Enhancing Physicochemical and Piezoelectric Properties of Eggshell Membrane Proteins by Ultrasonic-Assisted Enzymes for Food and Sensor Applications

This research sought to explore the impact of ultrasonic pretreatment on the physicochemical characteristics of proteins derived from eggshell membranes through enzymatic extraction. Response surface methodology (RSM) and Box-Behnken design were employed to identify the ideal conditions for the extraction process. The optimal parameters determined were enzyme usage at 4.2%, pH level at 2.4, a solid-to-solvent ratio of 1:20 g/mL, and an extraction time of 21.5 h. The eggshell membrane was pretreated by ultrasound before pepsin hydrolysis under optimized conditions. The findings indicated that the hydrolyzed products subjected to ultrasonic pretreatment exhibited enhanced solubility, surface hydrophobicity, water and oil retention, foaming characteristics, and emulsifying ability compared to the untreated hydrolyzed products. Furthermore, the piezoelectric properties of the protein with ultrasonic pretreatment were also significantly improved. Additionally, the protein-based piezoelectric device displayed excellent sensing performance and was successfully applied for human motion detection and precise identification of different pressure positions. These findings indicate that ultrasound has great potential to improve the physicochemical quality of eggshell membrane proteins, providing a theoretical basis and research approach for food protein modification and the preparation of green electronic devices.