Macromolecular properties and interactions of proteins and polysaccharides determine the rheology of real and vegan food formulations

Proteins and polysaccharides frequently coexist in biological systems, and many food formulations that substitute animal-based proteins with vegan, plant-sourced alternatives incorporate polysaccharides as rheology modifiers. The extensional rheology response of these formulations is known to be highly associated with mouthfeel and consumer perceptions of texture, thickness, stringiness, and stickiness. Thus, assessing the roles played by macromolecular phenomena (e.g., complexation, aggregation, adsorption) as well as pH/salt in determining the response to stretching flows is critical in the design of sustainable food formulations. However, quantitative measurements of responses to streamwise velocity gradients for these complex systems has been a longstanding challenge. In this talk, we select proteins and polysaccharides used in several vegan food foams and emulsions, and characterize their pinching dynamics and extensional rheology using dripping-onto-substrate (DoS) rheometry. We elucidate how complexation transforms the perceived stringiness and both shear and extensional rheology response.