STABILIZATION OF CANOLA OIL WITH FLAVONOIDS

The antioxidant activity of a number of flavonoids in refined-bleached (RB) canola (double-zero rapeseed) oil is compared with that of commo nly used synthetic antioxidants, namely, butylated hydroxyanisole, BHA , and butylated hydroxytoluene, BHT. The study was carried out over a thirteen-day period at 65 degrees C and progression of oxidation was f ollowed by monitoring weight gain and peroxide and 2-thiobarbituric ac id (TBA) values. Among the flavonoids tested, myricetin, (-)epicatechi n, naringin, rutin, morin, and quercetin were superior to BHA and BHT in inhibiting oil oxidation. The addition of myricetin, the most activ e flavonoid tested, delayed the induction period of lipid oxidation by up to fifteen days and also inhibited the formation of oxidation prod ucts by 69% during this period. Natural flavonoids may therefore have potential application for the stabilization of canola oil.