The aim of this study was to understand the effect of the mixing operation in the manufacturing process of surimi seafood. The approach was to work on an actual product and equipment representative of that used in the industry. Surimi seafood paste was characterized in different mixing durations by measurements of particle size, protein solubility and water absorption, temperature and viscoelastic properties, in order to follow the structural modifications and the interactions generated by the mixing process. Two major periods are highlighted during the process: in the first step, the frozen surimi melts; therefore, the shredding of fibers causes a huge reduction in particle size and protein solubilization. Then, temperature increases due to viscous heating. Temperature augmentation leads to denaturation and aggregation of proteins. This then render to the formation of a gel network that will be broken by the ongoing mixing operation. This clearly shows that, during this second step, overmixing affects the functionality of proteins. This functionality is countered by the gelling due to the increase in temperature and subsequent degradation in the mixing process during the gel formation. (C) 2011 Elsevier Ltd. All rights reserved.