Moisture-Induced Aggregation of Alpha-Lactalbumin: Effects of Temperature, Cations, and pH

Alpha-lactalbumin is an important dairy protein ingredient, and has been widely used in high-protein foods such as infant formula and nutritional bars for its nutritional and functional properties. The purpose of this study was to investigate the moisture-induced aggregation ofalpha-lactalbumin in premixed protein dough model systems, and to illustrate the effects of temperature, cations, and pH on the progress of protein aggregation. Our results suggested that storage temperature was a critical factor for protein aggregation in model systems, and the formation of protein aggregates became faster with increases in storage temperature. Calcium significantly improved the thermal stability ofalpha-lactalbumin and slowed down the formation of protein aggregates. The increases in pH accelerated the aggregation ofalpha-lactalbumin. Our results also suggested that the formation of intermolecular disulfide bonds together with noncovalent interactions are the main mechanisms resulting in the moisture-induced aggregation ofalpha-lactalbumin in model systems.