Structure, rheology and gastrointestinal release kinetics of new-type curcumin-based nanofibers nanohydrogel assisted prepared with subcritical water at different treatment times

This study aimed to design a new-type curcumin (Cur)-based network nanohydrogel (H), which was composed of whey protein isolate nanofibers (WPINs) and pectin (P). Among them, WPINs were prepared with subcritical water at different treatment times (90 min: WPINs-90, 120 min: WPINs-120, and 180 min: WPINs-180). The structural characteristics, rheology and gastrointestinal release kinetics of Cur-based nanohydrogel were investigated. The results showed that WPINs-120-P-H showed the most favorable particle size (659.00 ± 3.90 nm), potential (−30.00 ± 2.00 mV), peak temperature (110.57 °C) and heating stability. The rheological results revealed that each group of nanohydrogels formed strong elastic gels. In addition, WPINs-120-P-H exhibited the highest encapsulation efficiency (98.42 ± 5.00%) of Cur with the strongest network structure. Moreover, the release curved line of Cur showed an initial release of 19.23% in the stomach, and afterwards, a continuous release trend in the small intestine, reaching a final release amount of 84.80%. Interestingly, the release kinetics of Cur was in line with the Weibull equation model, evidencing a continuous and dynamic release process. This study provided a novel way to prepare the WPINs-P nanohydrogel as delivery for Cur, which demonstrated great potential application prospects in the functional food industry.