High power ultrasounds: A powerful, non-thermal and green technique for improving the phenolic extraction from grapes to must during red wine vinification

Wine color is one of the main organoleptic characteristics influencing its quality. It is of especial interest in red vinifications due to the economic resources that wineries have to invest for the extraction of the phenolic compounds. To increase this extraction, some chemical (maceration enzymes) or physical technologies (thermovinification, criomaceration, flash-expansion) can be applied. In this work, the results of the application of high power ultrasounds to the crushed grapes to increase the extraction of phenolic compounds are presented. Crushed grapes (400 kg) from the 2017 harvest were treated with ultrasound, and three different lengths of skin maceration period (2, 3 or 7 days) and the results were compared with a control vinification, where grapes were not subjected to any treatment and were skin macerated during 7 days. The wine chromatic characteristics and the individual phenolic compounds were followed during all the maceration period, at the end of alcoholic fermentation and after bottle storage. The wines made with ultrasound treated grapes presented differences with control wine, especially as regard color and total phenol and tannin content, the wines with three days of maceration time presenting similar chromatic characteristics than control wines with 7 days of maceration time

Ultrasound treatment of crushed grapes: Effect on the must and red wine polysaccharide composition

This paper studied the effect on the molecular weight and polysaccharide composition of musts and wines of the application of high-power ultrasound (US) at 20 and 28 kHz on crushed grapes. Two different pomace maceration times (short and mid) were tested for sonicated and control vinifications. A long pomace maceration time was also tested for non-treated wines. In must samples, US significantly increased the content of monosaccharides and polysaccharides rich in arabinose and galactose (PRAG), and the average molecular weight of smaller PRAG, mannoproteins (MP) or mannans. The 28 kHz had a major effect on most wine monosaccharides and grape polysaccharides. The wine obtained from sonicated grapes at 28 kHz and with mid maceration had higher rhamnogalacturonans type II and PRAG content than its control, and closer polysaccharide and monosaccharide content to long maceration control wines. No significant differences were obtained in the MP content between sonicated and control wines.This research was funded by the Ministerio de Ciencia, Innovación y Universidades from the Spanish Government and Feder Funds, grant number RTI2018-093869-B-C21

Reemplazo de la estabilización tartárica por frío en las bodegas: El uso de carboximetil celulosa, poliaspartato de potasio y resinas intercambiadoras de iones

El tratamiento de los vinos antes del embotellado para evitar la precipitación de las sales del ácido tartárico es un paso importante y común durante la producción del vino. La estabilización en frío es el tratamiento de estabilización más utilizado, y aunque ha demostrado ser efectiva, presenta algunas desventajas significativas. Estas son las razones por las cuales se están introduciendo otros productos y metodologías en las bodegas. Algunas de estas nuevas técnicas implican la reducción de la concentración de ácido tartárico y/o potasio en los vinos. Otras son técnicas aditivas y utilizan coloides protectores o inhibidores de la cristalización de las sales. En este estudio, se han tratado con carboximetilcelulosa, con poliaspartado de potasio y con resina de intercambio iónico vinos blancos, rosados y dos tipos diferentes de vinos tintos. Se estudiaron las características enológicas y cromáticas de los vinos y se evaluaron también sensorialmente. Los resultados indican que las características sensoriales y cromáticas se mantuvieron en los vinos (en comparación con un vino de control no tratado) con el uso de la carboximetilcelulosa y el poliaspartato, no detectándose diferencias en la mayoría de los casos en una prueba sensorial triangular en el caso de la carboximetilcelulosa y siendo los vinos tratados con poliaspartato de potasio evaluados positivamente

Effect of fining with new plant proteins on the aroma composition, phenolic compounds, and color of a Monastrell wine

The wine industry has increased its interest in finding new fining agents, and vegetable proteins have received increasing attention. Quinoa and kiwicha are native pseudocereals to the Andean highlands with high protein content and are considered gluten-free products. This work aimed to determine the effect of fining with quinoa and kiwicha protein extracts (QP and KP respectively) at different doses (30 and 50 g/hL) on the aroma composition, color, and phenolics of a Monastrell wine compared to pea proteins and gelatin. Fining treatments produced no significant reduction of TPI. Except for QP at 30 g/hL and the lowest dose of pea proteins, the fining treatments decreased the content of total anthocyanins. The doses of 50 g/hL of QP and KP were particularly efficient, producing the largest decrease in total tannins. Analyses by size exclusion chromatography showed that treatments with QP and KP were capable of selectively removing high molecular weight phenolics. All fining agents slightly decreased the color intensity. All fining treatments showed a significant decline in total ester concentration (26-45%). Instead, total alcohols remained constant upon the fining treatments. Five terpenes were identified in all wines, and their content was not affected by the fining treatments

The effect of yeast on the anthocyanin characteristics of fermented model solutions

The sensory quality of red wines is basically determined by the colour, which depends on the amount and on the evolution of anthocyanins and other phenolic compounds extracting from the berries into the wine during wine-making. The anthocyanin-monomers are responsible for the development of the red colour, and their acylated derivatives provide stability for the colour of the wines. The anthocyanin profile of wines is affected by several factors: the grape variety, the conditions during wine-making, and also the yeast culture used for the fermentation. In our experiments a self-compiled model solution was fermented by spontaneous fermentation, as well as by four commercial yeasts under laboratory conditions. After fermentation total polyphenolics, anthocyanins, anthocyanin monomer profile, colour intensity, hue, and the ratio of polymeric anthocyanins were studied. Our results show that the spontaneous yeast fermentation resulted in a higher anthocyanin concentration in the fermented model solution, but the commercial yeast strains provided a more advantageous colour characteristic compared to the spontaneous fermentation. After the spontaneous fermentation less sediment was left than in the commercial yeast fermented samples

Effect of enological tannin addition on astringency subqualities and phenolic content of red wines

Four Italian red wine varieties (Sangiovese, Montepulciano, Barbera, Nero d'Avola) were used to investigate the effect of enological tannins on astringency characteristics and phenolic content of red wines. Wines were treated with three tannins of different origins (G = grape, E= oak, and P = exotic wood) at two concentrations (10, 20 g/hl) and aged for 1 year. Wines were evaluated for astringency and for 16 subqualities using check-all-that-apply questions. In addition, polymeric pigments, tannins, flavans, total anthocyanins, and color parameters were analyzed. Enological tannin promoted color stability by pigmented polymers formation. Astringency intensity was not enhanced, even better an improvement of mouthfeel sensations was achieved with wood-derived tannins. Multivariate analysis revealed a great influence of the variety on astringency and phenolic characteristics of wines. Therefore, the initial phenolic composition of wine seems to be the main driver of the evolution of wine during aging. Practical applications: Tannin addition is an enological practice widely widespread because of many economical benefits. The use of enological tannins during aging can contribute to color stabilization and to an improvement of astringency subqualities of wines. Training on astringency subqualities with touch standards coupled with the check-all-that-apply questions can provide an interesting way to reveal the different aspects of red wine astringency. Despite high astringency and high phenolic content, a wine may present desirable subqualities which can improve wine experience. Finally, a tailored use of enological tannins depends on wine variety

Reuse of oak chips for modification of the volatile fraction of alcoholic beverages

New or used barrels can be applied in ageing of alcoholic beverages. Compounds adsorbed in wood migrate between beverages along with wood extractives. As barrel ageing is costly and time-consuming, processes using wood fragments have been gaining interest. These generate wood residues for which the reuse is still not well established. This work aims at the reuse of oak fragments for the additive ageing of alcoholic beverages. Oak chips, previously immersed in fortified wine, were applied to beer, wine and grape marc spirit. Wood compounds and adsorbed wine volatiles were extracted, with more impact and satisfactory yields on beer composition. Also, wood adsorbed beverages compounds in a subtractive ageing phenomena. Beer formulations using different binomial wood concentration/temperature combinations were generated and presented to trained tasters. Higher temperatures and wood concentrations led to prominence of wood descriptors and lower perception of fruity and floral aromas, reflecting the changes in chemical composition.Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. Fermentum – Engenharia das Fermentações Lda. also participated in co-funding and provided beer samples used in this work, which authors would like to acknowledge. Lastly, authors would like to thank Mr. Benoît Verdier and Seguin Moreau for supplying the woods and Mr. Paulo Coutinho and Quinta do Portal for supplying the fortified wineinfo:eu-repo/semantics/publishedVersio