Antioxidant activity of selected Indian spices

Spices and vegetables posses antioxidant activity that can be applied for p reservation of lipids and reduce lipid peroxidation in biological systems. The potential antioxidant activities of selected spices extracts (water and alcohol 1:1) were investigated on enzymatic lipid peroxidation. Water and alcoholic extract (1:1) of commonly used spices (garlic, ginger, onion, min t, cloves, cinnamon and pepper) dose-dependently inhibited oxidation of fat ty acid, linoleic acid in presence df soybean lipoxygenase. Among the spice s tested, cloves exhibited highest while onion showed least antioxidant act ivity. The relative antioxidant activities decreased in the order of cloves , cinnamon, pepper, ginger, garlic, mint and onion. Spice mix namely ginger , onion and garlic; onion and ginger; ginger and garlic showed cumulative i nhibition of lipid peroxidation thus exhibiting their synergistic antioxida nt activity. The antioxidant activity of spice extracts were retained even after bioling for 30 min at 100 degrees C, indicating that the spice consti tuents were resistant to thermal denaturation. The antioxidant activity of these dietary spices suggest that in addition to imparting flavor to the fo od, they possess potential health benefits by inhibiting the lipid peroxida tion. (C) 2000 Harcourt Publishers Ltd.