after extraction allowed us to assess limits of detection and quantitation for palytoxin in matrix, accuracy, and intraday and inter-day reproducibility of the method. The developed method was decisive for the analysis of a plankton sample collected along Genoa coasts in July 2005 when respiratory illness in people exposed to marine aerosols occurred. It is suggested that putative palytoxin was the causative agent responsible for patients' symptoms and demonstrated for the first time the presence of such a toxin in Italian waters.

Due to climate change and the consequent rise in grape pH, there is often the necessity of acidifying musts or wines during winemaking. In this study, the effect of early (on musts, during fermentation) and late (on wines, after the end of the fermentation) acidification was evaluated. The experimental design consisted of the preparation of seven wines from the same batch of grapes fermented in a first tank at the original pH of 3.2 and two other tanks in which the pH was adjusted to 3.5 (3.5W) and 3.9 (3.9W). On the third day of fermentation, and one week after the end of the fermentation–maceration process, aliquots of both 3.5W and 3.9W were treated to lower pH to thus obtain four more wines. After one year of aging, wines treated so as to reach a 3.2 pH significantly differed from the control wine in terms of contents of acetaldehyde, tannins reactive towards proteins and polymeric pigments. Differences were more conspicuous when acidification was carried out after the end of the fermentation–maceration process. Data highlight that the timing of acidification has a significant effect on polymerization reactions typically occurring during wine aging. [ABSTRACT FROM AUTHOR]

Highlights • Systematic analysis of bioactive molecules in red wine. • First NMR-based identification of xanthurenic acid in red wine. • First NMR-based identification of oleanic acid in red wine. • Major bioactives contained in wine from Vitis vinifera L. cv Aglianico grapes. Abstract Experimental evidence suggests that moderate consumption of wine has health promoting properties that have been mainly attributed to the wine polyphenol content. However, a systematic analysis of the major healthy molecules contained in wines has not been conducted yet. Our study explored the potential arsenal of beneficial molecules contained in wine from both a qualitative and quantitative perspective. The experimental approach was based on chromatography and untargeted NMR spectroscopy. In addition to already known bioactive molecules, for the first time, xanthurenic acid and oleanic acid were identified in wine in relatively high concentrations. On account of their many biological activities, these two molecules widen the range of potential beneficial effects of wine and pave the way toward the evaluation of their still unexplored sensory properties. [ABSTRACT FROM AUTHOR]

A detailed analysis of the causative toxins contained in the hepatopancreas of toxic mussels from the northern Adriatic Sea is described. Along with some diarrhetic shellfish poisoning (DSP) type toxins, such as okadaic acid, yessotoxin, and their derivatives, which are involved in a number of human intoxication throughout the world, a new cytotoxin, a polychlorinated sulfolipid, whose gross structure is elucidated by spectral analysis, is isolated.