Impact of Maillard Reaction on Immunoreactivity and Allergenicity of the Hazelnut Allergen Cor a 11

Abstract

Few studies exist on the influence of processing methods on structural changes and allergenic potential of hazelnut proteins. This study focused on the effect of glycation (Maillard reaction) on the immunoreactivity and degranulation capacity of the purified hazelnut 7S globulin, Cor a 11. After heating, the extent of the Maillard reaction, sensitivity to proteolysis, binding of human IgE or rabbit IgG, and degranulation capacity were analyzed. Changes in electrophoretic mobility, amount of free amino groups, and contents of bound sugar and fructosamine indicated that glycation of Cor a 11 occurred at all conditions. Glycation at 37 °C did not influence the specific IgG or IgE binding and was decreased after heating at 60 and 145 °C. Heating, with or without glucose, at 145 °C increased basophil degranulation capacity. The results suggest that glycation of Cor a 11 at 60 and 145 °C may decrease the IgE/IgG binding properties but not the degranulation capacity of basophils. This is possibly related to aggregation of the proteins as a result of the Maillard reaction.

Effects of the Varietal Diversity and the Thermal Treatment on the Protein Profile of Peanuts and Hazelnuts

“…In particular, Cor a 1, Cor a 2, and Cor a 8 were proved to be thermolabile proteins [40][41][42], whereas Cor a 9 and Cor a 11 allergens were considered more thermostable [43][44][45]. In addition, Cor a 9 and Cor a 11, under particular processing condition, could generate Maillard reactions and advanced glycation end products [44,45]. Our findings were in accordance with what was previously reported.…”

“…So far, only a few papers were reported on the evaluation of food processing effects on hazelnut proteins, and most of them focused on the fate of allergenic proteins upon thermal treatment. In particular, Cor a 1, Cor a 2, and Cor a 8 were proved to be thermolabile proteins [40][41][42], whereas Cor a 9 and Cor a 11 allergens were considered more thermostable [43][44][45]. In addition, Cor a 9 and Cor a 11, under particular processing condition, could generate Maillard reactions and advanced glycation end products [44,45].…”

Scientific Opinion on the evaluation of allergenic foods and food ingredients for labelling purposes

“…These modifications have a clinical significance: an anaphylactic reaction to cooked pecan nuts was reported by a patient who showed specific IgE antibodies exclusively against allergenic determinants present in aged or heated pecan, but not in fresh pecans (Malanin et al, 1995). On the contrary, the Maillard reaction decreases the IgE-and IgG-binding properties of the hazelnut allergen Cor a 11 (Iwan et al, 2011).…”

Ovalbumin Modified with Pyrraline, a Maillard Reaction Product, shows Enhanced T-cell Immunogenicity

“…The MR reportedly alters IgE binding and mediator release capacities of some food allergens by glycations (3)(4)(5)(6)(7). Evidence has also accumulated to show that some glycation structures of AGEs could function as immune epitopes for dendritic cells (DCs) (8 -11).…”