Physico-chemical and functional properties of commercial caseinates

Abstract

The composition, physico-chemical and functional properties of various commercial caseinates were analysed. The protein content was higher, while density and particle size were lower in Ca than in Na, K, Ca/Na or Ca/K caseinates. Ca caseinates had a significantly lower solubility index, water absorption capacity and apparent viscosity than other caseinates. The solubility index at 20 g/L (at both pH 7.0 and spontaneous pH) varied from 0.81 to 0.97 g/g for Ca caseinates, and from 0.89 to 0.99 g/g for Na or K caseinates. The water absorption capacity (Baumann apparatus, 30 min at 20°C) varied from 1.3 to 1.9 mL water/g powder (Ca caseinates) and from 2.1 to 3.2 mL/g (Na or K caseinates). The apparent viscosity at 150s-1 varied from 40 to 1150 mPa.s (Ca caseinates) and from 500 to 3200 mPa.s (Na or K caseinates). For Ca caseinates, variability was observed between different batches from the same manufacturer. However, the calcium content was positively correlated to pH and negatively correlated to solubility index, rate of water absorption and apparent viscosity. These three latter properties were positively correlated to each other, but they were modified for mixed caseinates containing Ca plus Na or K. © 1993 Academic Press.