Amyloid aggregation in mixed whey proteins

The fundamental principles behind the complexity of protein assembly, especially in mixed protein systems and crowded environments, remain elusive. This study provides molecular, structural, and viscoelastic insights into the aggregation and gelation processes in aqueous solutions of pure and mixed β-lactoglobulin and albumin whey proteins. To better understand protein aggregation in complex systems, we used a multi-technique approach that spans from molecular to macroscopic length scales. Our results show that, under low pH and heat denaturation, β-lactoglobulin tends to form ordered amyloid-type aggregates, while bovine serum albumin forms non-amyloid aggregates. In crowded environments, all protein solutions tested develop composite gel networks with distinct molecular origins. Here the ability to control the amyloid aggregate content, which has a substantial effect on the structural and viscoelastic properties of these composite gels, has been demonstrated. Gel structure and viscosity are crucial parameters to control for the food industry, as they play a key role in determining the softness and texture of food products. • Proteins behave independently of each other but form transparent composite gels. • Gels with higher amyloid content have higher viscosity. • Composite gels have tunable structural and viscoelastic properties.