OXIDATIVE STABILISATION OF SUNFLOWER OIL BY ANTIOXIDANT FRACTIONS FROM SELECTED LAMIACEAE HERBS

Abstract

This study reports the effect of antioxidant fractions from rosemary (Rosma-rinus officinalis), sage (Salvia officinalis), thyme (Thymus vulgaris) and hyssop (Hyssop officinalis) on the oxidative stability of sunflower oil at elevated tempe¬rature. In order to isolate antioxidant fractions, the method of fractional super¬critical extraction with carbon dioxide at 35 MPa and 100 C was applied. Anti¬oxidant fractions were added to sunflower oil at concentrations of 200 mg/kg oil and the samples were stored in an oven maintained at 98 C. The antioxidant activity of the extracts was determined by measuring peroxide values (PV). Among investigated extracts, the rosemary extract was most effective on retarding lipid oxidation of sunflower oil. The antioxidant activity of the extracts was com¬pared to the activity of butylated hydroxyanisole (BHA) and a commercial rose¬mary extract Flavor’ Plus. On the basis of PV assay, the antioxidant activity of the investigated plant extracts after 12 h of storage at 98 C followed the order: rosemary extract > BHA > sage extract > Flavor’ Plus > thyme extract > hyssop extract.

Keywords

• peroxide value
• rosemary
• sage
• thyme
• hyssop
• supercritical extraction