Potential of Microbubbles as Fat Replacer: Effect on Rheological, Tribological and Sensorial Properties of Model Food Systems

The potential of microbubbles as fat replacers and texture modifiers was assessed by comparison of the rheological and tribological properties of model food systems that contained (1) microbubbles, (2) emulsion droplets or (3) no added colloidal structures. We used (a) liquids with thickener, (b) liquids without thickener and (c) gels as model food systems. A sensory test was performed in which we investigated whether panellists could discriminate between the different samples. It was found that the food system containing emulsion droplets had better lubrication properties than the dispersions containing microbubbles and solutions without any colloidal structures. The systems with emulsion droplets could be well discriminated sensorially from those with microbubbles or those without an added colloidal structures. Samples containing a mixture of emulsion droplets and microbubbles were comparable to those of samples containing only emulsion droplets. We conclude that at the studied volume fraction of 5% the measured friction and perceived mouthfeel of systems containing microbubbles is rather different from those of systems containing emulsion droplets, while both have a diameter of about 1 m. At this volume fraction microbubbles cannot simply replace emulsion droplets. Practical ApplicationsMicrobubbles may have practical applications in food products as texture modifiers and fat replacers, and can be therefore considered as new colloidal structures with a potential in the development of healthier food products. Combining rheological, tribological, and sensorial experiments is a useful tool to test the application of new ingredients in food products and to understand their working mechanisms. This study represents an example of this approach to assess the potential of new colloidal structures as food ingredients. The combination of rheology and tribology with limited sensory experiments allows to estimate this potential without the need of extensive sensory studies that would require large amounts of samples, which in the case of systems containing microbubbles would be also extremely expensive.