Abstract: Process technological conditions for obtaining fucoidan from Sargassum fusiforme (FSF) via ultrasonic assisted enzymatic hydrolysis with cellulase was optimized by orthogonal experiments.Factors that affect the yield of FSF,including solvent pH value,enzyme dosage,reaction temperature,cellulase hydrolysis time,and ultrasonic time were investigated.The better extraction conditions were as following:pH,4.5;enzyme dosage,1% of the mass of the raw material;reaction temperature,40 ℃;cellulase hydrolysis time,2 h;ultrasonic time,15 min;and material-liquid ratio,1∶10 (g∶mL).Under such conditions,the yield of FSF achieves 8.50%,and RSD=2.74%.The hygroscopicity (8 h) of crude extract of fucoidan from Sargassum fusiforme (CEFSF) is better than that of glycerin,butanediol,and sodium alginate.The moisture retention capacity of 1% CEFSF aqueous solution (mass fraction) is better than 1% butanediol (mass fraction) and 1% sodium alginate (mass fraction),which is equivalent to that of 5% glycerin (mass fraction),under relative humidity of 43% and 81%.The results of skin moisture content and transepidermal water loss rate show that:5% CEFSF aqueous solution (mass fraction) shows a good moisturizing effect.

Key words: additive of skin-care cosmetics, fucoidan from Sargassum fusiforme, orthogonal test, moisture, skin moisture content, transepidermal water loss rate