Extraction Conditions Optimization and Antioxidant Capacity Research of Polyphenols from Inonotus obliquus

Polyphenols were extracted by ultrasonic-microwave co-extraction with sclerotia of Inonotus obliquus．Extraction conditions of polyphenols from Inonotus obliquus were optimized by single factor and multi-factor experiments, and antioxidant capacity of polyphenols was determined．Results showed that optimal extraction conditions were as follows: ethanol volume fraction of 50%, solid-liquid ratio of 1∶60, microwave power of 400 W, ultrasonic power of 350 W and extraction time of 240 s．Under these conditions, extraction rate of polyphenols was 2.943%．Polyphenols extracted by this method had good antioxidant capacity．The IC₅₀ of DPPH free radical scavenging was 9.03 μg/mL, and the IC₅₀ of hydroxyl free radical scavenging was 2.03 mg/mL．This method is a practical, effective and rapid method for the extraction of polyphenols from Inonotus obliquus．