Levels of phytosterol oxides in enriched and nonenriched spreads: application of a thin-layer chromatography-gas chromatography methodology

J Agric Food Chem. 2005 Oct 5;53(20):7844-50. doi: 10.1021/jf050539m.

Abstract

The content of phytosterol oxidation products (POPs) in enriched and nonenriched commercial spreads was evaluated by thin-layer chromatography-gas chromatography (TLC-GC). Oxides of beta-sitosterol, campesterol, and stigmasterol were produced by thermo-oxidation (7-hydroxy, 7-keto, and epoxy derivatives) and chemical synthesis (triol derivatives), which were then separated and identified by TLC-GC. Their identification was further confirmed by GC-mass spectrometry (GC-MS). The total amounts of phytosterols found were 6.07 and 0.33 g/100 g of sample in phytosterol-enriched and nonenriched spread, respectively, whereas the total POPs contents were 45.60 and 13.31 mg/kg of sample in the enriched and nonenriched products. The main POPs found were the 7-keto derivatives of all phytosterols analyzed; 7-ketositosterol was the most abundant one (14.96 and 5.93 mg/kg of sample in phytosterol-enriched and nonenriched spread). No beta-epoxy and triol derivatives were detected in both types of samples. The enriched spread presented a lower phytosterol oxidation rate (0.07%) than the nonenriched one (0.41%).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cholesterol / analogs & derivatives
  • Cholesterol / analysis
  • Cholesterol / chemistry
  • Chromatography, Gas*
  • Chromatography, Thin Layer*
  • Food Analysis*
  • Food, Fortified / analysis
  • Margarine / analysis
  • Oxidation-Reduction
  • Oxides / analysis
  • Phytosterols / analysis*
  • Phytosterols / chemistry
  • Sitosterols / analysis
  • Sitosterols / chemistry
  • Stigmasterol / analysis
  • Stigmasterol / chemistry

Substances

  • Oxides
  • Phytosterols
  • Sitosterols
  • campesterol
  • gamma-sitosterol
  • Margarine
  • Cholesterol
  • Stigmasterol