The oxidative stability of sunflower oil containing rosemary essential oil and extracts in the oil during frying were followed by measuring peroxide value. Variation in the values of L* of the frying oil containing extract was less than that of frying oil containing essential oil. a*-Value of the fried oil containing extract highly significant decreased. Increase in the value of b* of 1. and 2. frying oil with 0.5 % rosemary essential oil was less. b* Value of the frying oils containing rosemary extract increased compared to b* values of frying oils containing essential oil. b* Value of the frying oil that the essential oil of rosemary added showed less increase than b* value of the frying oil that extract of rosemary. The viscosity values of frying oils containing rosemary extract changed between 30.3 mPas (1. frying oil containing 0.5% extract) and 35.5 mPas (2. frying oil containing 0.5% extract). In addition, free fatty acidity values of frying oils containing essential oil at 0.1, 0.3 and 0.5% levels ranged from 0.160% (1. frying oil containing 0.5% essential oil) to 0.320% (1. frying oil containing 0.3% essential oil). Peroxide values of frying oils containing rosemary extracts were determined between 12.84 meq O2/kg (1. frying oil containing 0.1% extract) and 28.98 meq O2/kg (2. frying oil containing 0.1% extract). Peroxide value of frying made with 0.3 % the rosemary essential oil increased less than that of made with the raw sunflower oil (control) (p < 0.05). Whenever rosemary essential oil and rosemary extract compare, the essential oil seems to be more effective on the peroxide value of the frying oil. The essential oil of rosemary have been effected more from the extracts of rosemary on the oxidative stability of sunflower oil.
Keywords: acidity; antioxidant activity; color; frying; peroxide value; rosemary; sunflower oil.