Bigels as capsaicin and gallic acid co-delivery systems: Controlled release and enhanced bioavailability

With the evolving lifestyles and diets, natural bioactives with excellent nutritional value and specific health benefits are attracting increased attention. In this study, a bigel constructed by glycerol monolaurate (GML) and low acyl gellan gum (LA) was used as the co-delivery system to protect capsaicin (CAP) and gallic acid (GA). The results showed that CAP and GA in bigel exhibited higher stability than free ones. After 12 days at 4 degrees C, the retention rates of CAP and GA in bigel were 71.13% and 83.34%, respectively, which increased by about 25.91% and 49.32% compared to that of free ones. In vitro digestion showed that the bigel exhibited significant controlled and sustained-release effects on CAP and GA. At the end of simulated intestinal digestion, >40% and 30% of CAP and GA were still not released from bigel. In the Caco-2 cell monolayers model, CAP and GA are mainly absorbed and transported by passive diffusion, and their bioavailabilities were increased by 1.35- and 1.77-fold compared to individually entrapped systems. Therefore, the stability and bioavailability of CAP and GA can be improved by co-encapsulating with GML-LA bigel.