VISCOELASTIC CHARACTERISTICS OF WHEY-PROTEIN SYSTEMS AT NEUTRAL PH

The gelation properties of whey proteins alone and in presence of NaCl , KCl, CaCl2 and L-lysine upon heating to 80 degrees C were characteri sed at pH 7 by oscillatory shear measurements. At the sol-gel transiti on, the whey protein system gave G'(omega) and G''(omega) curves with a slope of 0.5-0.6. For higher concentrations the gel behaviour was ty pical for an homogeneous network and whey protein gels present a gel s tructure with a fractal dimension of 2.7. NaCl, KCl, CaCl2 and L-lysin e increased the elasticity of whey protein gels in a similar way. At i onic strength 0.03 the Na-, K- and L-lysine-WP gels obtained were tran sparent, while the Ca-WP gels presented an opaque particulate structur e.