Controlled aggregation of whey protein toward the exceptional tolerance of high ionic strength upon heating

Ready-to-drink whey protein beverages featuring electrolyte replenishment and whey protein intake are experiencing increasing popularity in the market for sports nutrition. However, such preference was challenged by NaCl-promoted thermotropic gelation. In this study, whey protein aggregates (WPA) with improved tolerance to NaCl-promoted thermal aggregation were successfully fabricated by regulating pH and protein concentration during preheating modification. The suspension was clear and had good flowability after heating 30 min at 100 °C in the presence of 100 mM NaCl, even at WPA concentration of 7 %. This heightened tolerance was ascribed to the enhanced structural compactness and elevated absolute zeta potential, as evidenced by combing dynamic light scattering, rheology, transmission electron microscopy, and intrinsic fluorescence analysis. Given these findings, this study provided an effective strategy to mitigate the thermal aggregation behavior of whey proteins in NaCl-containing systems, contributing to the industrial production of electrolyte-fortified whey protein beverages.