Emulsion stabilization by sustainable yeast proteins from Saccharomyces cerevisiae: Influence of pH value and oil content

This study investigates the potential application of alternative proteins from baker's yeast in food emulsions, examining how oil content and pH affect emulsion microstructure and stability. Emulsions were prepared at pH values of 3, 5, and 7, with oil contents up to 50 wt%. Measurement techniques like zeta potential, SDS-PAGE, light scattering, microscopy, and rheometry were used for characterization. At pH 5, partitioning occurred immediately after preparation, while at pH 3 and 7, emulsions appeared homogeneous. Droplet size and microscopic analysis showed different microstructures of the emulsions: individual droplets at pH 7, dense flocs at pH 5, and loosely packed flocs at pH 3. pH-induced aggregation and unfolding of the protein molecules due to acid treatment were key factors influencing the oil droplet structuring and therefore the emulsion stability. The study shows that yeast proteins can stabilize high oil-content emulsions and they offer a pathway for developing novel, eco-friendly emulsifiers for the food industry.