Ultrasound-assisted alkaline hydrolysis of fish(Cyprinus carpio L.) scale gelatin: A possible curcumin delivery system with increased water solubility and sustained release
Jia Liu, Haoxin Li, Wan Aida Wan Mustapha, Xiaoping Zhang
Abstract
This study investigated the effect of ultrasound-assisted alkaline treatment on the structural characteristics and curcumin loading efficiency in fish scale gelatin (FSG). The results showed that FSG treated with a combination of ultrasound and alkaline hydrolysis outperformed non-treated FSG, as well as alkaline- or ultrasound-treated FSG in augmenting curcumin loading efficiency (from 3.02 to 18.36 μg/mL). In contrast to FSG exposed to single treatments (alkaline or ultrasound), the FSG subjected to combined treatment exhibited a notably higher ratio of hydrophobic amino acids (47.51 ± 2.27%) and protein elution amount (180.87 μg/mL). Meanwhile, single and combined treatments significantly modified the molecular conformation as well as the microstructure of FSG, transforming the α-helical conformation to the β-sheet structure and presenting an ordered structure with increased voids. The curcumin-loaded FSG subjected to ultrasound-assisted alkaline treatment revealed a sustained release profile under simulated gastrointestinal conditions. The elucidated outcomes underscore the significant potential of FSG subjected to ultrasound-assisted alkaline treatment as a promising avenue for facilitating the controlled delivery of bioactive hydrophobic nutrients.