evaluation of the antioxidant potential of fennel seed extract as compared to the synthetic antioxidants in margarine under accelerated storage condition

the oxidative stability of margarine supplemented with different concentrations of fennel (foeniculum vulgare) seed extract (fse) was compared to the synthetic antioxidants; butylated hydroxyanisole (bha) and butylated hydroxytoluene (bht) at legal concentrations. the experiment was carried out under accelerated storage conditions for 4 weeks employing peroxide value (pv), p-anisidine value (av) and totox value at constant time intervals of 7 days. the induction period measuring the stability of the oil was determined by metrohm rancimat. the extraction yield from fennel seeds was 12.92% w/w. it was concluded that the antioxidant effeciency of the extract was concentration dependent and by increasing the concentration from 80 to 100 mg kg-1, the antioxidant activity of the extract was increased. after 4 weeks of storage at 90°c, margarine containing 100 mgkg-1 fse showed lower peroxide values, p-anisidine values and totox values and higher induction periods as compared to the synthetic antioxidants, bha, bht and the control. these results illustrate that fse might be used as a potential source of natural antioxidant to retard lipid oxidation in margarine.