Extraction process and antioxidative activities of thebrowning products from Musa paradisiaca flesh

Based on single experiments，with the yield of total anthraquinones as index，ethanol concentration，extraction time，ratio of material to liquid，extraction temperature were selected as factors，the processing parametersfor extraction of browning products were optimized by L16（45）orthogonal design. In addition，the antioxidative activitiesof the browning products were evaluated in vitro by scavenging capability of hydroxyl free radical（OH·），1，1-diphenyl-2-picrylhydrazyl free radical（DPPH·），2，2'-Azinobis-（3-ethylbenzthiazoline-6-sulphonate）free radical（ABTS·+）and superoxide anion free radical（O2-·）. The results showed that the optimal condition was as follows：75% of ethanolconcentration，9 h of extraction time，1∶4.5 g/mL of ratio of material to liquid，50℃ of extracting temperature. Under thiscondition，the yield of total anthraquinones was 0.05%. The half-scavenging concentration（IC50）values of the browningproducts against OH·，DPPH·，ABTS·+ and O2-· radicals were 0.0044，0.0022，0.0011 and 0.0001 mg/mL, respectively.