Reducing allergenicity of Trachinotus ovatus parvalbumin: Insights into digestibility and IgE-binding ability after dense phase CO₂ treatment.

Parvalbumin (PV), a thermostable and digestion-resistant fish allergen, has been shown to retain its allergenic potential following traditional treatments, thus posing a persistent allergic risk. The study investigated the digestive kinetics and IgE immunoreactivity of Trachinotus ovatus PV, a major fish allergen, under different treatments (untreated; dense phase carbon dioxide (DPCD) treatment-15 MPa, 30 min, 50 °C; heat treatment), to evaluate its allergenic potential alterations. The analysis was conducted using a combination of techniques to assess the proteolytic stability and IgE-binding capacity of PV, including tris-tricine-SDS-PAGE, Western blot (WB), indirect enzyme-linked immunosorbent assay (ELISA), and free amino group quantification. The results demonstrated that pretreatment with DPCD significantly enhanced pepsin-mediated PV degradation, achieving hydrolysis and digestibility rates of 86.6 % and 86.4 %, respectively. The 90.9 % inhibition rate of IgE further suggested that the digested products were of reduced allergenicity. Furthermore, DPCD treatment accelerates the processes of α-chymotrypsin digestion. The results of the present study indicate that DPCD intervention improves gastrointestinal degradation of PV protein and attenuates the IgE reactivity of its breakdown products, suggesting its applicability as a novel non-thermal processing approach to mitigate allergenic risks in fish-allergic populations.