Optimization of acidification process conditions for preparing ellagic acid from pomegranate peel by response surface methodology

This paper examines the optimum acidification process conditions for preparing ellagic acid from pomegranate peel by response surface methodology.The effects of the concentration of sulfuric acid, acidification time and temperature on the yield of ellagic acid were studied based on polyphenols extract conversion rate. According to the single factor experiments, the optimum acidification process of ellagic acid was determined through Box-Benhnken central composite design and response surface methodology. The results showed that when the pomegranate peel polyphenols extract conversion rate reached up to 86.38%, the acidification process conditions, i.e. the optimal ones were as follows:sulfuric acid of 0.83mol /L, the acidification time of 5h and acidification temperature at 105℃.And ellagic acid samples were obtained with anhydrous methanol heat reflux extraction of 4 times. A quadratic equation model for the preparation of ellagic acid by the pomegranate peel polyphenols extract acidification was set up and it played a good predicted role.