In vitro digestibility and bioaccessibility of lipid-based delivery systems obtained via enzymatic glycerolysis: a case study of rosemary extract bioaccessibility

Abstract

This work studies the effect of enzymatic glycerolysis on digestibility and bioaccessibility of ratfish liver oil (RLO) rich in alkylglycerols (AKGs), as well as the capability of the glycerolysis product (GP) to act as lipid-based delivery system (LBDS) for a supercritical rosemary extract. For comparison purposes, digestibility and bioaccessibility of two additional lipid systems i.e. original RLO and RLO with addition of GRAS monoolein (MO) as emulsifier agent (RLO + MO), have been evaluated. We have studied the efficiency of the GP and RLO + MO lipid systems as LBDS by combining them with a supercritical rosemary extract (RE), i.e. RE lipid-based formulations. In vitro digestibility and bioaccessibility of un-loaded lipid systems, RE lipid-based formulations and un-carried RE have been determined. The results show a higher digestibility and bioaccessibility of the GP as compared to those of original RLO and RLO + MO. Likewise, a substantial improvement of RE bioaccessibility has been observed when GP is used as lipid carrier of RE. The present work demonstrates that enzymatic glycerolysis is an efficient strategy to obtain highly bioaccessible and potentially bioactive alkylglycerol-based delivery systems, which can be used to increase the bioaccessibility of low water-soluble bioactive compounds.