Evaluation of the antioxidant effect of thymus vulgaris extract sunflower oil used in food thermal applications

Abstract

This study was performed to investigate the retarding lipid oxidation of sunflower oil using thyme extract (TE)
compared with butylated hydroxytoluene (BHT). The sunflower oil was subjected to convection heating for 1, 4, 8, 12, and 16 hours. The analyses which were made in order to watch the progress of lipid oxidation are the
peroxid value (PV), p-anisidine value (p-AV) and TOTOX value. The antioxidant characteristics of thyme was
measured determining the ferric reducing antioxidant power (FRAP) value and total phenolics value. The results
of this study highlight that thyme extract (TE) showed a significant inhibitory effect on lipid oxidation during
heat treatment. Thyme extract in doses of 200 and 600 ppm inhibited the lipid oxidation in a similar manner to
buylated hydroxytoluen, and in a dose of 1000 ppm resulted a significant decrease of investigated indices such
as peroxid value, p-anisidine value and TOTOX value. Thyme natural extract can be used for improving
oxidative stability of sunflower oil replacing successfully butylated hydroxytoluen according to the results.