GEL CHARACTERISTICS OF BETA-LACTOGLOBULIN, WHEY-PROTEIN CONCENTRATE AND WHEY-PROTEIN ISOLATE

The gelation characteristics of beta-lactoglobulin, whey protein isola te and whey protein concentrate at varying levels of protein (6-11%), sodium chloride (25-400 mM), calcium chloride (10-40 mM) and pH (4.0-8 .0) were studied in a multifactorial design. Small scale deformation o fthe gels was measured by dynamic rheology to give the gel point (degr ees C), complex consistency index (k), complex power law factor (n*) and critical strain (gamma(c)). The gel point decreased and turbidity increased with increasing calcium level. The denaturation temperature measured by differential scanning calorimetry was reduced at higher pH values. Large scale deformation at 20% and 70% compression was measur ed using an Instron Universal Testing machine. The true protein level had the largest effect on the stress required to produce 20% and 70% c ompression and on the consistency (k) of the gels.