Alteration of collagen thermal denaturation, structural and the abrogation of allergenicity in eel skin induced by ohmic heating

This study aimed to evaluate the effect of ohmic heating (OH) on the thermal denaturation, structure, and allergenicity of collagen in fresh eel skin. The allergenicity of collagen decreased by approximately 70% at 50 °C as measured by simulated gastric fluid (SGF), simulated intestinal fluid (SIF) and ELISA in vitro. SDS-PAGE analysis showed that the molecular weight of collagen did not decrease, but the band strength decreased with an increase in the processing temperature. FTIR and SEM analyses showed that the secondary structure and microstructure of collagen also changed. The water retention, dielectric properties and amino acid content of collagen also decreased with increasing temperature. Compared to water bath heating (WH), OH required significantly less time and energy and reduced the allergenicity of fish skin collagen through protein unfolding and secondary structure changes, thus potentially reducing the allergenicity of eel.