| Fucoxanthin is a kind of characteristic pigment of brown alga, which is considered to havephysiological funcations including anti-cancer, anti-aging, weight control and regulating bloodglucose level, etc. So far, the researches mainly focused on fucoxanthin in Laminaria japonicaand Undaria pinnatifida, However, there is little report on fucoxanthin in Hizikia fusiform.Hizikia fusiform, which belongs to the Sargassaceae of Phaeophyta, is rich in polysaccharide,protein, fucosterol and other functional substances, and it is specified as Chinese medicineseaweed by Chinese pharmacopoeia. Hizikia fusiform distributes widely along the coast of China,and the larger size culture station has been established in Zhejiang Province.Taking Hizikia fusiform from Dongtou Zhejiang as raw material, a detection method forfucoxanthin by High Performance Liquid Chromatography(HPLC)was established. Orthogonalor response surface Box-Behnken experimental design based on single-factor test was used forprocess optimization of solvent extraction, enzymatic extraction, ultrasonic-assisted extractionand supercritical CO2extraction respectively. Macroporous resin was selected for purifyingfucoxanthin extracted by solvent extraction.The effects of light, temperature, pH, oxidants andanti-oxidants on fucoxanthin were investigated by UV spectrophotometry. Differentextracorporal antioxidant systems were applied for preliminary study of the antioxidant offucoxanthin. The present study could provide theoretical basis and methods reference for theindustrial production of fucoxanthin and could lay the foundation for thorough study ofantioxidant of fucoxanthin. The main conclusions are listed as follows:(1) The HPLC detection method of fucoxanthin were established, the detection conditionswere column Hypersil ODS C-18(Thermo,4.6mm×250mm×5μm),450nm of UWD,30°C ofcolumn temperature, methanol/acetonitrile/0.1%ammonium acetate solution (V/V/V75/15/10)ofmobile phase,1mL/min of flow rate and20μL of injection volume. The average recovery rateof this method was97.94%, and its precision and stability were good. So it can be used forqualitative and quantitative detection of fucoxanthin.(2) The technological conditions of different methods for extracting fucoxanthin wereoptimized, For solvent extraction,90%ethanol and acetone volume ratio of3:1was extractionsolvent, the ratio of solvent to material was40:1, extraction was conducted for two times at65°C,80min for each time.The extraction efficiency was1.067mg/g, and the purity was 1.302%; For enzymatic extraction, cellulose dosage was120U/g, reaction temperature was45°C, reaction time was11h.The extraction efficiency was0.958mg/g,and the purity was1.419%; For ultrasonic-assisted extraction, ultrasonic time was22min, power was530W andthe ratio of solvent to material was40mL/g.The extraction efficiency was1.202mg/gand thepurity was2.02%; For supercritical CO2extraction, temperature was55°C, pressure was315bar,time was2.5h.The extraction efficiency was0.621mg/g and the purity was7.36%. Theextraction efficiency of fucoxanthin extracted by ultrasonic-assisted extraction was higher thanthe other three methods, and the purity of fucoxanthin extracted by supercritical CO2extractionwas higher than the other three methods. Suitable production process technology could bechosed depenging on the needs and production conditions.(3) Eight macroporous resins were compared for the adsorption and desorption tofucoxanthin and chlorophyll in extraction solution of fucoxanthin. D101was selected fordynamic purification. With1.6BV/h of flow rate, the concentration of chlorophyll was0.5157mg/mL, the concentration of fucoxanthin was0.1499mg/mL. The maximum adsorbance was12BV. Fucoxanthin was eluted with80%ethanol11BV. The eluted chlorophyll with acetone4BV,D101resin should be retextured after seven time use. The average purity of fucoxanthin was8.57%, and it was5.6times higher than previous purification. The average recovery rate was83.29%. Fucoxanthin and chlorophyll can be obtained by this purification process, so it was acost-effective method, and it was easy to operate. Therefore, it may be suitable for industrialproduction. However, D101absorbed fucoxanthin and chlorophyll. The consequence was thatfucoxanthin and chlorophyll can not be separated completely. In addition, a small amount of oilysubstance was present.Thus, the purity of fucoxanthin did not achieve the desired value.(4) Effects of light, temperature, pH, oxidant and anti-oxidant on fucoxanthin wereinvestigated. Fucoxanthin was unstable with light and high temperature. It was sensitive tostrong acid or alkali, and was easily decomposed by oxidants. However it was relatively stablewith anti-oxidant present. Therefore, the storage and transportation of fucoxanthin should beavoiding light, high temperature and touching with strong acid or alkali for a long time.Anti-oxidants can be added appropriately.(5) The anti-oxidant activities of fucoxanthin were studied. The results showed that thereducing power of fucoxanthin was lower than VC and VE. Whereas it had strong scavenging ability to DPPH·、·OH、O-2·free radicals and H2O2. The scavenging ability to·OH, O-2·offucoxanthin also was higher than VC. In addition, the resisting lipid peroxidation activity offucoxanthin was significantly stronger than that of VC. The results suggested that fucoxanthinwas in strong inoxidizability, and thus it can be served as an anti-oxidant incorporated to foods,medicines, health products and cosmetics.The test took Hizikia fusiform as raw material for the first time, studied extractiontechnique, purification technology, stability and antioxidation of fucoxanthin systematically, andit solve the problems of onefold source, low extraction efficiency, and difficult conservation offucoxanthin, and enrich the research of bioactivity of fucoxanthin.. The test offers new source,reference for methods, and scientific proof for the industrialization production of fucoxanthin,and improves the comprehensive value of Hizikia fusiform. |
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