Studies On β-carotene And Polysaccharides From Dunaliella Salina

The Dunaliella Salina is a useful sources of β-carotene , which can also accumulate hydrophilic carbohydrates and proteins. The extraction and isolation of β-carotene and polysaccharides from D. salina were studied in this paper.In this paper, the extract method of 6-Carotene from Dunaliella salina by Supercritical CO₂ was studied. The effects of influencing factors such as extraction pressure, temperature, time and flow rate of CO₂ on the extraction ratio of B - carotene from Dunaliella salina were discussed respectively. The optimal extraction condition by supercritical CO₂ were determined: extraction pressure was 30 MPa, extraction temperature was 45℃, flow rate of CO₂ was 10L/H , extraction time was 6 hours. The result showed that the yield of supercritical CO₂ extraction was 95.09%. It was higher than the yield of solution extraction (90.17%).The result showed that the extraction pressure and extraction temperature had significantly effects on the contents of B -carotene isomers. The supercritical CO₂ extraction were composed of 82.0% cis-carotene and 18.0% all-trans-β-carotene. The solution extraction were composed of 48. 8% cis- carotene and 51. 2% all-trans-β-carotene. It shows supercritical CO₂ extraction is superior to the solution extraction for B-Carotene isomers.The extraction process of the polysaccharides from D. salina was also studied. The extraction process was analysed by the orthogonal experimental design. The proteins were removed by enzymatic hydrolysis. The optimum extraction condition is 16-volumn water was add to the D. salina pellet, pH was adjusted to 9 with 40% NaOH, and extraction was performed at 100℃ for 10 hours. The polysaccharides from D. salina. was deproteinated by neutral protease. The content of polysaccharide was 29.01%. The result showed that this extraction process is the effective to the isolation of polysaccharides from D. salina. Polysaccharides from D. Salina. was sulfated proteoglycan of containing uronic acid .The Polysaccharides from D. Salina was further purified by the DEAE-cellulose and Sepharose 4B. Three components named PDS₁,PDS₂,PDS₃were purified by DEAE-cellulose chromatography. Each of the three components was separated into two components by Sepharose 4B chromatography, then six components named PDSn> PDS^ PDS2^ PDS22n PDS3i% PDSS2 were isolated from D. salina. in the end.The six components' some properties were studied. The IR analysing results about them showed that they had the sulfate and carboxyl groups et. Their molecular weights> viscosities and specific rotations were estimated.Inhibition rates of these polysaccharides on the P388 were determined. The conclusion was that PDSi^ PDS12> PDS2in PDS3i showed some inhibitory effects on P388.