Optimization of Ultrasound-Assisted Enzymatic Method Extraction of Antioxidant from Malus hupehensis Leaves by Response Surface Methodology

Abstract

In order to study the optimal extraction process of antioxidants from Malus hupehensis leaves, hydroxyl radical scavenging rate was taken as a reference index, and the extraction conditions of antioxidants from Malus hupehensis leaves was studied by response surface optimization ultrasonic-assisted enzymatic method. The results showed that the best process of ultrasonic-assisted enzyme method was 100 W ultrasonic power, liquid to material ratio 17:1 mL∙g−1, ultrasonic time 32 min, cellulase addition 2.6%, enzymatic digestion time 49 min. The hydroxyl radical scavenging rate was 89.9%±0.06% under this condition, the flavonoid content in the extract was 14.01%, the polyphenol content was 8.93%, and the polysaccharide content was 7.65%, compared with the decoction method, reflux method, enzymatic method and ultrasonic method, the active substance content was increased by more than 10%, the DPPH scavenging rate and hydroxyl radical scavenging rate were increased by more than 20%. It's better to extraction of antioxidants from Malus hupehensis leaves by ultrasonic aided enzymatic method.

Keywords

• malus hupehensis leaves
• antioxidant
• ultrasound-assisted enzymatic method
• response surface methodology
• hydroxyl radical scavenging rate