Fabrication of whey protein isolate-sodium alginate nanocomplex for curcumin solubilization and stabilization in a model fat-free beverage

Abstract The present study aimed to fabricate whey protein isolate (WPI)-sodium alginate (ALG) nanocomplexes for curcumin (CUR) stabilization in a model fat-free beverage. Mass ratio of 5:1 at pH 5.0 in the absence of NaCl was optimized for WPI-ALG nanocomplex fabrication. Mean particle size and zeta-potential of CUR-WPI-ALG nanocomplex was 209.9 nm and −39.1 mV at pH 5.0, respectively. Highest loading amount (LA) of CUR in CUR-WPI-ALG nanocomplex were 15.26 μg/mg. No obvious precipitates were observed for CUR-WPI-ALG nanocomplex under simulated food processing and storage conditions including high sucrose, high NaCl, and thermal treatment at 90 °C for 2 h. Fluorescence results confirmed that the spontaneous interaction between CUR and WPI-ALG nanocomplex was primarily motivated by hydrophobic interaction and hydrogen bonding. Compared with CUR (free), chemical stability (UV light, and heat), and DPPH scavenging capacities of CUR in CUR-WPI-ALG nanocomplex were strikingly improved.