GC-based analysis of plant stanyl fatty acid esters in enriched foods

J Agric Food Chem. 2011 May 25;59(10):5204-14. doi: 10.1021/jf104930z. Epub 2011 Apr 22.

Abstract

Approaches for the capillary gas chromatographic (GC) based analysis of intact plant stanyl esters in enriched foods were developed. Reference compounds were synthesized by enzyme-catalyzed transesterifications. Their identities were confirmed by means of mass spectrometry. Using a medium polar trifluoropropylmethyl polysiloxane stationary phase, long-chain plant stanyl esters could be separated according to their stanol moieties and their fatty acid chains. Thermal degradation during GC analysis was compensated by determining response factors; calibrations were performed for ten individual plant stanyl esters. For the analysis of low-fat products (skimmed milk drinking yogurts), the GC separation was combined with a "fast extraction" under acidic conditions. For fat-based foods (margarines), online coupled LC-GC offered an elegant and efficient way to avoid time-consuming sample preparation steps. The robust and rapid methods allow conclusions on both, the stanol profiles and the fatty acid moieties, and thus provide a basis for the authentication of this type of functional food ingredients.

MeSH terms

  • Chromatography, Gas / methods*
  • Esterification
  • Fatty Acids / analysis*
  • Food, Fortified / analysis*
  • Gas Chromatography-Mass Spectrometry
  • Linoleic Acids / analysis
  • Palmitates / analysis
  • Phytosterols / analysis
  • Plants / chemistry*
  • Yogurt / analysis

Substances

  • Fatty Acids
  • Linoleic Acids
  • Palmitates
  • Phytosterols