Controlling the aggregation propensity and thereby digestibility of allergens by Maillardation as illustrated for cod fish parvalbumin

The aggregation propensity of heat-treated codfish parvalbumin is investigated upon Maillardation of the protein under food-relevant conditions. About twelve of the fourteen lysine residues had reacted with glucose under these conditions. It is shown using circular dichroism and fluorescence that extensive coupling of glucose moieties on the protein surface does not affect the secondary and tertiary structural fold nor severely impair calcium-binding under ambient conditions. The glucosylated protein has a 3°C higher denaturation temperature, while the free energy change involved with denaturation is reduced by 5-10%. It is shown by establishing insight in the change in heat capacity involved in the denaturation process that glucosylation of the protein is likely to result in a lower exposed hydrophobicity in the unfolded state. Aggregation kinetics, as monitored using light scattering techniques, shows that this lower exposed hydrophobicity of the denatured state slows down the aggregation process, while the shape and size of formed aggregates are comparable to those formed by non-glucosylated protein. This lower aggregation propensity allows a significantly faster digestion of heat-treated materials by pepsin. This work demonstrates that (pre-)processing of ingredients containing potential allergens, like cod fish parvalbumin, using food-relevant conditions may provide an effective tool to minimize risks of provoked allergic responses during food consumption.