Influence of maceration time on phenolic compounds and antioxidant activity of the Syrah must and wine

Influence of Cold Pre-Fermentation Maceration on the Volatilomic Pattern and Aroma of White Wines

Aroma compounds play a key role in wine quality due to their importance in wine aroma. The aim of the present study is to investigate the influence of cold pre-fermentative maceration (CPM) treatment on aromatic and sensory properties of white wines from four grape varieties (Tempranillo Blanco, Maturana Blanca, Viura and Garnacha Blanca) during two consecutive years (2019 and 2020). A total of 62 aroma compounds belonging to different chemical families were identified using headspace solid-phase microextraction combined with gas chromatography mass spectrometry (HS-SPME/GC-MS). CPM treatment enhanced the total relative concentration of alcohols, esters and acids compared to control wines. Regarding sensorial properties, esters made the greatest contribution to the studied white wines, mainly through the development of floral and fruity notes. On the other hand, CPM treatment did not significantly influence the total relative concentration of terpenoids, and different trends were observed according to grape variety and vintage. The obtained results showed differences in the wine's aromatic complexity according to the grape variety, the vintage and the treatment applied and suggested that CPM treatment could represent a suitable approach to manipulate the aromatic profile and enhance the aromatic quality and complexity of wine.

Ultrasound-assisted production of alcoholic beverages: From fermentation and sterilization to extraction and aging

Ultrasound is sound waves above 20 kHz that can be used as a nonthermal ''green'' technology for agri-food processing. It has a cavitation effect, causing bubbles to form and collapse rapidly as they travel through the medium during ultrasonication. Therefore, it inactivates microorganisms and enzymes through cell membrane disruption with physicochemical and sterilization effects on foods or beverages. This emerging technology has been explored in wineries to improve wine color, taste, aroma, and phenolic profile. This paper aims to comprehensively review the research on ultrasound applications in the winery and alcoholic beverages industry, discuss the impacts of this process on the physicochemical properties of liquors, the benefits involved, and the research needed in this area. Studies have shown that ultrasonic technology enhances wine maturation, improves wine fermentation, accelerates wine aging, and deactivates microbes while enhancing quality, as observed with better critical aging markers such as phenolic compounds and color intensity. Besides, ultrasound enhances phytochemical, physicochemical, biological, and organoleptic properties of alcoholic beverages. For example, this technology increased anthocyanin in red wine by 50%. It also enhanced the production rate by decreasing the aging time by more than 90%. Ultrasound can be considered an economically viable technology that may contribute to wineries' waste valorization, resource efficiency improvement, and industry profit enhancement. Despite numerous publications and successful industrial applications discussed in this paper, ultrasound up-scaling and applications for other types of liquors need further efforts.

Chemical typicity of tropical tannat red wines from sub-middle São Francisco Valley, Brazil

Tannat is a Vitis vinifera cultivar with typically high phenolic compound contents, showing intense coloration, well-bodied, and great aging potential. However, even with this great potential, this variety is still commercially underexplored in the Sub-middle São Francisco Valley (SSFV). This work aimed to characterize the typicity of Tannat red wines from Sub-middle São Francisco Valley (SSFV), Brazil. In addition, the present work represents the first study featuring phenolic compounds quantification and antioxidant activity of Tannat in tropical climate wine-producing regions. Considering the condition of a short-applied maceration time during the winemaking, the tropical Tannat wine showed significant antioxidant activity and high phenolic contents. Trans-caftaric, malvidin-3-O-glucoside, and procyanidin B1 stood out among the phenolic compounds quantified, presenting Tannat with the potential to be an important grape variety to tropical wine-producing regions in Brazil, containing high contents of bioactive compounds. Previously results to compounds (-)-epigallocatechin gallate, procyanidin B2, quercetin-3-β-D-glucoside, pelargonidin-3-O-glucoside, chlorogenic acid, and piceatannol were not found in Tannat wines. Further studies are necessary to make the Tannat grape's adaptation better in tropical climate conditions, including investigating the phenolic profile and antioxidant activity of Tannat red wines with longer maceration times during the winemaking.

Graphical abstract

1H NMR and UPLC-HRMS-based metabolomic approach for evaluation of the grape maturity and maceration time of Touriga Nacional wines and their correlation with the chemical stability

Touriga Nacional is a well-adapted Portuguese grape variety in São Francisco River Valley (northeastern Brazil). Nevertheless, it has only been indicated to short-term consumption because of the lack of chemical stability, which is attributed to low grape acidity and incomplete phenolic maturity. Therefore, we used Ultra-Performance Liquid Chromatography coupled High-resolution Mass Spectrometry, Nuclear Magnetic Resonance and chemometrics (PCA and PLS-DA) to evaluate the grape maturity and maceration time on chemical composition of wines from two harvest seasons. Moreover, we investigated how these experimental factors could affect their chemical stability. Grapes maturity showed to be the main effect. Overall, phenolic acids and short-chain organic acids were found to be at higher levels in wines produced with unripe grapes from February and shorter maceration time (p < 0.05). Proanthocyanidins and other flavonoids were increased in wines macerated for longer time using overripe grapes harvested in July. Furthermore, stable wines were made from overripe grapes, which contained more galacturonic acid.

Influence of keeping the calyces during fermentation on physicochemical and sensory properties of Hibiscus sabdariffa wines

Hibiscus (Hibiscus sabdariffa) wines are usually made through the fermentation of its calyces extracts. However, the exhausted calyces could still contain a considerable amount of extractable bioactive compounds. This work analyzed the effect of keeping the hibiscus calyces during fermentation on the physicochemical and sensory characteristics and acceptance of its wines. Hibiscus wines Filtered-Ch and Filtered-C were generated by fermentation of filtered musts of China and Colima varieties, respectively, while Unfiltered-Ch and Unfiltered-C were obtained by fermentation of musts from calyces that were kept for 120 days. Unfiltered-C and Unfiltered-Ch wines had higher contents of total monomeric anthocyanins (32.5 mg/L in Unfiltered-C and 48.5 mg/L in Unfiltered-Ch), condensed tannins (around 200 mg_CE/L), total phenolic compounds (800 mg_GAE/L), and antioxidant activity (8.4-8.8 mM_TE/L), as well as a higher concentration of tartaric, citric and malic acids (0.26, 0.32 and 2.25 g/L, respectively) than Filtered-C and Filtered-Ch wines (P < 0.05). Moreover, Unfiltered-C and Unfiltered-Ch wines had darker red colors, evidenced by lower lightness, chroma and hue values, than those observed in Filtered-C and Filtered-Ch wines (P < 0.01). Furthermore, Unfiltered-Ch and Unfiltered-C wines were more appreciated, having a more intense taste and smell according to the descriptions obtained from consumers by applying the Check-All-That-Apply technique. Sensory attributes observed in hibiscus wines were statistically correlated with the physicochemical characteristics. Keeping hibiscus calyces during fermentation allows for the production of wines with acceptable sensory characteristics and a higher concentration of bioactive compounds than producing wines from filtered musts.

Effect of Drying Methods on Bioactive Compounds and Antioxidant Capacity in Grape Skin Residues from the New Hybrid Variety "BRS Magna"

The effects of the drying process using the conventional oven and freeze-drying on the thermogravimetric profile, proximate composition, color parameters, individual bioactive compounds, and antioxidant activity in the grape residue (skin) were evaluated. Twenty individual phenolic compounds were identified, where a variation in concentration was observed for flavonols, stilbenes, phenolic acids, flavonoids, procyanidins, and particularly anthocyanins (malvidin-3,5-di-O-glucoside of 253.2-536.9 mg/kg) due to the drying process. Drying in a conventional oven caused a decrease of 23% of the total polyphenols. The skin of the BRS magna grape has a high concentration of total phenolic content of 489.5-148.3 mg.GAE/100 g, total anthocyanin content of 124.9-260.1 mg.CE/100 g, and total flavonoid content of 12.7-26.0 mg.QE/100 g. The results of free radical scavenging activity (1.26-4.91 μg/mL, as EC50) and ferric reducing antioxidant power (82.93-184.10 μmol/g of skin as equivalent to Fe2SO4) indicate high antioxidant activity, independently of the drying process applied. It was concluded that, if the application is directed to anthocyanin compounds, the use of lyophilization is recommended. On the other hand, if the interest is in bioactive compounds that exert antioxidant activity, conventional oven-drying can be used.