Development of a Low-Sodium Soaking Solution for Shrimp Processing Using Potassium Phosphates (KTPP and TKPP) and L-Lysine: Impacts on Quality and Water-Holding Capacity.

A low-sodium soaking solution for Pacific white shrimp was developed by partially substituting sodium tripolyphosphate (STPP) with potassium tripolyphosphate (KTPP) or tetrapotassium pyrophosphate (TKPP) (0.5-2.5%, w/v) in combination with L-lysine (2%, w/v). The effects on physicochemical properties, microstructure, and consumer acceptance were evaluated in comparison with a non-soaked control and a positive control (3% STPP, w/v). The results indicated that partial substitution of STPP with KTPP or TKPP could be effectively achieved while maintaining processing yield, color, and water-holding capacity (WHC) comparable to the positive control. Scanning electron microscopy revealed a more relaxed and expanded muscle structure, indicating enhanced water retention and reduced shear force. However, no significant differences in shear force were observed between the substitution treatments and the positive control. Substitution with KTPP or TKPP significantly reduced phosphate content and the Na/K ratio. Sodium levels decreased by 23.5-47.0% with KTPP and 28.8-59.5% with TKPP, while potassium content increased in the treated shrimp. This substitution did not adversely affect consumer acceptance, with improved taste characteristics, particularly enhanced saltiness and umami, detected by electronic-tongue analysis. Overall, replacing STPP with KTPP or TKPP shows potential as a strategy for developing reduced-sodium shrimp products while maintaining product quality.