Study Of Graded Purification Of Yolk Immunoglobulin Based On Membrane Separation Technology And Production Line Design

Yolk Immunoglobulin（IgY）is a biologically active protein derived from egg yolk with high stability,strong immune response,and low production cost,etc.IgY is a promising alternative to antibiotics in a wide range of applications,including food,diagnostic reagents,and daily hygiene and disinfection products.In order to better meet the actual needs of IgY applications in different scenarios,it is necessary to consider the purity,yield and production cost of IgY,and to produce IgY products with different purity levels for the production cost and different application requirements.Currently most studies on the isolation and purification of IgY are at the laboratory stage.In order to solve the problems of cumbersome operation,high energy consumption,long time consuming and low purity of IgY in the current industrial production of IgY.In this study,a set of preparation techniques for large-scale graded purification of IgY was established by combining continuous flow centrifugation technology,dynamic staggered-flow filtration technology and salting purification.Four kinds of IgY products with different purity levels can be obtained according to the process flow,and the industrial production line design was carried out to provide some theoretical basis for the industrial production of IgY.The main findings of the study are as follows.（1）Study of pilot process conditions for IgY extraction by water dilution.In this chapter,the effects of temperature,water dilution,p H and continuous flow centrifugation on the separation of egg yolk plasma and lipoprotein removal were investigated by combining the water dilution method with the continuous flow centrifugation technique.The optimal water dilution conditions were water dilution of 1:9,p H 5.0,and treatment temperature of 0℃.The concentration of soluble protein in the supernatant was 193.23mg/m L egg yolk,and the lipid removal rate reached more than 99%,which was the best for the removal of egg yolk particles and suitable for the preliminary separation of IgY.The optimum continuous flow condition was centrifugation at 12,000×g for one time,and the soluble protein concentration in the supernatant was 188.60 mg/m L egg yolk,with a protein loss rate of 2.40%and a lipid removal rate of 97.50%,and a high removal rate of miscellaneous proteins.The purity of the final IgY-Ⅰproduct was 30.69%,and the yield was25.06 mg/m L egg yolk.The method established in this chapter can provide a certain theoretical basis for the mass processing of diluted egg yolk during IgY extraction,which was of great significance for the subsequent large-scale production of IgY.（2）Concentration and purification of IgY dilutions by dynamic cross-flow membrane separation technology.In this chapter,dynamic cross-flow filtration technology was used to concentrate IgY diluent,and the effects of different membrane pore sizes,membrane rotational speed and transmembrane pressure on membrane separation efficiency and IgY separation were investigated.The optimum membrane separation conditions were 30 nm pore size,1200 r/min membrane speed and 0.2 MPa transmembrane pressure,which resulted in the highest average flux（46.36 L/m²/h）,the concentration rate was 85.37%,the purity of IgY-Ⅱproduct was 35.84%,and the yield was 21.76 mg/m L egg yolk,which was higher than the current commercially available IgY products.This technique can concentrate IgY dilutions on a large scale,and has the advantages of mild conditions,convenient operation and high efficiency.It can effectively solve the problems of excessive volume and high operational load of the water dilution method,and facilitate the subsequent purification steps.（3）Study on the preparation of high purity IgY by salting purification.In this chapter,a combination of（NH₄）₂SO₄ and Na Cl was used for the purification of IgY by salinization,and the effects of different salt concentrations on the purity and yield of IgY and the effects of different drying methods on the quality of IgY products were investigated the purity of the obtained IgY-Ⅲand IgY-Ⅳproducts were 67.17%and 96.90%,respectively.The optimum drying method was vacuum low temperature spray drying,and the resulting IgY products have better fluidity with moisture content of 2.44%,solubility of 93.30%and bulk density of 0.48 g/cm³,which was higher than other IgY products.This method can conveniently and effectively improve the purity of IgY,while reducing the usage of reagents,which was a very cost-effective industrial purification method.（4）Design of multi-stage IgY production line for processing 3500 tons of raw eggs per year.Fully automated equipment was used,and the whole production line complies with HACCP standards to ensure the safety,stability and consistency of the product.The design was comprehensive through the product scheme,process flow,production process accounting,equipment selection and production plant design,auxiliary facilities and comprehensive management.After economic evaluation,the fixed investment amount of the project was 9.83 million yuan,the total annual production cost was 15.1075 million yuan,the annual net profit was 52.46 million yuan,the sales profit rate was 42.39%,and the payback period was 2.67 years.The project can theoretically drive the employment of more than 60 local people and promote the development of egg product deep processing industry,with good social and economic benefits.