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

摘要

Surimi gels from Alaska Pollock were obtained by heating and maintaining their central temperature at 100 ±1 ℃, 105 ±1 ℃, 110 + 1 ℃, 115 ±1 ℃and 120 ± 1 ℃ for lOmin 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 T_(22) became longer with treating temperature increasing. SDS-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 ℃ showed a uniform network structure with strong frames.