The combination system reported in the present study was beneficial for myosin unfolding, facilitating intermolecular interactions between Ca2+ and myosin. Ultrasound treatment promoted myosin aggregation via the induction of Ca2+ and reduced the critical concentration of Ca2+ required to aggregate myosin. In the fish processing industry, this combination system can enhance the gelation properties of surimi-based products. © 2018 Society of Chemical Industry.