Application of the Static Headspace Method as a Tool for Rapid Control of Fennel Seed Tea Vapors

Background: In recent years, there have been tensions surrounding the accessibility of drugs at pharmacies. This situation has led people to turn to alternative medicine with increased use of plants as medicines. Nevertheless, a good knowledge of the plant's chemical composition is necessary for its proper use due to the presence of toxic products. Objective: The research objectives are to expand a novel use of the static headspace technique to control the chemical composition of the vapor of fennel seed tea (Foeniculum vulgare Mill.) and also constitute an attempt to develop a targeted qualitative analytical method for quality control and safety assurance of a consumer product. Methods: This study qualitatively investigated the amount of estragole in fennel herbal tea vapour by successful rehabilitation of the static headspace gas chromatography/mass spectrometry method. In addition, an analysis is conducted on the total phenolic and flavonoid content in both tea and methanol extract. Antioxidant activities of all extracts were measured and compared to Gallic acid. Results: The fennel seed tea showed total phenolic and flavonoid contents at 187.7 ± 17.1 GAE/100 g and 133.8 ± 9.07 mg CE/100 g, respectively. Fennel seeds tea exhibited good DPPH anti-radical action with an IC50 of 92.38 ± 10.64 mg/g. Even though studies on the total phenols, flavonoid contents, and antioxidant activity of this herbal tea have all yielded positive outcomes, the application of the static headspace method combined with gas chromatography and mass spectrometry indicated the presence of estragole at 37.63 ± 3.77%. This compound was found at 80.67 ± 0.29% in the essential oil. Conclusion: The application of this method has made it possible to reduce the handling time by eliminating the extraction step and solvent use. The presence of estragole at an alarming level makes it clear that employing plants as medicines must be regulated.