Curcumin-loaded nanoparticles developed from sodium caseinate and OSA starch and the <i>in vitro</i> semi-dynamic elderly digestion behaviour of fortified yogurt

Abstract Curcumin is a bioactive substance, while poor stability and low bioavailability limit its effective utilisation. Curcumin-loaded nanoparticles were prepared using the wall materials containing OSA starch alone (HI), sodium caseinate alone (SC), and a mixture of OSA starch and sodium caseinate (HS). Compared to HI and SC, HS had obvious network structure and smaller particle size, with the loading capacity higher than 20%. The storage stability at 4 °C were higher in HS and SC, FTIR and XRD results showed that all nanoparticles encapsulated curcumin through hydrogen bonding. When nanoparticles were added to yogurt, HI showed slower curcumin release during in vitro semi-dynamic elderly digestion, whereas SC and HS can better accelerate the digestion rate of proteins in yogurt, leading to a decrease in the apparent viscosity of digestive emptying products. This study provided a reference for curcumin delivery wall materials and pushed forward development of functional foods for elderly.