Antioxidant activity of some herbal extracts in rapeseed and sunflower oils

Antioxidant and prooxidant properties of natural antioxidant concentrates with high contents. of flavonoids, carotenoids and phenolic acids were studied. Antioxidant concentrates from marigold (Calendula officinalis L.), basil (Ocimum basilicum. L.), self-heal (Prunella vulgaris L.) and wool mullein (Verbascum densiflorum L.) were added to sunflower and rapeseed oil, respectively, at concentrations ranging from 2 mg.kg(-1) to 200 mg.kg(-1) oil. The Rancimat assay was used for the optimization of antioxidant doses of individual plant concentrates. The most effective antioxidant in both sunflower and rapeseed oil was the marigold concentrate (optimal dose was 10 mg.kg(-1) and 30 mg.kg(-1), respectively). Basil concentrate possessed an antioxidative effect comparable with the antioxidative effect of marigold concentrate - the optimal dose was 2 mg.kg(-1).