Effects of Antioxidants
on Rapeseed Oil Oxidation in an Artificial Digestion Model Analyzed
by UHPLC–ESI–MS
- Publication date
- Publisher
Abstract
A normal diet contains large quantities of oxidized fatty
acids, glycerolipids, cholesterol, and their cytotoxic degradation
products because many foods in the diet are fried, heated, or otherwise
processed and consumed often after long periods of storage. There
is also evidence that the acid medium of the stomach promotes lipid
peroxidation and that the gastrointestinal tract is a major site of
antioxidant action, as demonstrated by various colorimetric methods.
The identity and yields of specific products of lipid transformation
have seldom been determined. The present study describes the molecular
species profiles of all major gastrointestinal lipids formed during
digestion of autoxidized rapeseed oil in an artificial digestion model
in the presence of l-ascorbic acid, 6-palmitoyl-<i>O</i>-l-ascorbic acid, 3,5-di-<i>tert</i>-butyl-4-hydroxytoluene
(BHT), dl-α-tocopherol, and dl-α-tocopheryl
acetate. Differences in oxidized lipid profiles were detected in the
samples digested in the presence of different antioxidants, but none
of them could prevent the formation of oxidized lipids or promote
their degradation in a gastric digestion model. The lack of effect
is attributed to the inappropriate nature of the gastrointestinal
medium for the antioxidant activity of these vitamins and BHT. A fast
ultrahigh performance liquid chromatographic–electrospray ionization–mass
spectrometric method was developed for the analysis of lipolysis products,
including epoxy, hydroperoxy, and hydroxy fatty acids, and acylglycerols,
utilizing lithium as ionization enhancer