Gelation properties and molecular dynamics simulation of thermally induced large yellow croaker (Pseudosciaena crocea) roe protein isolate gels

Roes are the main byproducts during the processing of large yellow croaker (Pseudosciaena crocea) and have not been well utilized. Heat-induced gels were prepared by using P. crocea roe protein isolates (pcRPI), and the influence of pH on the gel properties was also investigated. pcRPI could not form a gel at pH 4–6 but showed gelation behaviors at pH 7–9. The pcRPI gels prepared at pH 8 had a lower gel point (84 °C), and their G′ reached 535.4 Pa. Moreover, pcRPI gels formed at pH 8–9 had a more continuous network structure with a shorter T2 relaxation time than those at other pH conditions. Additionally, vitellogenin and vitellogenin B and C in pcRPI easily formed protein complexes during heating. The hydrophobic interactions, which were the main force between protein molecules during heating, as shown by molecular dynamics simulation, also contributed to gel formation. pcRPI has the potential to be used as a novel hydrogel product in food and other fields.