Study on Antioxidant Activities of Two Varieties of Onion Extract

The antioxidant activities of two varieties of onion extract were studied and evaluated by determining the reducing capacity,antioxidant activity in soybean oil and scavenging effects on hydroxyl radical.The results showed that onion extracts extracted in different temperature had different reducing capacity which increased with the increasing of extraction temperature;different variety of onion were also different in antioxidant activities:purple onion extract had stronger reducing capacity than yellow onion;similar results were observed in scavenging effects on hydroxyl radical and antioxidant activity in soybean oil;the onion extracts were all better than 0.5g/L ascorbic acid in reducing capacity and scavenging effects on hydroxyl radical.