Background: Flavonoids are natural bioactive constituents in many plants. Fisetin (3,3′,4′,7-tetrahydroxyflavone), is a known key flavonoid found naturally in tomatoes, it has gathered interest worldwide for its potential prevention of chronic diseases.

Aim: Using simple and low-cost methods for the extraction, identification, and measurement of the concentration of naturally occurring fisetin in tomatoes.

Method: Two solvent mixtures were used for the extraction of fisetin, methanol/water (80:20) v/v and ethanol/water (50:50) v/v, followed by the measurement the total contents of phenols and flavonoids, in addition to the analysis of fisetin via thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC).

Results: The contents in the methanol extract (ME) and ethanol extract (EE) were 5.15g and 2.65g, respectively. Although there was no significant difference (p>0.05) in total phenolic content between the two extracts, total flavonoid content was found to be significantly increased in EE (p≤0.05). The presence of fisetin in the sample was confirmed by TLC, while HPLC showed higher values in EE (4.40 mg/g) than in ME (3.18 mg/g).

Conclusion: Ethanol is a more effective solvent for fisetin extraction, providing a simple and low-cost approach for recovering a good amount of fisetin from tomato.