Examination of lipoic acid from beer yeast by layer and capillary gas chromatography
1991
Kozma-Kovacs, E. | Halasz, A. | Hajos, Gy. (Kozponti Elelmiszerip. Kut. Int. (Hungary))
For the qualitative determination of lipoic acid (6.8-thio-octane acid) a multi-stage, two-dimension layer chromatographic, and for its quantitative determination a capillary gas-chromatographic method was elaboratored. For both determinations the lipoic acid contained in the sample - mostly bound to proteins - was released with acid hydrolysis. The determination by gas chromatography was carried out from a methylester derivative of the extract containing lipoic acid freed from solvent, the method was suitable for determining ppm quantities of lipoic acid present in the beer yeast. The lipoic acid content of the samples ranged between 2.6 and 8.3 ug/g. The largest quantity was extracted from the beer yeast autolysate (Saccharomyces carslbergensis)L (8.3 + 0.15 ug/g dust-dry sample). The literary data (3.5-9.1 ug lipoic acid/g dust-dry yeast) well agree with the results of the tests.
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