Optimization of phenolic compound extraction from purple basil leaf via different methods

Ocimum basilicum L., a member of the Lamiaceae family, known as reyhan or red basil in our country, has been subjected to many researches in recent years due to its high content of bioactive components with many pharmacological effects. In this study, extraction optimization of phenolic compounds from the purple basil leaf was carried out using different extraction methods. For this purpose, conventional solvent extraction (CSE), ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE) techniques were used and optimum extraction conditions for each method were determined by using Response Surface Methodology (RSM). Extraction temperature (30-60 °C) and time (10-30 min) for CSE and UAE were determined as model parameters. Power level (300-600 W) and extraction time (1-3 min) were chosen as model parameters for MAE. For each method, the effect of the determined parameters on the total phenolic, total flavonoid, total anthocyanin compound and antioxidant capacity amounts were examined. Given the data obtained under optimised conditions, it was observed that the most efficient method is microwave assisted extraction. This is followed by ultrasound assisted extractions. The maximum total phenolic, total flavonoid, total anthocyanin and antioxidant capacity (CUPRAC) concentrations in the optimum conditions (591.83 W and 2.98 min) for MAE were 62.99 mg GAE/g sample, 21.80 mg CAE/g sample, 3462.93 mg Cy-3-glu/kg sample and 214.62 mg TEAC/g sample respectively. This study suggested that extraction yield of the phenolic compounds of purple basil leaf could be increased by using MAE method. Also, these findings illustrate that extraction of bioactive compounds using MAE method saves time.