Volatile Higher Alcohols Research Articles

INFLUENCE OF DIFFERENT PRETREATMENTS AND CHAPTALIZATION TYPES ON THE PHYSIOLOGICAL CHARACTERISTICS AND ANTIOXIDANT ACTIVITY OF APRICOT (PRUNUS ARMENIACA L.) WINE

The effects of pretreatment (pectinase and CaCO3) and chaptalization (sugar and puree concentrate) on the quality of apricot wine were investigated. Pectinase-treated apricot wines had increased amounts of total phenolics, flavonoid compounds, as well as antioxidant activities. The apricot wine chaptalized with puree concentrate and treated with pectinase (PCP) showed the highest total acidity and some organic acid contents, which resulted in the strongest sourness. In contrast, the apricot wine treated with pectinase and CaCO3 (SCPC and PCPC) showed the lowest total acidity and least sourness. Antioxidant activities of PCP and PCPC wines were higher than other wines, and other pectinase-treated wines were also higher than the control wine. Volatile higher alcohols and terpenes increased in all the pectinase-treated wines, whereas volatile ester compounds were decreased. Sensory evaluation showed that SCPC, PCP, and PCPC wines obtained significantly high flavor scores, and SCPC and PCPC wines obtained the highest overall preference scores.

Sequential Non-Saccharomyces and Saccharomyces cerevisiae Fermentations to Reduce the Alcohol Content in Wine

Over the last decades, the average alcohol content of wine has increased due to climate change and consumer preferences for particular wine styles that resulted in increased grape sugar levels at harvest. Therefore, alcohol reduction is a current challenge in the winemaking industry. Among several strategies under study, the use of non-conventional yeasts in combination with Saccharomyces cerevisiae plays an important role for lowering ethanol production in wines nowadays. In the present work, 33 native non-Saccharomyces strains were assayed in sequential culture with a S. cerevisiae wine strain to determine their potential for reducing the alcohol content in Malvar white wines. Four of the non-Saccharomyces strains (Wickerhamomyces anomalus 21A-5C, Meyerozyma guilliermondii CLI 1217, and two Metschnikowia pulcherrima (CLI 68 and CLI 460)) studied in sequential combination with S. cerevisiae CLI 889 were best able to produce dry wines with decreased alcohol proportion in comparison with one that was inoculated only with S. cerevisiae. These sequential fermentations produced wines with between 0.8% (v/v) and 1.3% (v/v) lower ethanol concentrations in Malvar wines, showing significant differences compared with the control. In addition, these combinations provided favorable oenological characteristics to wines such as high glycerol proportion, volatile higher alcohols, and esters with fruity and sweet character.

Effect of inoculation strategy of non‐Saccharomycesyeasts on fermentation characteristics and volatile higher alcohols and esters in Campbell Early wines

Background and Aims Wine made from the Campbell Early grape cultivar has less flavour than wine made from European grape cultivars. The aim of this study was to investigate the individual fermentation characteristics of several non‐Saccharomyces yeasts for improving the aroma of Campbell Early wine. Methods and Results Nine species of non‐Saccharomyces yeasts were used as wine starters in single or co‐fermentation with Saccharomyces cerevisiae. Several fermentation characteristics and physiological properties were investigated. Volatile higher alcohol and ester compounds were also analysed by GC/MS and by principal component analysis. Single‐fermented wines showed different fermentation kinetics, whereas co‐fermented wines showed similar, but slightly different, fermentation kinetics depending on their ethanol tolerance. Principal component analysis indicated that the composition of both volatile higher alcohols and esters was distinguishable between single and co‐fermented wines, but volatile esters in co‐fermented wines were more widely distributed compared to that in single fermented wines. Conclusions The fermentation kinetics of each strain was different. Volatile esters were more affected by co‐fermentation than volatile higher alcohols, which were produced during the early phase of fermentation. Moreover, interactions among the various volatile aromatic compounds affected the final wine aroma. Significance of the Study These findings could provide valuable information to researchers and winemakers on the enhancement of wine aroma using non‐Saccharomyces yeasts.