| In order to produce calcium supplements which are easily absorbed by the human body and improve the utilization rate of bovine bone,this paper selects bovine bone powder as the basic raw material,prepares bovine bone polypeptide with neutral protease and alkaline protease and optimizes its enzymatic hydrolysis conditions.The calcium source is used to calcium chelate the bovine bone polypeptide,and the preparation method is determined.The microstructure,stability and particle size distribution of the bovine bone polypeptide are confirmed by scanning electron microscopy to determine the particle size distribution and stability index,and the molecular weight distribution range and spectrum of use are determined.Analyze it for structural characterization.Using the degree of hydrolysis as an indicator,the optimal enzymatic hydrolysis combination of neutral and alkaline proteases was optimized by single factor and orthogonal experiments.The experimental results are as follows:The optimal enzymatic hydrolysis conditions for neutral proteases are:enzymatic hydrolysis time 4 h,enzyme addition The amount is 2.5%(m/m),the ratio of material to water is 1:20(m/v),the enzymatic temperature is 50?,and the pH is 7.0.The degree of hydrolysis at this time was 5.93%.The optimal enzymatic hydrolysis conditions for alkaline protease were as follows:enzymatic hydrolysis time 4 h,enzyme addition 2.0%,feed water ratio 1:25,enzymatic hydrolysis temperature 50?,enzymatic hydrolysis pH 8.5.The degree of hydrolysis at this time was 8.14%.The optimal hydrolysis mode of the complex enzyme was studied.It was finally determined that the enzymatic hydrolysis sequence of the two enzymes was first through neutral protease and then through alkaline protease,and the degree of hydrolysis was as high as 19.40%.The color change of the indicator was used as the index to determine the exogenous calcium as calcium chloride.The single factor experiment and orthogonal optimization of the chelation conditions were used to determine the preparation conditions of the peptide calcium chelate by the chelation rate and calcium mass fraction.The chelation time was 40 min,the peptide calcium mass ratio was 2:1,the chelation temperature was 60?,and the pH was 8.0.Under this condition,the calcium mass fraction reached 21.29%and the chelation rate reached 38.97%.Infrared spectroscopy results showed that the secondary structure of protein changed little during enzymatic hydrolysis,while the secondary structure of the chelation process was highly transformed,while carboxyl,amino and peptide bonds involved in the formation of chelate;UV spectrum and fluorescence The spectrum shows that the absorption peak intensity changes during the preparation of the polypeptide,but there is no change in the displacement.The chelation process is the complex reaction of calcium ions with the polypeptide,and the peak shape of the K absorption band of the carbonyl group changes,indicating that the carbonyl group may also participate in chelation.The results of electron microscopy showed that the enzymatic hydrolysis and chelation treatment caused the microstructure to undergo a tight-loose-tight change process,indicating that the binding mode of the material changed,the bovine bone powder was tightly bound,the peptide binding was loose,and the chelate It became tight again;the molecular weight distribution showed that enzymatic hydrolysis hydrolyzed the macromolecule into a polypeptide with a smaller molecular weight,and the chelation effect was better in the molecular weight range of 500-5000 Da.The particle size distribution and stability analysis showed that the enzymatic treatment made the particle size smaller and the stability increased.The chelation treatment made the particle size larger and the stability decreased.The analysis results showed a positive correlation,which proved the stability index.Relationship with particle size.The above results show that a new type of peptide calcium chelate with potential health value is generated. |
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