engleski

Lipid analysis of brewer's yeast

Interest in yeasts, as sources of oils and fats, has been renewed for their potential application in the production of highly specific fats. Brewer's yeast, byproduct of beer-industry, is used for animal feed mainly, but partially it ends in the waste water, too. For economical reasons, as well as ecological, it would be useful to find additional applications. In that aim, lipid fraction of brewer's yeast from the brewery "Karlovacka pivovara" in Croatia was analyzed. In this study the content and fatty acid composition of total lipids, the content and the composition of phospholipids and neutral lipid fraction (including sterols and squalene) were determined. The results of the analysis of lipids isolated from the biomass were obtained by standard methods of lipid analysis. Total lipid content of the yeast was low. Saturated fatty acids made 68% of total fatty acids, palmitic acid being the main in significantly higher concentration (44%) than following stearic acid (14%). The main unsaturated fatty acid was palmitoleic acid (17%). The major phospholipid components were phosphatidylcholine (33% of total phospholipids), and phosphatidylinositol and phosphatidylethanolamine in equal concentrations (22%). Sterols and squalene were analyzed along with neutral lipids. Squalene was in highest concentration, accounting for more than 30% of total lipids. This result is in agreement with high concentration of saturated fatty acids, both implying highly anaerobic conditions. Regarding relatively low lipid content of brewer's yeast, as well as low phospholipid (3% in total lipids) and high squalene content, economical production of lipids is not very likely. Since for reliable evaluation of nutritive and potential pharmacological properties more detailed data are necessary, further analysis have been undertaken.

brewers yeast; fatty acids; lipids

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