Study On Extraction And Purification Process Of Hyaluronic Acid From Tuna

OBJECTIVE:The research was mainly to study the extraction and purification process of hyaluronic acid from tuna to get optimum technological conditions.METHOD:The experiments obtained optimum conditions from the several stages,that was,pretreatment,extraction,deproteinization and CPC precipitation.In the pretreatment,different multiples of ethanol and acetone were added to evaluate the effects of different kinds and multiples of organic solvents on the dissolution of HA in the precipitation.The experimental conditions were optimized in the extraction process of pure water and enzymatic hydrolysis and then the extraction efficiency of the two methods were compared.Sevag method,isoelectric precipitation and alcohol precipitation were selected to get rid of contaminating protein.Relative reaction condition optimization and comparison of the three methods were done.In the CPC precipitation process,concentration of HA and the amount of CPC added on the impact of the recovery were examined.The last was to detect the final product.RESULTS:In the pre-processing stage,adding 4 times acetone as the optimum conditions precipitation has 31.9%higher dissolution of HA than adding ethanol.Enzyme assisted extraction,whose optimal conditions were 6%dosage,60?,7 of reacting pH,2 hour reacting time,could get 106mg HA per Kg fish eyes as the average extraction rate,while extraction with pure water,whose optimal conditions were adding six,four and three times the amount of water respectively to extract three times totally and extracting for 1 hour each time,could obtain 79.9 mg HA per Kg fish eye.The extraction rate of Enzyme-assisted extraction increased by 32.7%prepared to pure water extraction,indicating that hydrolysis of HA-Protein can significantly raise the extraction rate.When 4 times of 95%ethanol was added in enzymatic hydrolysate,HA recovery ratio reached the maximum value with 99.6%of the protein removal efficiency and 80.2%of the HA recovery rate,far higher than Sevag method with 29.01%and isoelectric precipitation method with22.80%.In the CPC precipitation process,I got the best result of 75.5%of the HA recovery rate and 37.5%of the protein removal rate when HA concentration was about 0.8mg/mL,and 20 times the amount of CPC was added.Hyaluronic acid Purity in the final product was 87.7%,protein content 2.25%,and the HA molecular weight 1.65 � 106 Da.The total recovery of the entire extraction process was 37.6%.Conclusion:This study obtained a simple,relatively high recovery process route and access to high-quality HA products.