Enhanced extraction efficiency of bioactive compounds and antioxidant activity from Hippophae rhamnoides L. by-products using a fast and efficient extraction method

ABSTRACTIn this study, a novel method named high-speed homogenization coupled with ultrasound-assisted extraction (HSH-UAE) followed by high-performance liquid chromatography (HPLC) was employed and investigated for the extraction and determination of main flavonoids rutin, quercetin-3-O-glucoside, quercetin, kaempferol and isorhamnetin from Hippophae rhamnoides L. by-products. Optimal conditions for HSH-UAE, proposed by the single factor and the Box–Behnken design (BBD) tests coupled with response surface methodology (RSM), were 68% ethanol concentration, ultrasonic power 250 W, homogenate speed 9000 rpm, liquid/solid ratio 22 mL/g and extraction time 12 min. The extraction yields of five main flavonoids were significantly improved by HSH-UAE than UAE and high-speed homogenization-assisted extraction (HSHAE). Furthermore, the antioxidant activity of HSH-UAE extracts was assessed by 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays with IC50 value of 0.091 mg/mL and ...