Nanocomplexes composed of chitosan derivatives and β-Lactoglobulin as a carrier for anthocyanins: Preparation, stability and bioavailability in vitro.

To improve sustained-release property, stability and bioavailability of anthocyanins (ACNs) in vitro, we fabricated the nanocomplexes with chitosan hydrochloride (CHC), carboxymethyl chitosan (CMC) and β-Lactoglobulin (β-Lg). Response surface methodology (RSM) combined with desirability function was employed to optimize ACNs-loaded chitosan/β-Lg (CHC/CMC expressed with chitosan) nanocomplexes with maximum anthocyanins retention rate, preferred particle size and high encapsulation efficiency. The result suggested that the optimized conditions were 5.16 mg/mL of β-Lg, 1.45 mg/mL of CMC and 6.09 of pH CMC solution. Based on optimized conditions, anthocyanins retention rate, particle size and encapsulation efficiency of ACNs-loaded chitosan/β-Lg nanocomplexes were 68.9%, 91.71 nm and 69.33%, respectively. ACNs-loaded chitosan/β-Lg nanocomplexes was more stable in simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 6.8) by showing less ACNs release (%) than that ACNs solution and ACNs-loaded CHC/CMC nanocomplexes. Further, stability and bioavailability of ACNs in simulated gastrointestinal (GI) tract were significantly improved by nanocomplexes encapsulation. Compared with ACNs-loaded CHC/CMC nanocomplexes, ACNs-loaded chitosan/β-Lg nanocomplexes displayed better sustained ACNs release, stability and bioavailability.