The Effects Of Processing On The Immunoactivity Of Ovalbumin

Egg allergy is one of many factors that harm the health of many children and a few adults.Ovalbumin is one of the most important allergens in egg.The paper established the Immunological method to detect ovalbumin and studied the impact of heat and pressure on immunoreactivity and structure of ovalbumin.The indirect competitive ELISA method was established based on the production of specific polyclonal antibody for ovalbumin,the IC50 value of the method is 1.22 ± 0.075μg/mL.The processing conditions were moist-heating at 60 ℃,100 ℃,dry-heating at 100 ℃,150 ℃,200 ℃,autoclave sterilization treatment,high pressure processing(400MPa、500MPa、600MPa).Protein recovery was used to measure the solubility of the samples,I50ofthe indirect ELISA was used to measure the immunoreactivity,the primary structure of the protein was determined by SDS-PAGE,the secondary structure of the protein was determined by circular dichroism.With moist-heating treatment at 100℃,dry-heating at 150℃ and autoclave sterilization treatment to the sample solution,the solubility of ovalbumin declined,which was due to the exposure of hydrophobic group.While with high pressure 400MPa,500MPa,600MPa treatment to both solid sample and sample solutions had no obvious effect on solibility of ovalbumin.Dry-heating at 200℃ processing and autoclave sterilization treatment to the solid sample caused the solubility of the ovalbumin samples decreased to almost zero,indicating ovalbumin undergone great changes.The reason of the former was the exposure of hydrophobic group under high pressure.The reason of the latter was the increase in surface hydrophobicity at higher moisture.Autoclave sterilization treatment to the sample solution and moist-heating treatment at 100℃ caused greatly decrease in immunoactivity,and CD results showed that β-sheet structure increased in structure with the sacrifice of helix,it meaned aggregation occured,so the antigen epitope might be hided.While moist-heating at 60℃、dry-heating at 150℃、200℃ treatment、high pressure treatment had no significant effects on the immunoactivity of ovalbumin.SDS-PAGE results of all the samples showed that there were no change in the primary structure of the protein except samples of moist-heating at 200℃ and autoclave sterilization treatment to the solid solution samples.