Research On Allergenicity Of Glycated Ovalbumin And Development Of Hypoallergenic Products

Eggs are one of the "eight categories" allergens identified by the Food and Agriculture Organization of the United Nations(FAO)and egg allergies have always been the focus and hotspot of food safety and biochemistry in the world.Asian research institutions have found that half of allergy in Asia is caused by eggs.Infants and children are the main victims.At present,there is still no particularly effective treatment for egg allergies.Strictly avoiding the intake of eggs and their products is currently the only and most effective way to prevent egg allergies.However,strictly avoiding the intake of eggs and their products will inevitably cause the miss of important nutrition supplementation in eggs for egg allergy patients.Therefore,the desensitization method of egg protein and its desensitization mechanism have become the key technical and scientific issues in the world.There are studies shown that glycation modification can significantly reduce protein allergenicity and is a safe and effective protein desensitization technology.However,the effect of different glycation conditions on protein allergen is not yet clear,and after glycated protein is ingested by the human body,the structure of intake will be changed by the digestive enzymes in the gastrointestinal tract.It has not been reported how the allergenicity of intake protein changes.Therefore,this study uses ovalbumin as a raw material to study the effect of different hexoses on the allergenicity(IgG/IgE binding capacity)of ovalbumin,compare the digestion characteristics of native and glycated ovalbumin during in vitro digestion and IgG/IgE binding capacity to reveal the effect of glycation on the digestibility of ovalbumin and the allergenicity of digested products,research and development of hypoallergenic peptide products,and accomplish a factory design.The main research conclusions are as follows:1.The effects of three hexoses such as glucose,galactose,and fructose on ovalbumin allergenicity and structure are compared.The results show that the rate of glycation of galactose and ovalbumin is similar to glucose and much higher than fructose;the degree of allergen reduction of ovalbumin modified by galactose is also similar to that of glucose and much higher than fructose;2.Glycation reaction unfolds the molecular structure of ovalbumin,increases the free content and decreases the surface hydrophobicity.Moreover,glycation can increase the ultraviolet absorption but decrease the intrinsic fluorescence intensity and synchronous fluorescence intensity,as well as decrease the IgG/IgE binding ability;3.Analysis results of glycation modification sites identified by HPLC-MS/MS showed that glycation modification mainly occurs in the β-sheet region of ovalbumin molecule,the main glycation site is lysine,and galactose modification had the most ovalbumin glycation sites;4.Comparing the digestion characteristics and allergenicity of glucose-modified ovalbumin and native ovalbumin after in vitro digestion,the results show that during the digestion process,glycated ovalbumin or native ovalbumin mainly produces peptides below 1 kDa or 1～3 kDa,and both of which have reduced IgG/IgE binding capacity,but the reduction of glycated ovalbumin is lower than that of native OVA.Glycation can be effectively reduced digestibility of ovalbumin;5.The factory design of low-allergenicity ovalbumin peptides with an annual output of 1250 tons has completed.The factory runs 250 days a year,and produces 5 t products per day within 10 h.the workshop covers an area of 1919 m2.The product sales are 125 million yuan per year,the consumption cost is 96.87 million yuan per year,the annual net profit is 28.13 million yuan,the annual profit rate is 22.5%,and the fixed investment cost recovery period is about 1.5 years.