Study On The Extraction, Isolation And Structure Analysis Of Pigment From Passiflora Edulis Skin

Passiflora edulis is an important kind of tropical fruits in china. Passiflora edulisskin is the main by-product of the juice industry. In this paper, extraction, purification,identification and antioxidation effect of Passiflora edulis skin pigment (PESP) werestudied. The result provided scientific basis for the further exploitation. The resultsare as follows:Comparing different testing methods, the results showed that pH-differentialspectrophotometry has high accuracy in the determination of anthocyanin content.Solvent extraction method was used to extract PESP. Among the UniformExperimental Design,86%aqueous ethanol containing0.054%HCl and0.1%citricacid was the best extraction solvent. Through the design of quadratic rotationalcombination test and multiple regression analysis, the regression model related toextraction yield of PESP indicated that the optimized condition of the responsesurface model (RSM) was adjusted as30℃,110min,1:37to practicalproduction.Under this condition,the extraction rate of PESP was0.395mg/g.In order to determine the optimum macroporous resin and condition forpurifying pigments extracted from Passiflora edulis skin, the adsorption anddesorption properties of different resins were studied. The results showed thatmacroporous resin HP-20is favorable in purification of the PESP：the optimumcondition of static adsorption was40℃,pH4.0, and the best desorption solvent was90%ethonal(pH3.5).The optimizd parameters of dynamic adsorption desorption werechosen as follow: velocity of pigment solution flow4.5BV/h, pigment solution18.176μg/mL,the volume and velocity of desorption solvent6BV,3BV/h.After a series of column chromatography separation, including HP-20macroporous resin, polyamide and sephadex LH-20, main three types of anthocyaninmomomer were tentatively identified by the method of HPLC-MS. The three mainanthocynins may be cyaniding-3-glucoside, petunidin-3-glucoside andMalvidin-3-glucoside. The antioxidation ability of PESP was studied. The result showed that totalantioxidation ability of PESP was804.1U/mg, scavenging superoxide anion ability ofPESP was51.9U/mg, scavenging hydroxyl radical ability of PESP was14400U/mg,scavenging DPPH radical ability of PESP was86.5%.