Effects of hydrolyzed wheat gluten on the properties of high-temperature (≥100 °C) treated surimi gels

Abstract Previous studies have found that the gel strength of the surimi decreased significantly with treating temperature increasing from 100 °C to 120 °C, which severely reduced the water-holding capacity (WHC), destroyed the network structure and thereby affected the texture of the surimi products. In this study, hydrolyzed wheat gluten (HWG) was added into Alaska Pollock surimi, and gels were obtained by maintaining their central temperature at 100 ± 1 °C, 105 ± 1 °C, 110 ± 1 °C, 115 ± 1 °C and 120 ± 1 °C for 10 min respectively under a certain pressure (0.12 MPa), to explain how HWG affected the thermal stability of the high-temperature treated surimi gels. With temperature increasing, adding HWG significantly increased the texture characteristic of the surimi gels, and the WHC of the plural gels took on a linear upward trend. The Nuclear Magnetic Resonance T 2 relaxation time showed that adding HWG significantly decreased the relaxation time of T 21 . The sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the same results, the content of myosin heavy chain decreased entirely and the content of actin decreased significantly. Scanning electron microscopy results showed that when treating with 120 °C, the network frames of the surimi gels became fragile, while the surimi-HWG gels kept almost the same density and uniformity. Transmission electron microscopy results showed that when treating with 120 °C, the structure of the surimi gels became loose and inhomogeneous, and the protein flocculated and aggregated seriously, while the myofibrillar protein did not aggregate and the HWG dispersed in the network evenly.