Effect of pasta drying temperature on gastrointestinal digestibility and allergenicity of durum wheat proteins

The effects of different drying temperatures (20, 60, 85, 110 and 180 °C) on digestibility and potential allergenicity of durum wheat proteins were studied in model pasta samples, cooked in boiling water (MPSs). Increasing the drying temperature resulted in increased protein denaturation and aggregation. In vitro treatment of MPSs with pepsin and pancreatin showed similar protein degradability up to a drying temperature of 110 °C, resulting in the disappearance of the main prolamin components. In contrast, the MPS treated at 180 °C was much less digestible, due to the presence of Maillard-type protein aggregates. By using sera of patients with food allergy to wheat, the potential allergens of MPSs were detected by IgE-immunoblotting and IgE dot blotting before and after digestion. The results indicated that the digestion process, although sufficient to degrade the wheat proteins in the MPSs dried up to 110 °C, was not able to completely abolish the presence of IgE-reactive peptides, irrespective of the level of the heat-treatment.