Quynh Phan, James Osborne, and Elizabeth Tomasino*
*Oregon State University, 100 Wiegand Hall , Corvallis, OR 97331 (elizabeth.tomasino@oregonstate.edu)

Firm tissues of grapes and yeast are the major sources of lipids in wine. Variation of yeasts and grape varieties could impact concentration and composition of lipids. Lipid metabolism is also affected by changes in fermentation temperature. The purpose of this study was to examine changes in lipid composition of Pinot noir wines in response to different fermentation temperature and the addition of different types and amounts of yeast derivative products. Oregon Pinot noir grapes from 2017 were fermented at 8°C and 27°C. Following primary and malolactic fermentation, the yeast products Autolees and Oenolees (Laffort, USA) were added to the wines for eight weeks. Treatments included single addition of Autolees (0.3, 0.175, and 0.05 g/L), Oenolees (0.4, 0.3, and 0.2 g/L), and a mixture of Autolees (0.3 g/L) and Oenelees (0.4 g/L). Bligh and Dyer lipid extraction method with a solvent mixture of chloroform/methanol was used to extract total lipids in the experimental wines. Lipids extracted were applied onto thin-layer chromatography for purification and separation. Five lipid classes were identified as polar lipids (PL), sterols (ST), free fatty acids (FFA), triglycerides (TG), and cholesterol ester (CE). Fatty acid profile was analyzed by gas chromatography-mass spectrometry (GC-MS). The results indicate that, wine style and wine quality could be determined by lipid composition in wine. Fatty acid profile and the polyunsaturated fatty acid (PUFA) ratio n-6/n-3 could potentially be used to evaluate lipid quality in wine. It is possible that lipids may interact with other compounds in wine, such as tannins, to alter mouthfeel perception.

Funding Support: E & J Gallo Winery