M. R. KIM1, E. J. Son1, and K. B. Song2. (1) Department of Food Science & Nutrition, Chungnam National University, Taejon, 305-764, South Korea, (2) Dept. of Food Science & Technology, Chungnam National Univ., College of Agriculture & Life Sciences, 220 Gung-dong, Yuseong-gu, Daejon, 305-764, South Korea
High consumption of vegetables has been associated with a lowered incidence of degenerative diseases. These protective effects are considered to be related to the various antioxidants contained in them. Many of the natural antioxidants, especially flavonoids, seem to be very important in the prevention of these diseases. However, information on the relationship between antioxidant activity and phenolic content is not available. The objective of this study is to determine the contents of total phenolics in salad vegetables and to explore relationship between phenolic content and antioxidant activity.
The antioxidant activities and total phenolics of 48 salad vegetables were determined. The total phenolic content, determined according to the Folin-Ciocalteu method, and Antioxidant activities of methanolic extract of salad vegetables was evaluated by measuring DPPH free radical scavenging activity, and TBARS (thiobarbituric acid-reactive substances) in ox brain homogenates subjected to Fe2+-mediated lipid peroxidation.
The methanolic extract of salad vegetables at 1mg/ml showed 50-70 % inhibition of free radical scavenging activity, and 50-90% inhibition of lipid peroxidation in brain membrane. Of these salad vegetable extracts examined, those with more phenol content showed a lower IC50 value, which shows higher antioxidant activities. The correlation coefficient between total phenolics and antioxidative activities was statistically significant.
On the basis of these results, it is suggested that the intake of salad vegetable rich in phenolics would be beneficial in improving degenerative disease caused by oxidative stress.
Session 33F, Nutraceuticals & Functional Foods: Antioxidants and phytochemical analysis