Investigation of the interaction of large yellow croaker Pseudosciaena crocea roe protein isolate with curcumin and its effect on the gastrointestinal fate of curcumin through protein hydrogels

Abstract: In this study, the large yellow croaker (Pseudosciaena crocea) roe protein isolate (pcRPI) and the heated pcRPI (HpcRPI) with Cur complex and their cold-set gels were prepared, and the effects of heat treatment on the binding mechanism of protein with Cur were also investigated. The fluorescence spectroscopy, UV‒visible absorbance spectra, Fourier transform infrared spectroscopy and surface hydrophobicity results indicated that p<span style="font-family: 'Times New Roman';">cRPI and HpcRPI bind with Cur mainly by van der Waals interactions, hydrophobic interactions and hydrogen bonds, and compared with p<span style="font-family: 'Times New Roman';">cRPI, HpcRPI showed better binding effects with Cur. Molecular docking analysis also evaluated the binding site and the forces between vitellogenin and vitellogenin B and C in pcRPI with Cur. Furthermore, HpcRPI-Cur could form cold-set gels induced by 0.2% Glucono-δ-lactone (GDL) with a higher G’ value, while pcRPI-Cur-GDL still showed a fluid state. The HpcRPI-Cur-GDL gels could protect 60% Cur to the colon, showing an excellent delivery effect. These results indicated that heat treatment will improve the application of pcRPI as a functional material in the food industry.