Nonlinear stress deformation behavior of interfaces stabilized by food-based ingredients

Interfaces stabilized by food-based ingredients, such as proteins or glycolipids, often display nonlinear behavior when subjected to oscillatory dilatational deformations, even at the lowest deformation amplitudes which can currently be applied experimentally. Here we show that classical approaches to extract dilatational properties, based on the Young-Laplace equation, may not always be suitable to analyze data. We discuss a number of examples of food-ingredient stabilized interfaces (interfaces stabilized by protein fibrils, protein-polysaccharide complexes and oligosaccharide-fatty aid conjugates) and show how an analysis of the dynamic surface tension signal using Lissajous plots and a protocol which includes deformation amplitude and droplet size variations, can be used to obtain a more detailed and accurate description of their nonlinear dilatational behavior.