The pitaya peel powder was mixed with 50%ethanol solution at a ratio of 1:10(w/v)for 24 h to obtain the pitaya peel ethanol extract(E).The extract was further fractionated with supercritical carbon dioxide(SC-CO_(2))u...The pitaya peel powder was mixed with 50%ethanol solution at a ratio of 1:10(w/v)for 24 h to obtain the pitaya peel ethanol extract(E).The extract was further fractionated with supercritical carbon dioxide(SC-CO_(2))under the operating conditions:temperature 40℃ and pressure of 30,25,20 or 10 MPa into R,F1,F2 or F3 fractions,respectively.Our results confirmed SC-CO_(2)fractionation significantly influenced the distribution of phenolic compounds,polysaccharides and betalains in fractions and thus affected their physico-chemical properties.Bioactive compounds majorly distributed in F1;consequently,DPPH and ABTS radicals scavenging activities of F1 are higher than those of other fractions.The IC_(50)values of DPPH and ABTS scavenging ability were 0.78 mg/mL and 0.69 mg/mL for F1 fraction,respectively.Linear structure model analysis showed that the scavenging activities of the both free radicals were positively related to phenolic compounds and polysaccharide components.The strong red-orange color spectrum of E was simultaneously fractionated into the red-orange color F1,the bright red color of F2 and F3 and the vivid orange color of R.展开更多
基金support(MOST 108-2221-E415-014)from the Ministry of Science and Technology,Taiwan,ROC is gratefully acknowledged。
文摘The pitaya peel powder was mixed with 50%ethanol solution at a ratio of 1:10(w/v)for 24 h to obtain the pitaya peel ethanol extract(E).The extract was further fractionated with supercritical carbon dioxide(SC-CO_(2))under the operating conditions:temperature 40℃ and pressure of 30,25,20 or 10 MPa into R,F1,F2 or F3 fractions,respectively.Our results confirmed SC-CO_(2)fractionation significantly influenced the distribution of phenolic compounds,polysaccharides and betalains in fractions and thus affected their physico-chemical properties.Bioactive compounds majorly distributed in F1;consequently,DPPH and ABTS radicals scavenging activities of F1 are higher than those of other fractions.The IC_(50)values of DPPH and ABTS scavenging ability were 0.78 mg/mL and 0.69 mg/mL for F1 fraction,respectively.Linear structure model analysis showed that the scavenging activities of the both free radicals were positively related to phenolic compounds and polysaccharide components.The strong red-orange color spectrum of E was simultaneously fractionated into the red-orange color F1,the bright red color of F2 and F3 and the vivid orange color of R.
