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BACKGROUND In red sparkling winemaking it is essential to obtain base wines with moderate alcohol content, adequate mouthfeel and color intensity. The aim of this work was to study oenological techniques to obtain adequate base wines for production of red sparkling wine by traditional methods: pre‐fermentative cold maceration with dry ice and délestage with premature grapes; and sugar reduction in must and partial dealcoholisation of wine with mature grapes. The effect on oenological parameters, e.g. phenolic content, foam and sensory characteristics, was studied in sparkling wines aged on the lees in bottles for 9 months followed by aging for12 months in bottles after disgorging. RESULTS Pre‐fermentative cold maceration was the only treatment that increased the content of anthocyanins in sparkling wines at both stages of aging. Sparkling wines elaborated using délestage showed the highest mean values of the degree of polymerization of proanthocyanidins. Sparkling wines from mature grapes were given higher valuation in the gustatory phase. Sparkling wines elaborated using pre‐fermentative cold maceration were given the highest valuation for foam quality. CONCLUSIONS Pre‐fermentative cold maceration is a viable alternative to common techniques for increasing the anthocyanin content in wines from premature grapes. It would therefore be a good option to obtain adequate base wines. © 2019 Society of Chemical Industry

BACKGROUND Red sparkling wines are and innovative product for the oenology market, and oenologists are looking for technologies to improve their winemaking. The present study aimed to use both carbonic maceration and pectolytic enzymes applied to premature grapes during the winemaking of red sparkling wines. Both could modify the release of polyphenols, as well as improve the foaming, aroma and sensory properties of the wines. RESULTS Red sparkling wines made with mature grapes showed the highest content of polyphenols, ethyl esters, alcohol acetates, total volatile acids and foam stability time. They were characterised by a high foam collar and foam area, full‐body, astringency, persistence, and olfactory intensity, and were the best evaluated with respect to global perception in the sensory analysis. Treatment with pectolytic enzymes was not effective with unripe grapes. These wines showed a high content of total ethyl esters and the highest content of lactones, producing wines with high olfactory intensity and fruity aromas. Red sparkling wines made by carbonic maceration showed the lowest content of total polyphenols, anthocyanins and proanthocyanidins, as well as high contents of C6 alcohols and total ethyl esters, and were characterised by vegetal aroma notes. Both treatments produced red sparkling wines with good foam characteristics. CONCLUSION Winemaking of red sparkling wines with premature grapes and pectinolytic enzymes or carbonic maceration did not achieve an improvement with respect to their chemical and sensory qualities. The use of mature grapes and traditional winemaking is the best option for elaborating red quality sparkling wines. © 2020 Society of Chemical Industry

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a b s t r a c tAim: The aim of this work was to determine the physico-chemical variables that differentiating red wines from the "Castilla y León" Spanish region by their Protected Designation of Origin (PDO) and wine category ("young", "oak", "crianza", or "reserve"). Methods and results: A total of 135 commercial red wines from four Spanish PDOs in the region of Castilla and León were analysed. Forty physico-chemical parameters, related to classical enological parameters, phenolic and polysacharidic composition, and content of higher alcohols were evaluated. Differences in physico-chemical composition were found in red wines from different PDOs and different categories. Stepwise linear discriminant analysis (SLDA) was applied to find a linear combination of the physico-chemical variables that separate and classify the red wines according to the PDO or category. One SLDA model selected 15 physico-chemical variables that allowed for good discrimination and classification of the wines from different PDOs. The SLDA model selected seven variables for wine category differentiation, but only allowed for good discrimination between young wines and aged wines ("crianza" and "reserve"). Conclusions:The variables that contributed most to the separation of Tempranillo red wines were total polyphenols, total tannins, and absorbance values at 230 nm and 280 nm. The polysaccharides with an average molecular weight of 10 kDa, flavanols, stilbenes and 2-methyl-1-butanol were those most associated with the differentiation of the wines elaborated with the Mencía grape variety. The percentage of polymeric anthocyanins and absorbance at 230 nm could be proposed as good indicators for aged wines, and total tannins for young wines. Significance and impact of the study: This study provides improved knowledge of the physico-chemical variables that could be used as markers of the origin of wines and/or the grape variety (Tempranillo and Mencía) and that allow differentiating young wines from those aged for a long time. k e y w o r d s higher alcohols, organic acids, phenolic compounds, polysaccharides, Protected Designation of Origin, red wine categories, stepwise linear discriminant analysis