Dependence of Oak-Related Volatile Compounds on the Physicochemical Characteristics of Barrel-Aged Wines

U ovom je radu ispitan utjecaj nekih fizikalno-kemijskih značajka, kao što su hlapljiva kiselost, titracijska kiselost, pH-vrijednost, udjel slobodnog SO2 i alkohola na akumulaciju hlapljivih spojeva u vinima odležalim u hrastovim bačvama. Pokušala se razriješiti kontradiktornost dobivenih rezultata u usporedbi s rezultatima drugih autora. Upotrijebljene su tri različite sorte vina, što su odležale 12 mjeseci u bačvama sličnih osobina (iz iste bačvarije, od istoga drveta, jednako tostirane, tj. paljene i istoga volumena), a pokus je ponovljen tijekom dvije uzastopne godine. Rezultati pokazuju da su volumni udjel alkohola u vinu i njegova titracijska kiselost u pozitivnoj korelaciji s konačnom koncentracijom vanilina i gvajacilnih spojeva u dozrelim vinima, a u negativnoj korelaciji sa cis- i trans-β-metil-γ-oktalaktonom. Stoga se pri ispitivanju utjecaja osobina hrastovih bačava (porijeklo i sezona rasta hrasta, veličina bačve, učestalost korištenja itd.) na koncentraciju hlapljivih spojeva u vinu također trebaju uzeti u obzir fizikalno-kemijske značajke vina, osobito titracijska kiselost i volumni udjel alkohola, jer konačna aroma vina ovisi i o tim značajkama.This paper focuses on the effect of some of the physicochemical characteristics of wines such as volatile acidity, titratable acidity, pH, free SO2 and alcohol content on the accumulation of oak-related volatile compounds in barrel-aged wines, in order to give more light on the contradictory results found by other authors in this respect. For this, three different single variety wines were aged for twelve months in barrels with the same characteristics (same cooperage, wood origin, toasting level and volume), repeating the experiment in two consecutive years. Our results show that the percentage of wine alcohol and its titratable acidity positively correlated with the final concentration of vanillin and guaiacyl compounds in the oak-matured wines and negatively with the cis- and trans-β-methyl-γ-octalactone concentration. Therefore, when studying the effect of oak barrel variables (oak origin and seasoning, size of the barrel, number of uses, etc.) on the concentration of oak-related volatile compounds in wine, the effect of the physicochemical variables of the wine, especially titratable acidity and alcohol content, should also be taken into account since the final wine aroma composition will also depend on these characteristics

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

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

Características y constituyentes aromáticos en uvas de la variedad Monastrell, Tempranillo y Cabernet Sauvignon y durante su vinificación / Encarna Gómez Plaza ; director José Laencina Sánchez.

Tesis-Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M.-730.CRAI CIENCIAS. DEPOSITO. TD 163

Características y constituyentes aromáticos en uvas de la variedad Monastrell, Tempranillo y Cabernet Sauvignon y durante su vinificación [Microforma].

Tesis - Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. MEDIATECA. MF-TD 1587.NEBRIJA. MEDIATECA. MF 25 1078.NEBRIJA. MEDIATECA. MF 25 1077

Elicitors: A Tool for Improving Fruit Phenolic Content

Fruits are one of the most important sources of polyphenols for humans, whether they are consumed fresh or as processed products. To improve the phenolic content of fruits, a novel field of interest is based on results obtained using elicitors, agrochemicals which were primarily designed to improve resistance to plant pathogens. Although elicitors do not kill pathogens, they trigger plant defense mechanisms, one of which is to increase the levels of phenolic compounds. Therefore, their application not only allows us to control plant disease but also to increase the phenolic content of plant foodstuffs. Pre- or post-harvest application of the most commonly used elicitors to several fruits is discussed in this review

Biochemistry of Wine and Beer

Today, the production of wine and beer is a worldwide industry worth millions of euros annually, with breweries and wineries throughout the globe [...