Abstract: Hawthorn pectin was prepared by acid extraction followed by ethanol precipitation and purified by enzymatic hydrolysis before being used to construct hawthorn pectin-zein composite nanoparticles. The lycopene encapsulation and delivery efficiencies of the nanoparticles were systematically evaluated. The results indicated that after enzymatic hydrolysis, the degree of esterification (DE) of hawthorn pectin reduced from 73.87% to 39.04%, the galacturonic acid (GalA) content increased from 53.01% to 85.68%, and the microstructure was more fragmented, forming a distinct fibrous network. The composite nanoparticle prepared with the purified pectin at a concentration of 0.6 mg/mL and a mass ratio of lycopene to zein of 1:10 showed the smallest particle size of 613.3 nm, the highest lycopene encapsulation efficiency (80.01%), and the highest absolute zeta potential value (-32.40 mV), and its core-shell structure was relatively stable. Compared with the nanoparticle prepared with hawthorn pectin not subjected to enzymatic hydrolysis, the dispersion stability increased by over 20%, and the release rate of loaded lycopene in the intestinal tract by more than 15%. These results provide ideas and data references for developing and applying pectin-protein composite carriers for efficient delivery of natural bioactive compounds in foods.

Key words: hawthorn pectin; zein; nanoparticle delivery system; lycopene; intestinal release efficiency