Whey protein concentrate (WPC) was hydrolyzed by trypsin and Protease M from Aspergillus oryzae. Structure and functionality of WPC, hydrolysates, and a whey co-product, Procream, were evaluated for their impact on emulsion stability. Emulsification properties and antioxidant activity of hydrolysates were uniquely impacted by the type of enzyme and the degree of hydrolysis. The physical stability of the emulsions, assessed by turbidity and particle size, and the oxidative stability, assessed by measuring peroxides, were related to physiochemical characteristics. Trypsin hydrolysis significantly decreased surface hydrophobicity, by preferentially targeting β-lactoglobulin, and increased zeta potential, resulting in enhanced water solubility. Hydrolysis improved/maintained emulsification properties and enhanced antioxidant activity. In fish oil emulsions, a synergistic effect on both physical and oxidative stability was observed when combining hydrolysates and Procream. Trypsin hydrolysate + Procream emulsion demonstrated the best oxidative stability. Results demonstrated a successful approach to valorize a whey co-product for targeted emulsion applications.
Bibliographical noteFunding Information:
This project was generously funded by Midwest Dairy Association ™. The authors acknowledge Professor Gary Reineccius for suggestions regarding emulsion making and stability testing, and Professor Stephan Drusch at TU Berlin for assistance with the LOOH method and allowing the use of his equipment to develop the method for emulsion formation.
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