The usefulness of conductimetric measurements for the proper interpretation of foaming properties on biopolymer interactions

The bubbling method is unique in forming foam with precise control over the liquid and gas used, ensuring the exact density of the foam—unlike whipping and other techniques. This method also allows for analyzing parameters beyond the commonly studied foam volume and drainage or collapse time. In this study, we focused on the exact foaming time, gas volume incorporated, and liquid volume used for foam formation. Foam properties were measured using conductimetric and optical methods. Acidic conditions, typical in food and beverage preparation, can influence the performance of foams, especially when anionic polysaccharides are added for viscosity. These interactions may destabilize the foam. The objective was to examine the effect of polysaccharides on the formation and stability of foams made with whey protein isolate and two hydroxypropylmethylcelluloses (E4M and E50lv) under acidic conditions using the bubbling method. Whey protein isolate + E4M systems showed good liquid incorporation, while whey protein isolate + E50lv systems were highly efficient in gas incorporation, resulting in very stable foams with less liquid drainage.