Optimization conditions of ultrasound‐assisted extraction of phenolic compounds from orange peels using response surface methodology

Abstract

This study focused on optimizing the extraction conditions of bioactive compounds from orange peels using response surface methodology (RSM) to decrease the number of experimental trials and increase the yield of bioactive compounds. Ultrasonic extraction time, extraction temperature, and ethanol concentration have been optimized. Twenty experimental trials have been carried out to optimize the extraction conditions. The RSM results showed that the extraction temperature and ethanol concentration had a remarkable effect on the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity. The optimal ultrasound-assisted extraction conditions were 44 min extraction time, 50℃ extraction temperature, and 57.7% ethanol concentration. Under these optimal conditions, TPC and TFC were 292.158 µg GAE/g and 191.144 µg catechol/g, respectively, whereas antioxidant activities were 5.199 and 2.96 µg/ml for 2,2-diphenyl-1-picrylhydrazyl and 2,20-azino-bis(3-ethylbenzothiazoline-60-sulfonic acid) diammonium salt, respectively. RSM saves the extraction time and effective for optimizing extraction conditions with the highest efficiency and yield. Novelty impact statement The findings of the current work emphasized usefulness of ultrasound assisted extraction for elevation the extraction efficiency with decreasing the extraction time. The extraction temperature and ethanol concentration are the main effective factors of extraction efficiency. The optimal extraction time was 44 min at 50℃ extraction temperature, and the optimal ethanol concentration was 57.7%. These optimal conditions were giving the highest yield of TPC and TFC that were 292.158 µg GAE/g and 191.144 µg catechol/g. These novel optimized extraction conditions could be useful in different food and pharmaceutical applications.