Effects of yeast product addition and fermentation temperature on lipid composition and sensory of pinot noir wines

Abstract

AIM: Firm tissues of grapes and yeast are the major sources of lipids in wine. Variation of yeasts and grape varieties could impact the concentration and composition of lipids in wine. Lipid metabolism is also affected by changes in fermentation temperature. The purpose of this study was to examine changes in lipid compositions and sensory in Pinot Noir wines in response to differences in fermentation temperature and addition of different types and amounts of yeast derivative products.

METHODS: Oregon Pinot noir grapes from 2019 were fermented at 16°C and 25°C. Following primary and malolactic fermentation, the yeast product Oenolees (Laffort, USA) was added to the wines. Treatments included single addition of Oenolees at different concentrations (0 g/L, 0.5 g/L, and 1.0 g/L). Bligh and Dyer lipid extraction method with a solvent mixture chloroform/methanol was used to extract total lipids in the experimental wines. Lipids extracted were subjected to lipidomic analysis using ultra-performance liquid chromatography (UPLC) to identify and analyze the lipid composition. The sensory of the final products was evaluated using triangle tests and descriptive analysis.

RESULTS: The results indicated that wine style and wine quality could be distinguished by lipid composition in wine. However, the taste and mouthfeel characteristics, sweetness, bitterness, acidity, viscosity, and drying, were not significantly different among the treatments.

CONCLUSIONS:

The wine processes of fermentation temperature and yeast product addition did not alter the lipid content of wine. While the low lipid concentration in the wine treatments resulted in no differences in the sensory study, there is much to understand about their role in compound interactions as wine ages and if this has an impact on wine mouthfeel. Lipids themselves may not have direct impacts on wine mouthfeel but there is still potential for interactions between lipids and other wine components, such as tannins, to alter wine mouthfeel perception