Nanoencapsulation of Sea Buckthorn Polyphenols (Hippophae rhamnoides L.) in Milk Proteins for Targeted Delivery to the Lower Gastrointestinal Tract

In this study, sea buckthorn polyphenols (SBP) were nanoencapsulated in casein and whey proteins to safeguard them from harsh gastrointestinal conditions. Encapsulation efficiencies of 69 and 75% were observed for CPM (SBP-loaded casein nanoparticles) and WPM (SBP-loaded whey protein nanoparticles), respectively. Field emission scanning electron microscopy (FESEM) images revealed spherical particles with some cavities where polyphenols were embedded. Fourier transform infrared (FTIR) spectra confirmed the inclusion of SBP in casein and whey protein nanoparticles. The particle sizes of CPM and WPM were 510.16 and 789.25 nm, respectively, and their low PDI revealed uniformity in size. Peak denaturation temperatures of CPM and WPM were 64.20 and 54.89 degrees C, respectively. SDS-PAGE revealed improved digestibility in CPM and WPM. Bioactivity retention of nanoparticles and free SBP upon simulated digestion was accessed in terms of antioxidant, antidiabetic, and antiobesity activities. Results revealed high bioactivity in CPM and WPM compared to free SBP.