Strategy for Foaming Improvement ofWhey Protein Concentrates by Addition ofHydroxypropylmethylcellulose and Heating:Relation with Interfacial Properties

The objective of this work was to determine the effect of heat application on whey protein concentrate (WPC) in combination with hydroxypropylmethylcellulose (HPMC) addition to improve the foaming properties of the system and to relation these with the interfacial ones. Under these conditions 1 × 10-2 and 1% w/w of whey protein solutions were mixed with 1 × 10-2 and 1% w/w of polysaccharide. Solutions were heat treated for 30 min using a thermostatic bath at 90°C. The foams were produced using a foaming commercial instrument. Foam formation and their stability were measured by conductimetric and optical methods. Time-dependent surface pressure (π); kinetics of absorption and dilatational properties of adsorbed WPC/E4M mixed films at the air–water interface was performed by an automatic drop tensiometer. WPC1%/E4M 1 × 10-2% showed the best combination of biopolymers concentrations to increase foaming properties upon heat treatment. WPC aggregation concomitantly with a great polysaccharide capacity of molecular reorganization at the air-liquid interface could be the reason for these finding. The results showed here have their rheological implicances. WPC did not foam at any of the studied concentrations.