Study On Continuous Extraction Technology Of Main Natural Active Substances From Egg White

The total output of eggs in China ranks first in the world,but the degree of intensive processing and utilization of egg components is low.The natural active substances in egg white such as ovomucin,lysozyme,ovotransferrin and ovalbumin have not been fully exploited.The study of efficient extraction technology can provide functional materials for the development of functional food and improve the added value of eggs.In this study,egg white is used as raw material,the continuous extraction process of main proteins from egg white was studied based on the final yield and purity of protein and the functional properties of each protein commonly used in food processing industry.The main results are as follows:(1)Ovomucin was extracted by salting out and isoelectric point precipitation method.The extraction process was optimized by response surface method.The optimum process parameters were obtained as follows: concentration of Na Cl solution 1.5mol/L,ratio of egg white to Na Cl solution 1:4,p H 5.5 and 40 min at 3500 g rotational speed.Under these conditions,the yield of ovomucin was 54.32% and the purity was 94.26%.The MIC of ovomucin against Staphylococcus aureus was 50 μg / m L.(2)Lysozyme was extracted by cation chromatography exchange method,and the lysozyme extraction process was optimized by response surface method.The optimum process parameters were obtained as follows: mobile phase p H 8,sample feeding speed0.8m L/min,elution solution concentration 1mol/L,elution rate 0.6m L/min.Under these conditions,the lysozyme yield was 87.1%,the purity was 90.17%,and the enzyme activity reached 104689U/mg.(3)Ovotransferrin was extracted by anion chromatographic exchange method.The extraction process of ovotransferrin was optimized by response surface method.The optimum parameters were obtained as follows: mobile phase p H 8.5,sample loading rate0.8m L/min,eluent concentration 1.3mol/L,elution rate 0.6m L/min.Under these conditions,the yield of ovotransferrin was 81.57%,and the purity was 95.5%.Transferrin activity is that a sample of ovotransferrin molecules can bind to two iron ions.(4)Ovalbumin was extracted by anion chromatographic exchange method.The extraction process of ovalbumin was optimized by response surface method.The optimum parameters were obtained as follows: mobile phase p H 8,sample feeding speed0.6m L/min,eluent concentration 1.5mol/L,elution rate 0.6m L/min.Under these conditions,the yield,purity and foaming ability of ovalbumin were 85.61%,95.43% and149.39%,respectively.The foam retention volume is 72.47% after homogenization stopped 30 min,and it shows good emulsification and emulsification stability.