Abstract: In this study,kelp was used as the main raw material for producing fermented beverage enriched high-concentration laminaria-polysaccharide by lactic acid bacteria fermentation.The enzymolysis conditions of the kelp and factors which influenced the extraction yield of total crude laminaria polysaccharides were studied.The acid production and the unpleasant odour removal effect were studied,and the formulation of fermented beverage was determined.The results showed that the optimum extracting conditions of the laminaria polysaccharides were that the ratio of the compound enzyme to the kelp power 1.5:100,and enzymolyzing 6 h at the condition of pH6.0 and 50 ℃.On these conditions,the extraction yield of total crude laminaria polysaccharides could be up to 10.89%.The optimum proportion of the compound enzyme(cellulose,pectinase and protease)is 2:1:2.The optimum conditions for fermented laminaria polysaccharide beverage are that whey powder 0.5%,sucrose 7%,lactic acid bacteria 1 mg/100 ml,and fermented at 40 ℃ for 24 h.On these conditions,the yield of lactic acid is about 0.7%.

Key words: laminaria-polysaccharide, compound enzyme, lactic acid fermentation, lactic acid beverage