Impact of Thermal Processing on Cashew Ana o 3: Multifaceted Insights into Structural Changes, IgE Binding Capacity, and In Vivo Allergenicity

Reducing cashew nut allergenicity is critical for ensuring sustainable utilization of nut resources and safeguarding the health of individuals with cashew allergies. Here, we investigated the effects of different thermal processing, including water bath (WB), oil bath (OB), and microwave (MW) processing, on the structure and allergenicity of the major allergen Ana o 3 in cashew nuts. Results showed that WB and MW caused minor structural changes with negligible effects on IgE binding. OB treatment significantly denatured Ana o 3, primarily through the loss of its small subunit, which resulted in a marked reduction of its IgE-binding capacity. In vivo, only OB processing prevented anaphylactic hypothermia, accompanied by suppressed Th2-type inflammation, mast cell infiltration, and the activation of allergy-associated genes. These findings highlight that the effectiveness of thermal processing as a strategy for developing hypoallergenic nut products is highly method-dependent, with high-temperature OB treatment showing the most promising results, offering insights into food allergy management.