| Popis: |
A rapid and simplified technique was studied for simultaneous profiling of free and bound fatty acid and sterol contents of must and yeast by capillary gas chromatography. The protocol was designed to efficiently separate, identify, and accurately quantify the above compounds. Extracted from must with chloroform, free fatty acids and sterols were both analyzed as trimethylsilyl derivatives using a non-polar polydimethylsiloxane DB1 fused-silica capillary column. Combined fatty acids and sterols in must and yeast were saponified in aqueous ethanolic potassium hydroxide solution before chloroform extraction and silanization for GC analysis. Total run time was 77 min during which the two classes (fatty acids with chain lengths of 7–23 carbons and 10 sterols) were separated with good resolution and identified by relative retention times compared to those of the standards. This method was applied to both a grape must and yeast. Quantitative analysis was carried out with the use of three different internal standards. The simultaneous analysis of fatty acids and sterols (combined and free together) should also be applicable to other natural products and foods. |
