| The study of papaya seed which is the by-products of papaya industry are mainly concentrated on the oil and extractive in the domestic and overseas. There is scarcely any reports about the papaya seed after decreasing so-call papaya seed dregs.The kinetics of degradation of papaya seed dregs in sub-critical water was investigated by related parameters and the change of morphological which could lead the way of other agricultural by-products such as straw, banana stalk and cornstalk. The antioxidant activity of liquid products of papaya seed dregs after degradation in SCW were assessed by the total antioxidant capacity of FRAP value,reducing power and scavenging free radical of DPPH, ABTS·+ and OH.The antioxidants such as polyphenols, total triterpenes, flavonoids were been determined in liquid products.The effect of extract yield of polyphenols and total triterpenes in papaya seed dregs by different extraction methods had been investigated. The antioxidant components in liquid products were purified by ethyl acetate and n-butyl alcohol.The antioxidant activity and the content of polyphenols and total triterpenes of polarity extracts were been evaluated. The separation and purification of triterpenes in papaya seed were investigated by 5 types of macroporous resins, silicagel, Sephadex-LH-20 and ODS.The components of triterpenes were analyzed by HPLC-MS.The specific studies and results were as follows:1 The change of morphological of papaya seed dregs degradation in SCW were investigated, the results indicated that papaya seed dregs turned into mesh connection, after that, the mesh connection broken up,destroy to ruleless fragment finally.2 The effect of conversion of papaya seed dregs in SCW under different condition were investigated, and the first-order kinetic model were built according to the conversion rate and reaction parameters. The results revealed that the apparent activation energy of papaya seed dregs degradation in SCW is 124.51KJ/mol, the refers to the former factor is 0.2033 min-1.The model has good predictability and accuracy.3 The effect of antioxidant activity of liquid products in different temperature were discussed,excellent antioxidant activity of liquid products showed in 160℃ and 220℃.4 The effect of antioxidant activity of liquid products were probed on time, the results displayed that the liquid products showed the same effect antioxidant activity within 160℃-40min and 220℃-10min. The antioxidants were generated in a short time when the reaction was in high temperature. On the contrary, it would need a long time.5 The content of polyphenols, total triterpenes, flavonoids in liquid products in 160℃-40min and 220℃-10min were investigated. The results indicated that there was scarcely any flavonoids in liquid products,but the polyphenols was 19.78±0.82mg/g within 160℃-40min, the total triterpenes was 55.68±0.32mg/g within 220℃-10min.6 The effect of extract yield of polyphenols and total triterpenes were investigated by SCW,UAE,UMAE and HRE, the results revealed the SCW was superior to others.7 The antioxidant activity of polarity extracts were evaluated, the results revealed that the remarkable antioxidant activity was showed in the extract of ethyl acetate. The concentration of EC50 of scavenging free radical of DPPH and ABTS·+, OH is 0.11,0.14,3.14mg/mL respectively.. And the FRAP value was 638.19±0.90μmol/LFeSO4, the value of reducing power is 16.15±0.92mg/mLVc when the concentration was 1mg/mL.8 The content of polyphenols and total triterpenes in polarity extracts were assayed, the results indicated that ethyl acetate make a difference for enrichment of polyphenols, triterpenes. The content of polyphenols and total triterpenes in polarity extracts were 16.92±0.79g/100g and 37.83±0.98g/100g.9 We have found that the AB-8 resin is one of best material for purification of triterpenoid in papaya seeds by means of comparing the results of static of 5 kinds of resin. The static adsorption of AB-8 for triterpenoid were investigated, the results revealed that the static adsorption isotherm of AB-8 was fitted by the Freundlich equation. We have got the equations after studying the kinetics of static adsorption of AB-8. The adsorption characteristics of dynamic for triterpenoid of AB-8 were investigated, the results indicated that the optimum technology of AB-8 for triterpenoid adsorption was about 3.5mg/mL of triterpenoid,5mL/min velocity. The equation was got by studying dynamic adsorption. The elution curve were revealed centralization peak, excellent symmetry and unconspicuous trailing phenomenon when the elution was with 75% ethanol. The triterpenoid in papaya seeds adsorped by AB-8 were eluted completely by 15 times of column volume. The verification tests showed that 50.03% recovery, and 50.76g/100g purity of triterpenoid in papaya seeds after adsorped by AB-8 resin.10 The content of triterpenoid in Fr4 was 74.98g/100g after separation by silica gel chromatography. We have got five components A,B,C,D and E after separation by Sephadex-LH-20 by eluting of water and methanol(100+0 to 0+100). Those five components were purification by ODS. The ingredients of composition were pomolic acid(A), maslinic acid(B), corosolic acid(C),oleanolic acid(D) and ursolic acid(E). All the compounds of papaya seed above were identified in first time. |
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