Utilization of Wort Fatty Acids by Yeast During Fermentation

Uniformly labeled C-palmitic, oleic, and linoleic acids were used individually to trace wort fatty acids in ale yeast fermentations. Fatty acids extracted from the resulting beers were analyzed by gas-liquid chromatography with concurrent radioactivity monitoring. Lipid components extracted from the harvested yeast were separated by thin-layer chromatography, and the fatty acyl residues of these components were subjected to the same radio-gas chromatographic analysis. Results indicate that wort fatty acids are incorporated into the yeast cell as structure lipids, mainly in the forms of free fatty acid and phospholipid. The relationship between wort and beer fatty acid is indirect. This means that wort fatty acids contribute to the growth and maintenance of yeast, the activity of which, in turn, determines the formation and release of shorter chain fatty acids into beer.