Enzymatic Preparation Of Low Antigenic Whey Protein And Product Pilot Design

Whey protein is one of the high-quality protein supplements and is rich in nutrition.It is often used in infant formula milk powder,but after all,unlike human milk,whey protein contains alpha-lactalbumin and beta-lactoglobulin that are easy to cause allergies in infants and children Long-term will also affect the healthy development of infants and young children.Biological enzyme method has become the main technical means for research and development of hypoallergenic dairy products due to the advantages of simple process,mild conditions,strong feasibility and mature technology.Whey protein is an important raw material for the production of infant milk powder.Because of its allergenicity,it is limited in infant milk powder.The appropriate treatment method is used to reduce its allergenicity.For the large-scale application of whey protein the production of hypoallergenic whey protein products is of great significance.After desensitization,whey protein not only can be used normally by allergic people,but also can be more widely used in the development of hypoallergenic dairy products in China.Aiming at the allergy problem,the research of this subject is as follows: using protease to explore enzymatic hydrolysis of whey protein;antigenic detection of whey protein hydrolysate;and pilot scale-up test of whey proteolysis process.The detailed research contents are as follows:1.According to the size of protease activity and degree of hydrolysis,alkaline protease was selected as the enzyme for hydrolysis from five kinds of commonly used proteases in the laboratory.The conditions for the physical hydrolysis of whey protein were studied first,and the physical hydrolysis was determined through single factor experiment The best process;then experiment on the four factors distribution of hydrolysis temperature,hydrolysis time,hydrolysis pH,enzyme to substrate concentration ratio,on the basis of the results obtained in the single factor experiment,and then carry out the enzymolysis process conditions according to the orthogonal experiment optimization.The optimal process for enzymatic hydrolysis of whey protein is: whey protein concentration 20%(w/v),after physical hydrolysis at 80? for10 minutes,according to the hydrolysis temperature of 50?,the enzyme to substrate concentration ratio is 1.3%,and the hydrolysis pH is 8.0,enzymolysis time is 4 h.The hydrolysis degree of the enzymolysis product(HWP)prepared under this process condition is at least 34.73%,at most 35.47%,and is stable at more than 30%.The degree of whey protein hydrolysis is deep hydrolysis.Compared with imported hydrolyzed formula products,it is found that the degree of hydrolysis is higher than brand 3(33.93%),close to brand 1(35.13%)and brand 2(35.07%),slightly lower than brand 4(36.17%).2.The principle of enzymatic hydrolysis to reduce the antigenicity of whey protein was studied.The molecular weight distribution of the hydrolysate was characterized by SDS-PAGE gel electrophoresis,and then the antigenicity was determined by sandwich enzyme-linked immunosorbent assay,and compared with the hydrolyzed whey powder imported from abroad.The result of electrophoresis is that the molecular weight distribution range of hydrolysate is mainly between 3.3 and 14.1kD,and the molecular weight distribution range of foreign countries is mainly below20 kD;the content of hydrolysate beta-lactoglobulin is 131.94 ?g/mL,the antigenicity reduction rate is 89.73%,imported from abroad Brand 4 had the lowest?-lactoglobulin content(159.72 ?g/mL),followed by brand 1(243.06 ?g/mL),brand 2had 548.61 ?g/mL,and brand 3 had the highest content,reaching 715.28 ?g/mL.By comparing with the hydrolyzed products imported from abroad,the hydrolyzed whey protein produced in this study is superior to foreign products of the same type in terms of ?-lactoglobulin content.3.On the basis of small-scale process experiment,the enzymolysis process of whey protease hydrolysis was conducted 10 times scale-up experiment.A series of tests were carried out on the produced hydrolyzed whey protein powder for protein,fat,amino acid content,ash,minerals,and microorganisms,and the experimental results were compared with the properties of the small-scale hydrolysate.The experimental results are: the yield of the pilot product is 87.35%,the moisture content is 4.9%,the protein content is 74.14%,the ash content is 4.8%,the total amino acid content is 840.1±5.2 mg/100 g,and the essential amino acid content is 378.8±2.4mg/100 g,fat content 3.2%,pH 7.1,sodium content 689.3 mg/100 g,calcium content351.8 mg/100 g,potassium content 1174 mg/100 g,magnesium content 65.5 mg/100 g,phosphorus content 129 mg/100 g,the total number of colonies is less than 1000 cfu/g,coliform bacteria,E.coli and Staphylococcus aureus are all less than 10/g,yeast and mold are less than 50 cfu/g,without Salmonella and Listeria.