Microparticulated whey protein addition modulates rheological and microstructural properties of high-protein acid milk gels

Abstract

The demand for low-fat, high-protein dairy products, such as yoghurts and fresh cheeses is growing considerably. However, reduction of fat, with a concomitant increase in protein, contributes to textural and functional challenges in the finished products. The aim of this study was to investigate how the rheological, microstructural, textural and water holding properties of acid-induced milk protein gels are influenced by the addition of a commercial protein-based fat replacer (Simplesse® 100), i.e., microparticulated whey protein (MWP). MWP was added to fat-free, high-protein samples (<0.3%, w/w, fat; 8%, w/w, protein) at different concentrations (0–4.4%, w/w). The gel properties were significantly influenced by the addition of MWP, due to the prevention of casein aggregation and creation of serum channels. The gels containing MWP had lower storage modulus, lower yield stress, lower firmness, higher porosity, lower tortuosity and lower water holding capacity compared with the control gel (without MWP).