Quantitation of Acyl Chain Oxidation Products Formed upon Thermo-oxidation of Phytosteryl/-stanyl Oleates and Linoleates

J Agric Food Chem. 2017 Mar 22;65(11):2435-2442. doi: 10.1021/acs.jafc.7b00424. Epub 2017 Mar 14.

Abstract

A GC-based approach involving preseparation via solid-phase extraction was established for the quantitation of acyl chain oxidation products (ACOPs) formed upon thermo-oxidation (180 °C, 40 min) of oleates and linoleates of phytostanols and phytosterols. The concentrations of ACOPs resulting from initially formed 9-hydroperoxides (octanoates, 8-hydroxyoctanoates, 9-oxononanoates) were higher than those from 8-hydroperoxides (heptanoates, 7-hydroxy- and 7-oxoheptanoates, 8-oxooctanoates) in both oleates and linoleates. Significantly higher amounts of ACOPs were found in heat-treated linoleates compared to oleates. However, despite lower thermally induced losses of stanyl oleates and linoleates compared to the respective steryl esters, higher concentrations of ACOPs (approximately 9 and 10% of the ester losses, respectively) were observed in the heat-treated stanyl esters. In contrast, in the heated steryl oleates and linoleates the contribution of the ACOPs to the ester losses was lower (approximately 3 and 5%, respectively), and there was a more pronounced formation of oxidation products of the sterol moieties (approximately 26 and 18% of the ester losses, respectively).

Keywords: core aldehydes; lipid autoxidation; phytosteryl ester oxidation.

MeSH terms

  • Hot Temperature
  • Linoleic Acid / chemistry*
  • Molecular Structure
  • Oleic Acid / chemistry*
  • Oxidation-Reduction
  • Phytosterols / chemistry*

Substances

  • Phytosterols
  • Oleic Acid
  • Linoleic Acid