The hydrogel of whey protein isolate coated by lotus root amylopectin enhance the stability and bioavailability of quercetin.

In this study, whey protein isolate (WPI)-quercetin (Que)-lotus root amylopectin (LRA) hydrogels (WPI-QUE-LRA) was developed to improve the solubility, stability and bioavailability of quercetin. Results showed that the favorable WPI-QUE-LRA was formed using WPI and LRA in the ratio of 1:2 at pH 7.0. Under this condition, the average size, polydispersity index, zeta potential of the WPI-QUE-LRA was 179.5 nm, 0.271, -18.6 mV, respectively. The analysis of transmission electron microscopy, fourier transform infrared spectroscopy and X-ray diffractometer revealed that the quercetin was successfully encapsulated in WPI-LRA, giving a high encapsulation efficiency of 92.4 %. Moreover, the WPI-LRA could significantly improve the storage stability and photochemical stability of quercetin. The in vitro and in vivo experiments showed that LRA-coated WPI hydrogel can enable quercetin to be stable in stomach and be effectively released in small intestine, leading to the enhancement of the bioavailability of quercetin.