Gel properties and thermal gelling mechanism in myofibrillar protein of grass carp (Ctenopharyngodon idellus) under the synergistic effects of radio frequency combined with magnetic field

This study evaluated the effects of radio frequency (RF)-replaced water bath (WB) or/and magnetic field (MF)-assisted WB heating on various quality parameters of grass carp myofibrillar protein (GCMP) gel and to understand the thermal gelling mechanism. Compared with the control, RF-replaced 40°C WB combining MF-assisted 80°C WB heating promoted GCMP structural changes, that was random coil content observably increased from 28.87% to 32.3% at the expense of α-helix reducing from 17.93% to 15.80%, even promoting the self-assembly of exposed residues. These structural changes were conducive to form relatively smooth and loose gel network structures, thus significantly increasing immobilized and bound water and improving water holding capacity. The electrostatic repulsion between exposed residues was conducive to the stability of protein molecules and gel structure. Overall, the RF-replaced 40°C WB combining MF-assisted 80°C WB heating was a desirable thermal alternative to conventional WB heating for improving gel quality.