L‐histidine‐assisted ultrasound improved microstructure and gelation properties of reduced‐salt surimi (Hypophthalmichthys molitrix) gel

Summary In this study, the effect of several additives, including CaCl 2 , L‐histidine (L‐His) and sodium pyrophosphate, incorporation with ultrasound treatment on the gel properties of reduced‐salt surimi, was tested. Among these additives and ultrasound treatment times, 0.1% L‐His and 10‐min ultrasound alone were determined to be more effective in increasing the gel strength, water‐holding capacity (WHC) and reducing cooking loss (CL) of reduced‐salt (1% NaCl) surimi gel. L‐His and ultrasound alone or in combination could facilitate the transition of α‐helix to β‐sheet and random coil, thereby increasing hydrophobic interactions and disulfide bonds in the gel. The results of low‐field nuclear magnetic resonance showed that the proportion of immobilised water (PT 22 ) in reduced‐salt surimi gel was significantly increased ( P < 0.05). The storage modulus (G′) of reduced‐salt surimi gel was also increased. Moreover, scanning electron microscopy results showed that the gels treated with L‐His and ultrasound alone or in combination had a more compact network structure. Notably, the synergy of L‐His combined ultrasound treatment was the most effective in enhancing the characteristics of reduced‐salt surimi gel.