Study on ultrasonic extraction of total phenol from edible rose and antioxidant activity of macroporous resin before and after purification

Rosa chinensis ‘An Ning Ba Jie'as the raw material, the extraction process of polyphenol and the antioxidant activity before and after purification were studied. The extraction temperature were identified as main factor that influence extraction efficiency.The optimum conditions for the ultrasonic extraction of polyphenols from rose were found to be with 70%ethanol at solid-to-liquid ratio 1 ∶ 25 ( g/m L) for 40 min with ultrasonic temperature 40 ℃ with extraction three times. Under these conditions, the extraction of total phenol was 93.81 mg/g. The XAD-7 resin was found to be the ideal resin for the purification of phenolics from rose by comparing the static adsorption and analytical properties of nine resins.Before purification of DPPH and ABTS free radical scavenging IC50 values were 209.27 μg/m L and 505.67 μg/m L, after purification, they were96.30 μg/m L and 378.09 μg/m L, respectively.The results showed that rose polyphenols could enhance their antioxidant activity after purification by XAD-7 macroporous resin.