Key factors affecting the immunoreactivity of roasted and boiled peanuts: Temperature and water

• Mild roasted temperature or boiling for 10 min can effectively reduce the peanut allergenicity.
• Not only did AGEs lead to increase the immunoreactivity, but also the increased Ara h 2/6 IgE-Binding capacity.
• Hydrogen-bond and hydrophobic interaction which induced by boiling water can change the allergenicity of boiling peanut.

Processing time (5–35 min) and temperature (105 °C–150 °C) during thermal processing may affect the structure and immunoreactivity of peanut allergen protein. In the present study, we aimed to find a correlation between heating mode and characteristics of peanut protein, and optimize the heating condition to reduce the allergenicity. Roasted peanut protein under the condition of extremely high temperature (over 130 °C) resulted in high allergenicity, accompanied with reduced concentration and IgE binding capacity of Ara h 1 and Ara h 3, but increased Ara h 2/6 IgE binding capacity. In addition, the structure of roasted protein under the condition of 130 °C for 20 min was the loosest with higher surface hydrophobicity index, more β-fold and the irregular coil, and less α-helix. In contrast, the allergenicity of boiled peanut proteins was decreased as the concentration and IgE binding capacities of all allergen were reduced. Because of the water medium, all bonding energy in the boiling group was lower than that in the roasting group. Hydrophobic interactions and hydrogen bonds were more prominent on the boiling samples. The finding indicates mild roasted temperature or boiling for 10 min can effectively reduce the peanut allergenicity.