Improved frying stability of canola oil blended with palm olein and virgin olive oils as affected by bene kernel oil and its unsaponifiable matter

摘要

Bene kernel oil and its unsaponifiable matter fraction, which have been known to be very effective natural sources of antioxidative compounds, were used to improve the frying stability of canola oil blended with palm olein and virgin olive oils (75: 15: 10) at 180 degrees C. The powerful synthetic antioxidant tert-butylhydroquinone (TBHQ, 100 mg/kg) was employed for the comparative purposes. Frying stability of the oil samples was measured based on the variations of conjugated diene value, carbonyl value, total polar compounds content, thermo-oxidative and hydrolytic components, and the content of total tocopherols. In the presence of bene kernel oil and its unsaponifiable matter fraction the conjugated diene (194-224 vs. 244%) and carbonyl values decreased significantly (183-265 vs. 358%). Furthermore, the antioxidative additives showed more inhibitory effect on thermo-oxidative reactions than hydrolytic ones during the frying process. The best frying performance was obtained by using 1000 mg/kg of bene kernel oil and 100 mg/kg of the unsaponifiable matter fraction of bene kernel oil and TBHQ.