Optimization of bioactive compounds extraction process from bene hull (Pistacia atlantica) using subcritical water by response surface methodology

Bene hull (Pistacia atlantica) contains noticeable antioxidant components. The aim of this study was to obtain a set of optimum conditions for bioactive compounds extraction process from bene hull using subcritical water by response surface methodology (RSM). Temperature (110 – 200 °C), processing time (30-60 minutes) and water to bene hull ratio (10:1-50:1) were the factors investigated. Experimental design was performed using central composite face centered design (CCFD) and RSM. The optimal conditions for maximizing antioxidant activity were at 196.81 °C for 52.57 min and the ratio of 43.61:1 for water to bene hull. Under these conditions, the amount of polyphenolic compounds, reduction power according to EC50 and DPPH free radical scavenging activity according to EC50 were predicted to be 2284 mg gallic acid / 100 g bene hull, 0.2002 mg /ml and 0.6284 mg/ ml, respectively. Extraction and analysis of extracts in optimal point support these results.