Selective reduction of major egg white allergens (Gal d 1–4) by cold atmospheric plasma: Structural insights and processing optimization

Abstract

This study investigated cold atmospheric plasma (CAP) as a sustainable non-thermal strategy to reduce the immunoreactivity of major egg white allergens (Gal d 1–4). A face-centered central composite design (CCD) was employed to optimize CAP parameters (sample thickness and exposure time), resulting in highly predictive reduced cubic models ( R 2 > 0.97). Optimal conditions (1 mm, 3 min) yielded immunoreactivity reductions of 70%, 68%, 52%, and 6% for Gal d 4, 2, 1, and 3, respectively. The allergenicity mitigation was strongly associated with the accumulation of plasma-generated reactive oxygen and nitrogen species (RONS), which triggered significant molecular transitions. FTIR analysis confirmed key structural changes, including the oxidation of aromatic side chains and a prominent increase in β-sheet content (+12.6% at 1697 cm−1), indicating oxidative-induced structural reshuffling and epitope masking. While CAP served as a mild microbial hurdle, the optimized process effectively maintained the liquid state of the product. These findings demonstrate that CAP is a precision processing tool, validated by robust statistical and molecular evidence, for tailoring the allergenicity of liquid egg products.