Process Optimization for Ultrasonic-Assisted Enzymatic Extraction of Polyphenols from Grape Pomace

Taking Cabernet Sauvignon grape pomace as the research material,polyphenols were extracted by ultrasonic-assisted enzymatic method. Based on the influence of ultrasonic treatment time,ultrasonic power,enzymatic hydrolysis pH and enzymatic hydrolysis temperature on the yied of grape marc polyphenols were discussed,the optimal conditions of ultrasonic-assisted enzymatic extraction of polyphenols from grape pomace were determined using the orthogonal experiments. The results showed that the primary and secondary factors affecting polyphenols yield were ultrasonic time > enzymatic hydrolysis temperature > ultrasonic power > enzymatic hydrolysis pH. The optimal process parameters identified were as follows:ultrasonic time was 15 minutes,ultrasonic power was 400 W,enzymatic hydrolysis pH was 6.0,enzymatic hydrolysis temperature was 60 ℃,under these process conditions,the highest polyphenol yield could reach 1.493%±0.0068%. The process is less expensive,simple and ripe,stable and feasible,and since it is based on the environmentally friendly extraction solvent,it may provide a valuable alternative to the conventional extraction methods.