Effects of Thermal Processing on IgG/IgE Reactivity, In Vitro Digestibility, and Structural Characteristics of Almond (Prunus dulcis)

Almond was subjected to five kinds of thermal treatments to investigate the effects of heat treatments on IgG/IgE binding capacity, in vitro digestibility, and the structures of almond soluble extracts. The results showed that protein recovery of almond was inhibited by most heat treatments with a similar extent of digestibility, while IgG/IgE reactivity enhanced most in baked almonds, which was related to the structural differences under the heat treatments and the presence or absence of water. Heat-treated almonds had elevated alpha-helix and decreased beta-sheet contents, and the protein surface exposed more hydrophobic amino acids. In almond proteins, especially legumin (AMP), IgG/IgE binding capacity was still maintained after heating, indicating that both raw and heat-treated almonds could cause allergies and AMP could become a reliable marker for almond immunodetection.