Study Of Reclamation Of Whey Protein Based On Technology Of Ultrafiltration Membrane Separation

This research made use of the whey which was from the waste liquid of casein in production as research object. Studied the process of the whey protein recovery from waste liquid of casein whey by using ultrafiltration membrane separation technology and spray drying.Through comparing properties of different ultrafiltration membrane, selected the best material of ultrafiltration membrane. separation and drying process and operating parameters were studied, and the quality of whey protein powder was determined, to confirm the optimal process and operating parameters of whey protein powder production. The main results were as follows:(1) the physical and chemical indicators of waste fluids of casein were measured and analyzed comprehensive,the results was: protein 0.62 g/100g,lactose 5.85 g/100g,chloride 0.73 g/100g, ash 0.86 g/100g, pH values 4.17,density 1.05,viscosity 1.37, turbidity 5NTU, milky white,chemical oxygen demand( COD_cr) was 63148.8mg / L, biochemical oxygen demand( BOD5) was 13229.5mg / L.(2) the trial use of the membrane components was PW2540F1030 roll membrane, the effective membrane area of the membrane material was 2.51m2,water operating pressure 0.5¹MPa,operating range of pH values 2¹1,cleaning range of pH value 2¹1.5.(3) ultrafiltration membrane separation process of whey were confirmed:the inlet pressure was 0.5MPa,the temperature 35℃,use of intermittent operation.(4) through the ultrafiltration membrane treatment,the protein content in the ultrafiltration concentrate liquid was 4.87 g/100g,34.79 times higher than permeate liquid,compared with the whey, rejection rate of lactose was nearly 93.68%, removal rate of ash was 70.93%, desalination rate was 73.97%. Comparison of UF concentrate liquid and whey protein can see that the effect of protein retention was obvious.(5) turbidity of emissions obtained by ultrafiltration and nanofiltration treatment was significantly lower,colorless and transparent.After treatment, COD_cr (mg / L),BOD5 (mg/L) removal rate was Respectively 96.62%, 98.67%, indicating that the effect of membrane treatment processes to improve water quality in the sewage plant was significant,the use of membrane separation technology to recover whey protein from the waste liquid of casein whey has a good environmental benefits.(6) The optimal process parameters for spray-drying were:homogenization pressure 45 Mpa, homogenization temperature 45℃, inlet air temperature 170℃, outlet air temperature 70℃,water content of whey protein powder was 3.89 g/100g.the best combination of validation test results showed that water content of whey protein powder was 4.17 g/100g.Partial correlation analysis results showed that there were negative correlation between outlet air temperature and water content, but significant. Homogene pressure and temperature,as well as the inlet air temperature were negatively correlated to and no significant impacted on the water content.(7)Based on the above results, the total process of whey protein recovery was whey isolated, Ultrafiltration concentrate liquid were obtained by ultrafiltration membrane separation process,whey protein powder obtained after spray drying of concentrated solution,which was packaged for the finished product .(8) Follow the best process parameter above, evaluation of whey protein powder: protein 72.4 g/100g,lactose 6.70 g/100g,chloride 3.50 g/100g,ash 3.85 g/100g,water content 4.17g/100g,in line with the national standard of physical and chemical specifications requirements.Products was dry and uniform white powder,fine particles,no agglomeration,no visible impurities in normal vision and sensory indicators in line with relevant national standards. Infra-red spectrum results showed that the form of whey protein powder,the peaks of the functional groups significantly.lactose, dust and other impurities in whey protein powder removal rate was high,some adverse effects on the color and flavor significantly reduced,high purity products.(9) by solid balance,we can get 5.13 Kg whey protein powder per ton whey after spray drying,whey protein powder recovery (Recovery Rate) was 82.74%. Therefore,after ultrafiltration membrane separation technology, we can get high protein content of whey protein powder,and had a better economic efficiency and environmental effectiveness of emissions reduction.In summary, the methods of membrane separation and recovery whey protein in whey was simple and has an good separation and high recovery. After ultrafiltration and nanofiltration treatment on whey obtained nanofiltration permeate,its COD_cr (mg / L) and BOD5 removal rate was high. The effect of membrane treatment processes to improve water quality in the sewage plant was significant.Therefore,in this study,membrane separation technology to recover whey proteins from whey for production applications provide a scientific basis, and also for the full development and utilization of whey resources provide an effective method.