Study Of High-quality Acaudina Molpadioides Polysaccharide Preparation Technology

Sea cucumber is traditional valuable aquatic product in China, and it possesses aseries of biological activities. The sea cucumber polysaccharide is important efficacycomposition of sea cucumber body wall. Sea cucumber polysaccharide extractionlacked systematic research, and the quality of polysaccharide extracted by traditionaltechnology was poor. Acaudina molpadioides is domestic low-value sea cucumber.Acaudina molpadioides polysaccharide extraction would provide effective way of seacucumber value-increment.Low-value sea cucumber Acaudina molpadioides was selected as raw material,polysaccharide of body wall was extracted. Determination method of protein contentof polysaccharide was determined. Folin-phenol method could be accurate and easy todeterminate protein content of Acaudina molpadioides polysaccharide. Detectionmethod of turbidity was determined, and turbidity detection wavelength was470nm,Chrominance detection method was determined, and chrominance detectionwavelength was460nm.Polysaccharide was prepared using enzymatic combination ultrafiltrationtechnology. Through screening the enzyme type, the single factor experiment andresponse surface experiment, effect on the protein content of the protease type,enzymatic pH, temperature, substrate concentration, the ratio of enzyme to substrateand enzymolysis time was studied. And the optimal condition for preparation of lowprotein Acaudina molpadioides polysaccharide was explored. Mathematical modelwas successfully established. Combining with the model prediction, the optimalenzymatic hydrolysis condition was determined: enzymatic hydrolysis pH of7.0,temperature of51℃, substrate concentration of4.82%, the ratio of enzyme tosubstrate of4.08%, enzymolysis time of12h. Under the above conditions, the productprotein content was （2.41±0.24）%.Hydrolysate of Acaudina molpadioides contained a large number turbidity. Thenature of turbidity of enzymatic hydrolysate was studied. Turbidity of enzymatichydrolysate was composed of protein, lipid and ash. The surface potential was -46.3mV, and the average particle size was597nm. Turbidity was caused mainly byprotein and lipid, and protein was polymerized by hydrophobic interaction. Acaudinamolpadioides polysaccharide contained large pigment. The nature of pigment wasstudied. Pigment in the polysaccharide was mainly anionic.The ideal method ofenzymatic hydrolysate turbidity elimination was established through the guidance ofturbidity nature. AG-800#diatomaceous earth filtering was adopted, and the turbidityelimination rate was100%. The enzymatic hydrolysate was clear and transparent afterabove treatment. Through the guidance of pigment nature, macroporous resins wereadopted to decolor the Acaudina molpadioides polysaccharide. Mathematical modelof resin D392decolorization was successfully established by single factor experimentand response surface experiment, and the optimum condition was determined: time of5h, pH of10, temperature of60℃. Under the above conditions, the decolorizationrate was （84.2±0.6）%.Based on the above experiment, Protamex was employed. The enzymatichydrolysis conditions was pH of7.0, temperature of51℃, the substrate concentrationof4.82%, the ratio of enzyme to substrate of4.08%, hydrolysis time of12h. Theenzymatic hydrolysate adopted AG-800#diatomaceous earth filtering. Ultrafiltrationthree times, polysaccharide obtained after lyophilized. Resin D392decolorationconditions were time of5h, pH of10, temperature of60℃. Polysaccharide yield was4.2%, the quality was the protein content of2.1%.Aqueous two-phase system was used to separate chondroitin sulfate and fucoidan.Distribution behavior of polysaccharide in the system was studied. Aqueoustwo-phase system was15%PEG10000,12.5%（NH₄）₂SO₄. Protein content ofchondroitin sulfate obtained after separation and purification was0.9%. Proteincontent of fucoidan was1.6%.Summing up the above, key technical points of sea cucumber polysaccharideextraction were captured. Good quality sea cucumber polysaccharide, sea cucumberchondroitin sulfate and sea cucumber fucoidan could be prepared. The results of thispaper provided theoretical basis for development and utilization of Acaudinamolpadioides and Acaudina molpadioides polysaccharide. It was hopeful to promote deep-processing and value-increment of sea cucumber.