A comparison of the performance of conventional and eco-friendly extraction methods in the evaluation of total phenolics, antioxidant activity, and chemical composition of anise.

In this work, the essential oil of seeds was obtained by six different extraction methods. In the chemical composition analysis, 4, 6, 4, 1, 20, and 8 compounds were detected in the extracts obtained by Soxhlet, Ultrasonic-assisted (UAE), hydrodistillation using Clevenger apparatus (HDC), subcritical water extraction (SWE), supercritical carbon dioxide extraction (ScCO) using three solvents (methanol (ScCO-Met), ethanol (ScCO-Et), and hexane (ScCO-H)) and supercritical 1,1,1,2-tetrafluoroethane (ScR134a) methods, respectively. Also, the performances of the applied methods were compared by analysing the total phenolic content (TPC) and antioxidant activity of the extracts. Anethole was the main component of all extracts obtained by SWE (94.5%) and Soxhlet (94.5%) methods, respectively. Also, TPC values were the highest (508.5 mg GAE/100 g kb) in ScR134a extract and the lowest (27.77 mg GAE/100 g kb) in HDC extracts. The antioxidant capacity was found to be the highest in ScCO-H (IC = 1.58 mg/mL) and the lowest in Soxhlet extracts (IC = 0.07 mg/mL). The results showed the great effectiveness of eco-friendly extraction SWE, ScCO-Et, and ScR134a methods.