Effects of Camellia oleifera Seed-cake Crude Protein on the Gel Properties of Silver Carp Surimi

To clarify the effect of Camellia oleifera seed-cake crude protein (COCP) on the gel properties of silver carp surimi, this study incorporated COCP at different concentrations and measured the gel^’s water holding capacity, cooking loss, whiteness, texture profile, and chemical bond content. Fourier-transform infrared spectroscopy and scanning electron microscopy were used to further examine the effects of COCP on the secondary structure and microstructure of the gel proteins. The addition of 1.5% COCP resulted in an optimal water holding capacity (81.12%±0.52%) and texture properties (hardness, 3564.49±24.09 g; elasticity, 0.92±0.01 mm; cohesiveness, 0.72±0.02; and chewiness, 2378.48±115.67 mJ). Also, the cooking loss rate (14.33%±0.88%) was the lowest. Fourier-transform infrared spectroscopy revealed that the stability of the secondary structure of gel protein was enhanced by the addition of COCP. The hydrophobic interaction and total sulfhydryl content of the surimi gel were significantly increased with the addition of 1.5% COCP compared to pure surimi. This resulted in a more ordered microstructure and improved gel properties, although there was a slight decrease in whiteness. In conclusion, the addition of 1.5% COCP significantly improved the properties of the surimi gel.