Understanding the role of native and pre-gel starches in the stabilization mechanisms of egg white foams produced by aeration and microwave dehydration

• Insights into how starch type affects egg white-based foam stability • Liquid foam stability strongly impacts microwave processing and the final structure • Microwave stage behavior depends on starch size, corn starch gives better integrity • Pregelatinized starch boosts foaming and yields the best-performing samples Egg white foams are prevalent in the food industry due to their unique properties. In this study, we investigate the impact of adding native and pregelatinized starches from different crops, potato and corn, on the density and structural parameters of egg white foams. A two-step foaming process based on liquid aeration and microwave dehydration is used to produce the foams. The addition of starch and potential synergetic effects with the proteins in egg white is found to influence the foam's structural integrity. The use of native corn starch allowed to obtain foams with lower densities-158 kg/m 3 - and more homogeneous cellular structures with lower cell sizes than the reference one based on egg white. The largest density reduction is found with pre-gel starches, allowing the production of foams with densities close to 100 kg/m 3 and cell sizes lower than 300 µm. Our research aims to elucidate the stabilization mechanisms of these starches through a novel and comprehensive analysis of the foams in the two steps of the process. Both the liquid and dehydrated foams are extensively characterized by density measurements, by image analysis to quantify both the gas phase distribution and the solid phase distribution, by viscosity measurements, and by drainage measurements.