Reducing egg allergies
Eggs often cause allergies, especially in babies and young children due to their immature gastrointestinal epithelial membrane barrier, allowing more proteins through the barrier and into circulation. Allergy sufferers have antibodies against one of the four egg white proteins: ovomucoid, ovalbumin, ovotransferrin and lysozyme. Although most babies outgrow egg allergy by the age of five, some remain allergic for life. An EU-funded project aimed to address this issue by exploiting the property of the transglutaminase enzyme to modify the immunogenic properties of ovalbumin and ovomucoid egg proteins. The ‘Use of microbial transglutaminase to reduce egg protein allergenicity’ (Eggall) project used a multidisciplinary approach to develop enzymatic strategies for treating egg proteins. Transglutaminase is an enzyme that generates the formation of high-strength protein bonds. It is used in various food-processing applications such as processed meat and fish production. Project partners initially investigated the structural stability of the egg proteins to thermal processing and to in vitro digestion with transglutaminase. Simulation experiments were performed with models mimicking gastric followed by duodenal digestion. Using rheological tools, they studied the effect of transglutaminase treatment on the viscoelastic properties of egg proteins. Results demonstrated that transglutaminase mediated protein cross-linking, thereby reducing the rate of proteolysis and potentially inducing physiological responses that could moderate ill-effects of egg white consumption. Furthermore, enzymatic deglycosylation of the ovomucoid protein was performed. Scientists discovered that a combination treatment of sulfhydryl reagent, surfactants and heating could get rid of glycan modifications, which are responsible for the immunological properties of various proteins. The Eggall approach of modifying egg white proteins will lead to the development of healthier foods and help control egg allergy which constitutes a top EU health priority. Apart from reducing healthcare costs, implementation of the Eggall approach will alleviate the suffering of egg allergy.
