Comparison of Gelation Mechanism of Surimi between Heat and Pressure Treatment by Using Rheological and NMR Relaxation Measurements

Abstract

ABSTRACT: The stress‐relaxation and nuclear magnetic resonance (NMR) proton spin‐spin relaxation time ( 1 H T 2 ) measurements were performed to elucidate the gelation mechanism of heated and pressurized surimi gels. Numerical inverse Laplace transformation of the stress‐relaxation data showedlarge distributions of stress‐relaxation times and the Kohlrauch‐Williams‐Watts (KWW) equation described well the stress‐relaxation process for each gel. NMR measurement gave information about the content of the exposed protein surface. From these results it is considered that the heat treatment induces the denaturation and re‐aggregation of protein, which contribute to the formation of strong network structure. On the other hand, the pressure treatment contributes to the formation of weak cross‐links made by the aggregation of protein in native form.