Abstract:

Objective: To investigate the effects of combined rinsing with carboxymethyl chitosan (CBC) and sodium chloride

on gel quality, yield and protein loss of silver carp surimi. Methods: Fresh silver carp meat was rinsed with deionized

water, 0.25%, 0.5%, 0.75%, and 1.0% NaCl solution, 0.5%, 1.0%, 1.5%, and 2.0% CBC solution, 1.0% CBC + 1.0%

NaCl, 1.0% CBC + 0.75% NaCl, 1.5% CBC + 1.0% NaCl, and 1.5% CBC + 0.75% NaCl, respectively (fish meat: rinsing

liquid = 1:5, m/m). Surimi gel strength, whiteness, protein composition and rheological properties were measured. Results:

As NaCl concentration (when used solely) increased, the surimi gel strength and whiteness showed significantly increasing

trends (P < 0.05) and total protein content increased first and then decreased. Both excessively high and excessively low

NaCl concentration had adverse effects on surimi gel yield. Increasing CBC concentration, when used alone, significantly

increased the gel strength, whiteness, water-soluble protein content of surimi (P < 0.05). When minced fish was rinsed with a

combination of CBC and NaCl, the highest gel strength of 232.05 g·cm was obtained using 1.5% CBC + 0.75% NaCl, which

was significantly higher than that (142.22 g·cm) of the blank (P < 0.01). Rinsing with CBC and NaCl in combination was

better than either of them alone. Rinsing with 1.5% CBC + 0.75% NaCl, salt soluble protein content of 10.53%, and watersoluble

protein content of 4.91% were obtained, which were significantly higher than those (9.36% (P < 0.05) and 4.06%

(P < 0.01)) of the blank, respectively. Rinsing with 1.5% CBC + 0.75% NaCl, salt soluble protein content of 10.53%, and

water soluble protein content of 4.91% were obtained, which were significantly higher than those (9.36% (P < 0.05) and

4.06% (P < 0.01)) of the blank, respectively. Moreover good surimi gel strength, whiteness and crude protein content were

obtained. Conclusion: Rinsing with a combination of 1.5% CBC + 0.75% NaCl can improve gel strength of silver carp

surimi and reduce the loss of protein by 10.56%, consequently increasing surimi yield and lowering wastewater production.

Key words: silver carp, surimi, washing, gel strength, carboxymethyl chitosan (CBC)