| In this paper,the ovalbumin was isolated and purified from egg white protein by anion exchange column technology,and the ovalbumin was glycated by Maillard reaction dry-heat method.The structure of the ovalbumin,the effect of glycation on the physical and chemical properties of ovalbumin was characterized.And an O/W orange peel oil nano-emulsion based on ovalbumin glycation products was developed.The following conclusion was abtained:1.The conditions of separation and purification of ovalbumin by anion exchange column were studied.The results showed that:The conditions of separation and purification of ovalbumin were as follows:the concentration of ovalbumin was 10 mg/mL,the volume of loading sample was 100mL,The ovalbumin was eluted by 0.1,0.2,0.3 mol/L NaCl Tris-HCl(pH8.0)gradient elution.The eluted ovalbumin fineness was 92.31%and 91.20%,respectively.Compared with the salting-out method,the purity of the protein isolated by column chromatography is high and the salt content is low.2.The ovalbumin and D-lactose were used as raw materials to prepare the glycation products by Maillard reaction.The physical and chemical properties and structural characterization of the grafted products were studied.The conclusions are as follows:(1)Changes in free amino acid content,amino acid composition were analyzed,SDS-PAGE confirmed that ovalbumin and lactose in the dry heat treatment conditions of the occurrence of glycation.The molecular weight of the ovalbumin was increased by about 3.5 kDa and the free amino acid content decreased by about 24%after glycation.(2)Analysis by amino acids,ovalbumin and lactose glycosylation,lysine,arginine and tyrosine significantly reduced.From the endogenous fluorescence spectra,the maximum fluorescence intensity of the grafted product at 350 nm was significantly decreased.The carbonyl group was bound to the amino group of the ovalbumin to form a molecular layer of the copolymer,which shielded the hydrophobic group on the surface of the ovalbumin molecule Its fluorescence intensity.(3)SEM images showed that the ovalbumin was modified to form a regular lamellar structure,glycosylated in a chaotic group structure.3.Glycosylated ovalbumin compared with the original ovalbumin:ovalbumin glycosylation of the solubility at pH 5.0 compared to the original ovalbumin compared to significantly increased,which reflects the 12 h after the glycosylated ovalbumin increased The greatest degree,increased by about 40%.Glycosylated ovalbumin bubbles were 30 ml,15 mL more than ovalbumin.DSC analysis showed that the heat denaturation temperature of glycosylated ovalbumin increased from72.46 ~oC to 89.06 ~oC.The product of glycosylated ovalbumin after 12 h incubation was raised from 0.8 m~2/g to 1.2 m~2/g in terms of emulsification.In terms of pH stability,thermal stability and salt ion stability,glycosylated ovalbumin near the point can be effective due to thermal effects and salt ions caused by the phenomenon of aggregation.4.Based on the glycosylation of modified products prepared by the orange peel oil O/W nano-emulsion characteristics are:Synthetic process:water,protein and oil phase of the three mass ratio of 99:1:5,the protein solution pH 4.0,20000 r/min high-speed dispersion 1 min,1000 bar under the pressure of 8 times.The average particle size of the emulsion was 210.2 and the PDI was 0.106.Laser confocal microscopy showed that the glycosylated ovalbumin-based emulsion was an O/W nanoemulsion with a concentration of 8.86 mg per 100 mL of the emulsion.The stability,pH stability,thermal stability and storage stability of the protein were higher than that of the ovalbumin-based emulsion. |
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