Effects of Non-muscle Protein on Gel Properties of Unwashed Clarias gariepinus surimi

In order to further enhance the gel properties of Clarias gariepinus(CG)surimi unwashed. In this experiment,on the basis of adding 0.4% transglutaminase and 20 mmol/kg CaCl₂ to CG surimi(CK group),different concentrations of soy protein isolation(SPI),egg white protein(EWP)and whey protein concentrate(WPC)were added successively. The amount of SPI added was 2%(SPIL),5%(SPIM),and 7%(SPIH)of CG surimi meat. The amount of EWP added was recorded as EWPL(0.1%),EWPM(0.3%),and EWPH(0.5%). WPC is recorded as WPCL(0.2%),WPCM(0.4%),and WPCH(0.6%). A total of 10 groups of CG surimi gels were prepared. The effects of these non-muscle proteins on the gel properties,color,water holding capacity,dynamic rheological properties and microstructure of CG surimi were studied. The results showed that the addition of non-muscle protein increased the gel properties and TGase activity of CG surimi. Compared with each group,CG surimi gels of SPIL,EWPH and WPCL showed higher gel strength,which was 3322.46,3555.90 and 4149.31 g·mm,and the network structure was closer and more uniform than that of other groups. The concentration of EWP and WPC increased the whiteness of CG surimi gel by adding three concentrations. SPI could make the T₂₂ of CG surimi gel migrate to the direction of short relaxation time,and gel water holding capacity(86.64%)of SPIH group were the highest. The dynamic rheological results also showed that the three non-muscle proteins had a significant effect on the elastic modulus G' and loss modulus G″ of CG surimi,and the SPIH,EWPM and WPCL groups were the maximum values in each group. In summary,the gel characteristics of CG surimi were significantly increased by adding 2% SPI,0.5% EWP and 0.2% WPC in surimi gel respectively in CG surimi gel.