Construction and stabilizing mechanism of nano starch-whey protein composite nanoparticles based high internal phase...

This study utilized sweet potato starch (SPS) as the research material and prepared nano starch (NS) particles with an average diameter of 4.9 nm through enzymatic debranching and starch rearrangement treatment. Under hydrothermal and recrystallization treatment, the NS particles and whey protein (WP) were mixed to prepare NS-WP composite particles, which were further used to prepare NS-based high internal phase Pickering emulsion. The relevant structural and physicochemical tests were performed on NS, NS-WP and NS-WP Pickering emulsions, and the results showed that NS and WP were complexed through hydrophobic interactions and hydrogen bonding. The introduction of a small amount of WP (1 %-13 % based on complex weight), which was mostly coated on NS surface, changed the particle morphology, increased the particle size (from 4.9 nm for NS to 25.6 nm for NS-WP-13), and enhanced the hydrophobic properties of NS (with the contact angle increasing from 79.00° for NS to 110.24° for NS-WP-13). These changes significantly improved the emulsification index (EI, from 92.13 % for NS-WP-1 to 100 % for NS-WP-13), storage stability (with the loss of EI decreasing from 7.89 % to 0 %), and centrifugal stability of the resulting Pickering emulsion. The NS-WP based Pickering emulsions offer advantages such as environmental friendliness, high emulsification index, and excellent stability. The successful preparation of NS-WP composite particle-stabilized Pickering emulsions provides a clean-label approach for the high-value utilization of SPS and demonstrates its potential in constructing high internal phase emulsion systems, offering a reference for further exploration of colloidal delivery systems based on modified SPS.