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Vitis vinifera grapevine plays an important role in the economy of many countries across the world. Its susceptibility to fungi diseases has forced a massive use of pesticides dangerous to the environment and hazardous to human health. As a consequence, there has recently been a shift toward a disease prevention approach based on the development of fungi-resistant grapevines obtained by the introgression of specific resistance genetic traits (PIWI varieties). Such varieties seem to have enough potential to produce high-quality wines, but little is currently available on their evolution over time. The purpose of this study was to investigate the aging behavior of two disease-resistant red wines (from ′′Cabernet Eidos′′ and ′′Merlot Khorus′′ varieties, respectively) in comparison with a red wine (obtained from the elite cultivars ′′Cabernet Sauvignon′′ and ′′Merlot′′) renowned for its longevity. The analyses were conducted soon after the wine production and again after a 2 year aging. The phenolic composition of the wines (anthocyanins, flavanols, flavonols, and stilbenes) was quite different from both a quantitative and qualitative standpoint. The amount of both tannins and flavans detected after 2 years was at least four times higher in the disease-resistant wines compared to the control wine. Additionally, the color intensity of the disease-resistant wines was at least twice that of the wine used as control even after a 24 month aging. The above results suggest a different aging behavior of the disease-resistant red wines and provide a fundamental background for viticulturists and enologists to better exploit the qualitative potential of disease-resistant cultivars.

Minor grape varieties often possess key traits to produce wines with specific territorial identity. Italy is home to a wide selection of autochthonous grapevines. In 2005, four white grape varieties from the Amalfi coast, Fenile, Ginestra, Pepella and Ripoli were registered in the National Catalogue grapevines. They are all complementary varieties with a rich biodiversity and linked to an ancient wine heritage. Studies on such varieties have not been conducted yet. Here, the metabolite content of the above four grape varieties is described. Ripoli was the richest in quercetin derivatives while very low was the content of kaempferol derivatives; Pepella possessed an equal amount of quercetins and kaempferols; Ginestra and Fenile featured a quercetins abundance twice that of kaempferols. Also, the (+)-catechin content was higher than (–)-epicatechin’s; B-type procyanidins occurred in higher concentrations in Pepella and Ripoli than in Fenile and Ginestra. Hydroxycinnamic acids were also identified and quantified. Seeds from each variety were carefully analyzed and flavanols were identified up to decamers along with their galloylation percentage. The obtained data are a tool of variety differentiation and useful to develop appropriate vinification procedures to ameliorate the quality of wines.

Grape pomace, a bulky component of winery waste, is a source of healthy compounds. So far, scientific research has mainly focused on its polyphenol content, but given the impressive number of bioactivities shown by grape pomace, it is not unlikely that, besides polyphenols, additional metabolites, so far undetected, may be involved. In order to verify such hypothesis, an in-depth chemical analysis of Aglianico (Vitis vinifera) grape pomace was conducted by NMR and LC-MS/MS. In addition to a number of polyphenols, a remarkable concentration of oleanolic acid (0.45 mg/g - fresh weight) was determined in the analyzed material. Oleanolic acid is a natural triterpenoid showing many bioactivities including antitumor, anti-inflammatory, antibiotic and antiviral properties. Also, it was proven a potential antidiabetic molecule in Type1 Diabetes rats. Hence, its influence on the mitochondrial and glucose uptake activities of C2C12 myoblast was here assessed, thus supporting oleanolic acid as a promising antidiabetic metabolite.

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.

Anthocyanins are natural pigments responsible for the typical color of red wines and are critically associated with the wine commercial value and longevity. Thus, understanding the molecular bases of the anthocyanin chemical behavior in the complex wine environment is a central issue to the enological sector. By setting up a nuclear-magnetic-resonance-based experimental protocol, new important insights into the chemistry of malvidin-3- O-glucoside, a major wine anthocyanin, in model solution have been provided. Two new equilibrating isomers of the anthocyanin have been identified and quantified at typical wine pH values. More importantly, the key role of pH in determining the solubility and co-pigmentation process of malvidin-3- O-glucoside has been clarified. Consequently, a value of pH of about 3.3 or lower favors co-pigmentation while inhibiting the precipitation of significant quantities of anthocyanins during the maceration-extraction phase of the winemaking.

Background: Numerous oenological practices can cause an excess of dissolved oxygen in wine, thus determining sensory and chromatic defects in the short‐ to long‐term. Hence, it is necessary to manage the excess of oxygen before bottling. Methods: In this study, the management of the dissolved oxygen content by a polypropylene hollow fiber membrane contactor apparatus was performed in two wines from different grape varieties (Aglianico and Falanghina). The wines were analyzed after an 11‐month aging. Anthocyanins and acetaldehyde content were evaluated by HPLC. In addition, other phenolic compounds and chromatic characteristics were analyzed by spectrophotometric methods. NMR and HR ESIMS analyses were conducted to evaluate the amount of pyranoanthocyanins and polymeric pigments. Results: After 11 months of aging, in both wines a decrease of free and total SO2 with respect to initial values was detected. In the wines with the highest dissolved oxygen levels, a more remarkable loss was observed. No significant differences in terms of color parameters were detected. In red wine with the highest oxygen content, a massive formation of polymeric pigments and BSA reactive tannins was observed, as opposed to wines with lower oxygen levels. Conclusion: The study demonstrated that the membrane contactor can prove a successful tool to manage dissolved oxygen in wines as to prevent their oxidative spoilage. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.