A Fast GC-MS-Based Method for Efficacy Assessment of Natural Anti-Oxidants for Inhibiting Lipid Oxidation

For health reasons it is preferred to prepare food products with edible fats and oils that are high in unsaturated fatty acids. Unfortunately, these unsaturated acids are susceptible to lipid oxidation and the addition of natural antioxidants, e.g., rosemary extracts, etc. is needed.

To assess the efficacy of natural oxidation inhibition strategies, fast, yet realistic, and objective methods are needed to study oxidation inhibition.

A model system consisting of salt and sunflower oil is proposed as a model for dry soups and sauces. Hexanal formation is studied using fast GC-MS as a quantitative indicator for lipid oxidation.

A fast GC-MS method using a short, 6-m 150 µm inner-diameter column was developed that allowed elution of hexanal within approximately 20 s, with a total run time of 2 min. The GC method has quantification limits below 1 ppm and is hence much more sensitive than the human nose.

The new accelerated method with hexanal read-out was successfully applied in a study to identify spices and herbs mixtures that can act as natural inhibitors of lipid oxidation. The fast GC-MS method is extremely stable and allowed the analysis of thousands of samples with very little maintenance.

With the right mixture of spices and herbs, lipid oxidation can be delayed more than 100 times as compared to non-stabilized systems.