Grapes are rich in phenolic compounds, being important for human health with anti-inflammatory, antiatherosclerotic, antimutagenic, anticarcinogenic, antibacterial, antiviral, and antimicrobial activity. The winemaking of the grapes generates significant amounts of waste. These wastes contain bioactive compounds in their biomass that can be used as a source of food improvement or as a source of nutrition supplementation. This study looks at the content of bioactive compounds, the polyphenolic profile, and the antioxidant activity in different white and red grape pomaces. The investigation of bioactive characteristics (total polyphenols, total flavonoids, catechins, tannins, and antioxidant activity) was carried out by UV-Vis spectrophotometric methods, while the individual polyphenolic composition was investigated by target and screening UHPLC-HRMS/MS analysis. Principal components (PCA) and the heat maps analysis allows the discrimination between the grape pomace resulted from white grape cultivars (Muscat Ottonel and Tamaioasa Romaneasca) and red grape pomaces (Cabernet Sauvignon, Merlot, Feteasca Neagra, Burgund Mare, Pinot Nore), with the identification of the specific phenolic compounds for each grape pomace type.

Wine contains important amounts of antioxidants, which contribute to the protection of the body from oxidative stress and associated diseases. This study aims to characterize the bioactive characteristics and individual polyphenolic composition of different white and red musts and the corresponding wines obtained at Stefanesti vineyard, Romania, and to observe the evolution of the main phenolic compounds from the musts to the corresponding wines. General bioactive characteristics (total polyphenols, total tannins, total catechins, total anthocyanins contents, total tannin, and antioxidant activity) were determined using UV-Vis spectrometric methods, while phenolic composition (phenolic acids, flavonoids, and stilbenes) was detected using UHPLC–HRMS analysis. The fermentation and stabilization processes that occur during the transformation of musts into the corresponding wines lead to a decrease in the general bioactive characteristics from musts to wines, while the fermentation of the musts leads to an enrichment of the individual phenolic compounds in the corresponding wines, with a significant increase in the content of gallic, syringic, and p-coumaric acids in the wines compared with the musts. A clear distinction of the musts and wines was obtained for both white and red varieties, indicating different phenolic compositions of the musts and wines. The obtained results contribute to the characterization of the polyphenolic fingerprint of the investigated white and red musts and wines.

The characteristics of the variety from which the wine is made, the geographical area of production, the year of production, and the technology of winemaking are the parameters with the most influence on the total content of polyphenols, the polyphenolic profile, and the antioxidant activity of wine. For this reason, a polyphenolic screen can help establish the authenticity of wines. For this study, 50 samples of white and red wine from different wine areas were collected. For these samples, a qualitative and quantitative analysis was carried out on the polyphenolic profile. The polyphenolic profiles of the studied wines were determined using UHPLC-ESI-MS/MS (mass spectrometry with tandem ionization with high-performance liquid chromatography). Among the non-flavonoid acids, gallic acids, p-coumarnic, and syringic acids in red wines showed higher concentrations in all samples, while resveratrol was present in concentrations from 0.605 to 12.38 mg/L in red wines, and white wines ranged from 0.07 to 0.35 mg/L. For flavonoids, -catechin (0.187 m/L–130.98 mg/L in red wines and 0.04–4.45 mg/L) and (-)-epi-catechin showed the highest concentrations, reaching up to 29.78 mg/L in red wines.

The methods applied for DNA extraction from must and wine samples with monovarietal origin are presented and discussed aiming to prove the quality of extracted DNA and its good properties for further use in molecular tests. In the present research were compared four different DNA extraction methods from must and wine samples obtained from eleven V. vinifera varieties (five grapevine varieties for white wines and six grapevine varieties for red wines, respectively). Taking into consideration the amounts of obtained DNA, the concentrations and purities of the final DNA extracts, were stood out two modified methods. For all must samples, very efficient was the second method, which allowed obtaining a mean value of 87.9 ng µl-1 for the DNA concentration with 1.55 purity. Among the tested procedures, for monovarietal wine samples, the fourth method proved to be the most efficient which brought a mean value of 64.7 ng μl-1 for DNA concentration with 1.66 purity. This method adequate for wine samples involves two CTAB solution treatments and the RNase treatment applied before DNA resuspension. The DNA from must and wine extracts and the DNA from leaves of the corresponding grapevine varieties were amplified with five specific microsatellite primers (VVS2, VVMD27, VVMD32, VrZAG79 and VrZAG62). The aspects of pattern profiles were analysed in parallel and proved that the extracted DNA was suitable for amplification with these specific V. vinifera primers. The two selected extraction procedures are considered good for research purposes and ensure obtaining of good-quality extracted DNA from musts and one-year old wines.

As compared to red wine technology, where pomace is macerated, the grape juices and musts are obtained by pressing the grapes and removing the pomace, thus removing an important source of antioxidant molecules. The objective of this study was to exploit the bioactive compounds from the black grape pomace and obtain a new food product, namely pasteurized red must with improved health-promoting properties. The study was conducted on four grape varieties for red wines—Fetească Neagră, Cabernet Sauvignon, Blauer Zweigelt, and Arcaș—each coming from a certain recognized Romanian vineyard, as follows: Murfatlar, Dealu Mare, Ștefănești-Argeș, and Iași, respectively. Both the must and the pomace extract used for each product were from the same variety and region. The recovery of polyphenols was achieved by macerating the pomace at ambient temperature, using solutions of ethanol in concentrations of 25%, 50%, and 75%. The results showed that the most efficient method of polyphenol recovery was obtained by using the ethanolic solution of 50%, which was selected for the subsequent stages of the study. The selected hydroalcoholic extract was concentrated by eliminating the solvent by roto evaporation and used as a source of supplementary bioactive compounds for the pasteurized must. The phenolic profiles of the musts enriched with phenolic extracts were determined by liquid chromatography, UHPLS-HRMS, revealing significant increases in the content of individual phenolic acids and other polyphenols. The phenolic extract recovered from the pomace significantly optimized the phenolic quality of the pasteurized must, thus contributing to the improvement of its nutritional value. The new product has a phenolic profile close to that of a red wine, but does not contain alcohol. Also, this technology is a sustainable method to convert grape waste into a safe, antioxidant-rich grape juice with potential health benefits.