Ultrasound-driven structural remodeling of coconut protein isolate: mechanisms of aggregation control and gel network...

Coconut protein isolate (CPI) exhibits weak thermogel properties, limiting its industrial development. In this study, we investigated the use of ultrasonic-assisted modification (100-500 W, 10-30 min) to regulate the structure, aggregation, and gel characteristics of coconut protein isolate. Low-field magnetic resonance imaging (LF-NMR), scanning electron microscopy (SEM), and rheological techniques revealed that ultrasonication optimized the order of β-sheets and α-helices, increased water retention capacity, and enhanced ionic and hydrophobic interactions (75.50 %). At 300 W and 20 min, the gel exhibited uniformly dense pores, 37 % increased water retention, and a storage modulus (G') of 91,006.211 Pa. Excessive power (>300 W) or duration (>20 min) caused protein over-aggregation, leading to network collapse. These findings demonstrate that ultrasound can enhance CPI gels and provide insights for structural design in plant-based foods.