Construction of W/O/W microcapsules based on the combination of polyglycerol polyricinoleate/protein for the co-encapsulation of crocin and quercetin: Physical properties, stability and in vitro digestion.

Due to health reasons of polyglycerol polyricinoleate (PGPR), there has been a growing interest in reducing it. To address this, this study developed the PGPR/Protein (whey, pea, and chickpea protein isolates) emulsifier combinations. The effects of these combinations on the preparation, structure, physicochemical and in vitro digestive properties of W/O/W microcapsules were evaluated. The FTIR and XRD analyses revealed hydrogen bonding interactions between the protein and PGPR (or bioactive compounds), which may contribute to the enhanced encapsulation efficiency (EE) and stability of microcapsules. PGPR/pea protein isolate (PP) microcapsules exhibited more uniform size, better rehydration, and higher EE than other microcapsules. PP combinations prolonged shelf-life of microcapsules by 1.35 to 1.73-fold, as predicted by oxidation kinetic models. Furthermore, PP microcapsules improved the bioavailability of crocin (≥ 11.08 %) and quercetin (≥ 8.47 %). Overall, this study hoped to provide a promising strategy for preparing W/O/W microcapsules with low PGPR content.