Abstract:

In order to establish a reliable method for determining total flavoniods from tomato, oscillation or sonication for extracting total flavonoids and colorimetric method using aluminum chloride or aluminum nitrate for determining the content of flavonoids were compared. Results indicated that sonication extraction and aluminum chloride method revealed an excellent effect on the determination of total flavonoids from tomato. When rutin was chosen as the standard sample, a good linear relationship was observed in the range of 0.00125－0.0020 mg/ml with a correlation coefficient of 1. The average recovery rate of spiked samples using this method was 95.3%. Moreover, stability, precision and reproducibility of this method were also good. The average content of total flavonoids in tomato was 0.44 mg/g through 75% alcohol and ultrasonic treatment. This method will be widely applied to determine total flavonoids due to its simple operation, excellent accuracy and high reproducibility.

Key words: tomato, total flavonoid, colorimetric method