Loading of anthocyanins on chitosan nanoparticles influences anthocyanin degradation in gastrointestinal fluids and stability in a beverage

The optimal preparation parameters to create anthocyanin-loaded chitosan nanoparticles was predicted using response surface methodology (RSM). A Box-Behnken design was used to determine the preparation parameters that would achieve the preferred particle size and high encapsulation efficiency. The result suggested that the optimized conditions were 2.86 mg/mL carboxymethyl chitosan (CMC), 0.98 mg/mL chitosan hydrochloride (CHC) and 5.97 mg anthocyanins. Using the predicted amounts, the experimentally prepared particles averaged 219.53 nm with 63.15% encapsulation efficiency. The result was less than 5% different than the predicted result of 214.83 nm particle size and 61.80% encapsulation efficiency. Compared with the free anthocyanin solution, the anthocyanin-loaded chitosan nanoparticles showed a slowed degradation in simulated gastrointestinal fluid. Compared with the free anthocyanin solutions in a model beverage system, the stability of the anthocyanins was increased in the anthocyanin-loaded chitosan nanoparticles.