Optimization of microwave and ultrasound-assisted extraction of antioxidant extract from Green marine algae (Chaetomorpha sp) using response surface methodology (RSM)

Chaetomorpha sp is one of the Persian Gulf green algae which can be a marine source of natural antioxidants such as polyphenols. Industrial and economic development of these materials is influenced by effective extraction and application methods. Microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) are novel techniques which have a potential to apply in laboratory with advantages like reduction in extraction time and target compounds deterioration and enhancement in efficiency. In this study, in MAE a central composite design with six replication in central point and 20 experimental runs and a Box-behnken design with six replications at central point and 17 runs were used in order to optimization of antioxidant components extraction from C.sp. Total phenol content, ferric reducing power, DPPH radical scavenging activity and total antioxidant capacity assays were used to evaluate antioxidant activity of the extracts. The results revealed that the highest antioxidant activity in optimum condition in MAE were in following initial factors: power (300, W), time (8, min) and solvent concentration (25%) and in UAE were: time (8, min), temperature (30, ) and TPC was 1.096 and 1.091 mg tannic acid equivalent/g algae in MAE and UAE, respectively. Moreover, the actual experimental values were adjacent to the corresponding predicted values which demonstrated fitness of the employed models and suitability of RSM in extraction parameters optimization. Furthermore, result revealed the green algae has antioxidant activity and can be used as a resource of natural phenols in food and pharmaceutical industries.