Stability and in vitro digestion simulation of soy protein isolate-vitamin D3 nanocomposites.

Nanocomposites were prepared with soy protein isolate and vitamin D 3 (SPI-VD 3) as raw materials under high-pressure homogenization conditions to study their stability and in vitro digestion. Various nanocomposites of SPI and VD 3 combined with high-pressure homogenization and carboxymethyl chitosan (CMC) were analyzed. The average particle size of SPI decreased from 384.4 nm to 82 nm after VD 3 addition and high-pressure homogenization. When CMC was added for ion crosslinking, the average particle size increased to 85 nm. After 4 h of UV irradiation, the content of VD 3 was 48% after high pressure homogenization, which was three times higher than that of pure VD 3. In the simulated in vitro digestion process, the content of pure VD 3 in gastric juice was 0.568, while the release rate of VD 3 in the CMC (SPI-VD 3) h sample was only 0.133, thus achieving the effect of sustained release. Fourier infrared results showed that hydrogen bonding was also an important interaction between SPI and VD 3. In sample CMC (SPI-VD 3) h, CMC and Ca2+ showed strong electrostatic interactions and were cross-linked. • Homogenization can significantly improve the load rate of SPI-VD 3. • The content of VD 3 was increased after light stability after homogenization. • CMC(SPI-VD 3)h can reduce the decomposition rate of VD 3 in vitro digestion simulation. [ABSTRACT FROM AUTHOR]