Fabrication of Hibiscus sabdariffa L. microparticles in Arabic gum and maltodextrin: multivariate optimization, chemometric analysis, simulated gastrointestinal digestion, and application as functional food ingredient

Hibiscus sabdariffa L. is a biomass source of phenolic compounds whose health benefits have been proven by various studies. This plant was extracted with aqueous alcohol (80%, v/v) and then encapsulated in microcapsules by spray drying method. The active ingredient was encapsulated in Arabic gum and maltodextrin. Combined optimal mixture design (COMD) with two mixture components (Arabic gum and maltodextrin) and a process factor (air inlet temperature) was used to construct the optimum formulation of the particles. Principal component analysis (PCA) was also applied to the experimental data as another multivariate statistical analysis. Furthermore, morphological (particle size distribution and particle shape) and physicochemical properties (moisture content, water activity, solubility, bulk density, tapped density, and Carr index) of the particles were analyzed. The optimum spray drying conditions were accessed using 190 °C and maltodextrin alone in order to obtain the highest responses (78.53% of encapsulation efficiency, 79.35% of encapsulation yield, 5.703 mg-TEAC/g-DM of antioxidant activity value, and 1.754 mg-C3G/g-DM of anthocyanin value). According to the in vitro release test for the bioactives from the particles, a release of 57.05% was detected in the simulated gastric fluid, whereas 50.38% of the phenolic substances were released in the simulated intestinal fluid. The functional properties (antioxidant activity and phenolic content) of the model food products (sunflower oil and corn oil) treated with the proposed particles were increased by ~ twice, while the stability against oxidation enhanced by almost 5%.