Influence of hydrodynamic cavitation on functional, nutritional, and structural characteristics of egg-white protein hydrolysates

The present work demonstrates the effect of hydrodynamic cavitation (HC) (2 mm Orifice plate) as a pretreatment for egg white protein hydrolysates (EWPH) production. The obtained EWPH was evaluated for various physiochemical (degree of hydrolysis), functional (emulsifying, foaming), structural and nutritional properties (antioxidant activity and in-vitro digestibility). The egg white solutions (5% solid content) were pretreated for 10, 15 and 20 min with HC and later hydrolyzed using papain enzyme for 90 min. The structural analysis revealed that HC unfolded the protein structure which was confirmed through the formation of β-sheet (from 15 to 46%) and loss of α-helix (34 to 14%) content with increasing treatment time. Through the exposure of hydrophobic bonds, the degree of hydrolysis and surface hydrophobicity increased, which eventually improved the nutritional and functional properties of EWPH. The HC-15 min treated samples had the highest zeta potential (-25.4 mV) with the lowest average particle size (346.5 nm) and denaturation temperature (70.67°C). Further increase in treatment time led to instability of hydrolysates. HC effectively improved the functional and nutritional properties of EWPH and a treatment time of 15 min is recommended for obtaining EWPH with improved properties.