Preparation And Characterization Of Nattokinase Microcapsules

Nattokinase(NK,EC 3.4.21.62)is a serine protease extracted from the traditional fermentation product-Natto.It is a protein with extremely high fibrinolytic activity and has a strong thrombolytic activity.effect.The natto is fermented from foreign products such as vegetable soybeans left over by the company after export,and nattokinase is extracted.However,nattokinase is easy to inactivate under certain conditions.Therefore,considering the application of nattokinase,the main purpose of this research is to prepare a nattokinase microcapsule,which can effectively improve the stability of the enzyme activity of nattokinase and lay the foundation for its future application as a thrombolytic preparation.The optimal preparation process of nattokinase microcapsules determined by single factor and orthogonal experiment is: the mass fractions of sodium alginate,sodium carboxymethyl cellulose and nattokinase was 0.5%,0.1% and 0.4%,respectively.The entrapment rate of nattokinase microcapsules prepared under this condition reached97.03±1.63%,and the particle size was 0.53±3.89 mm.Scanning electron microscope observation results show that the prepared microcapsules have a smooth surface.Part of the properties of nattokinase naked enzyme and nattokinase microcapsules were tested.The results showed that the optimum p H value of nattokinase naked enzyme and nattokinase microcapsules were both 8.0,and the p H range was 6.0?8.0Stable.At p H 5.0,the enzyme activity of nattokinase microcapsules is increased by 9.34%compared with crude nattokinase solution;the optimum temperature for nattokinase naked enzyme and nattokinase microcapsules is 25?,at 60°C,the relative remaining enzyme activity of nattokinase microcapsules after being placed for 60 minutes increased by 9.45% compared with nattokinase naked enzyme;the storage stability test results of the nattokinase microcapsules show that the nattokinase microcapsules are placed under freezing and cold storage conditions.After 30 days,the embedding rate still reached more than 80%,which was35.73% higher than that of nattokinase naked enzyme.Through simulated gastrointestinal tract experiments,it was found that the initial enzyme activity of nattokinase microcapsules was 5872.53±473.45IU/m L,the release rate in simulated gastric juice was 4.88±3.89%,and the remaining enzyme activity was 5586.18±228.42 IU/m L,which was released in simulated bile.The rate was 18.06±1.47%,the remaining enzyme activity was 4812.12±86.10 IU/m L,the release rate in simulated intestinal fluid was 73.43±1.19%,and the remaining enzyme activity was 4312.08±69.86 IU/m L.The results of the thrombolytic experiment of nattokinase in vitro showed that the thrombolytic rate of nattokinase microcapsules in vitro was 4.38% lower than that of free nattokinase,the rate of thrombolysis has not decreased significantly,indicating that nattokinase microcapsules did not change the thrombolytic properties of nattokinase.