Optimization extraction technology and preliminary characterization of fucoidan from Laminaria japonica

Using the high pressure homogeneous combined with composite enzyme extracted fucoidan from Laminaria japonica. With the fucoidan extraction rate as a measure indicator, alga/water ratio, enzyme dosage, pH were optimized by using response surface methodology based on single factor experiments. Then the optimized condition obtained by Box-Behnken design and response surface methodology were as follows:water ratio 1∶35, pH5.32, enzyme dosage 2.5%. Under this condition, the extraction rate was 14.53%±0.05%.At last, molecular weight of fucoidan were 639, 248, 79 ku, determined by HPGFC;IC-PAD analysis showed monosaccharides constituents in the fucoidan were fucose, , rhamnose, arabinose, galactose, glucose, xylose, mannose. And their contents were 42.81%, 1.95%, 1.57%, 31.35%, 3.30%, 5.56%, 13.30% respectively.