Antioxidant Activity of Different Tissues of Four Varieties of Tomato Fruit

In order to explore the content, activity and correlation of antioxidant active substances in different tissues in tomato fruits, and utilize the antioxidants efficiently, this study systematically compared the relationship between the content of antioxidants and antioxidant activity in different tissues（peel, pulp and seed） of four varieties of tomato fruits, including two large fruit tomatoes（‘Fengshou 128’‘DRK0568’）, one small fruit tomato（‘Qianxi’）and one laboratory model tomato（‘AC’）. The results showed that the peel was the tissue that had the highest lycopene content. Polyphenols and flavonoids were higher in peel and seeds. Ascorbic acid was found in higher amounts in peel and flesh. Among the four tomato varieties, the contents of total phenols, total flavonoids and ascorbic acid in‘Qianxi’ variety were significantly higher than those of the other three varieties. The 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid（ABTS）,cation free radical scavenging rate of the hydrophilic extract in peel tissue was significantly correlated with the content of total flavonoids, while the ferric reducing ability was significantly correlated with the content of both total phenols and ascorbic acid. The antioxidant activity of lipophilic extracts was significantly correlated with the contents of total phenols, total flavonoids and lycopene. The antioxidant activity of hydrophilic and lipophilic extracts in seed showed a high correlation with the contents of total phenols and total flavonoids. The antioxidant activity of the hydrophilic extracts in flesh was highly correlated with the ascorbic acid content, while the antioxidant activity of lipophilic extracts showed the highest correlation with the lycopene content. In conclusion, the peel and seeds of tomato contained rich antioxidant active components and showed relatively high antioxidant capacity. This study can provide guidance for the efficient utilization of antioxidant active substances in tomato and a healthy diet.