The effect of rosemary extract (Rosemarinus officinalis L.), a natural antioxidant, on stability of fryingoil during heat treatment and on sensorial quality of fried potato was studied.
A mixture of soybean and sunflower oils in an equal proportions and containing 0.08% of rosemary extract was evaluated forthermo-oxidation at 180◦C for 30 h.
This evaluation was carried out comparatively to an oil mixture with out antioxidant.
Results showed a significant difference (p < 0.05) between oils according to themeasured parameters especially at the end of treatment.
The addition of the rosemary extract in the mixture of soybean and sunflower oil reduce the peroxide value by 38% after 30 h of heating.
This oilresists to oxidation and conserves the higher amount of unsaturated fatty acids even after 30 h of heating.The evolution of saturated fatty acid composition is estimated at 5.5% and 25% in the oil with and with out extract, respectively, at the end of the heating treatment.
Sensorial analysis carried out showed that the fried potato prepared in oil with rosemary extract had the best crispiness and taste until the fifteen frying.
The oil with rosemary extract showed an enhanced stability and therefore a best quality comparedto the oil without rosemary extract.