Protein concentration, sodium chloride and polyphosphates affect apparent viscosity of sodium caseinate gels

Response surface methodology was used to approach the influence of protein concentration, NaCI and polyphosphates addition on the viscosity of the sodium caseinate gels. The model obtained through experimental design for this influence had R 2 = 0.80887. Viscosity of sodium caseinate gels showed a quadratic dependence on protein concentration and it was a positive interaction between protein concentration and NaCl addition but a negative interaction between NaCl and polyphosphates addition. At protein concentrations of 15 - 18 %, maximum viscosity is obtained at addition levels of 0,5 % polyphosphates and 1.8-2.6 % NaCl.