Abstract
Peanut allergy is a persistent and potentially life-threatening immunological disorder triggered primarily by seed storage proteins, including Ara h 1, Ara h 2, and Ara h 3. Conventional thermal food processing methods often fail to eliminate allergenicity and can occasionally enhance IgE reactivity through Maillard-driven neo-epitope formation. In this study, high-pressure processing (HPP) was applied to peanut protein isolates at pressures ranging from 300 to 600 MPa for varying durations (5, 10, and 15 min) at ambient temperature (20 °C) to examine its potential in modulating protein conformation and immunoreactivity. Far-UV circular dichroism (CD) and Fourier-transform infrared (FTIR) spectroscopy revealed marked shifts in secondary structure, characterized by a progressive reduction in α-helical content (from 24.8% to 11.3%) and a concomitant increase in random coils and intermolecular β-sheets at 600 MPa. Intrinsic tryptophan and 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence analyses demonstrated substantial tertiary structure disruption and the exposure of buried hydrophobic cores followed by supramolecular aggregation. Immunological evaluations using enzyme-linked immunosorbent assay (ELISA) and immunoblotting with pooled human allergic sera confirmed a pressure- and time-dependent decrease in IgE-binding capacity, reaching a maximum reduction of 67.4% at 600 MPa for 15 min. These findings demonstrate that HPP-induced structural perturbation and subsequent aggregate formation effectively mask or destroy conformational epitopes, offering a viable non-thermal processing approach for the hypoallergenic modification of peanut-derived ingredients.
