Effects of high-temperature treatment (≥ 100 °C) on Alaska Pollock (Theragra chalcogramma) surimi gels

Surimi gels from Alaska Pollock were obtained by heating and maintaining their central temperature at 100 +/- 1 degrees C, 105 +/- 1 degrees C, 110 +/- 1 degrees C, 115 +/- 1 degrees C and 120 +/- 1 degrees C for 10 min respectively under a certain pressure (0.12 MPa). With temperature increasing, both the breaking force and gel strength decreased significantly (P < 0.05) while the deformation decreased with a much smaller gradient. The ionic bonds and the hydrophobic interactions declined with a drastic rate while the hydrogen bonds and the disulfide bonds took on an increasing trend on the whole. NMR spin-spin relaxation (T-2) measurements showed that most of the water in the gels is movable water, the peak of T-22 became lower and the relaxation time of T22 became longer with treating temperature increasing. SOS-PAGE showed that high-temperature treatment decreased the content of myosin heavy chain (MHC) entirely and significantly decreased the content of actin. SEM showed that the gel treated with 100 +/- 1 degrees C showed a uniform network structure with strong frames. (C) 2012 Elsevier Ltd. All rights reserved.