Fish skin gelatin-based emulsion as a delivery system to protect lipophilic bioactive compounds during in vitro and in vivo digestion: The case of benzyl isothiocyanate

Abstract

To improve the stability of nutrients in the gastrointestinal tract, fish skin gelatin (FSG) was used as an emulsifier and benzyl isothiocyanate (BITC) as a model of nutrient delivery to construct a stable emulsion. Tween-based emulsions were used as controls. The emulsion stability, lipid digestion, and BITC bioavailability were investigated using a simulated gastrointestinal tract model. The in situ single-pass intestinal perfusion model was used to calculate the absorption (Ka) and effective intestinal permeability (Peff) of each sample. After digestion in the stomach, the emulsions had obvious aggregation, as shown by atomic force microscope, confocal laser scanning microscopy and cryo-scanning electron microscopy images. The release of free fatty acids from the FSG-based emulsion reached 87.5 ± 1.45% during the small intestinal digestion. The bioavailability of BITC in the FSG-based emulsion was 80.77%, which was nearly 27% higher than that of the control. At 120 min, Ka and Peff of the FSG-based emulsion reached the maximum values of 10.15 × 10−3/min and 6.48 × 10−3 cm/min, respectively, suggesting that the FSG-based emulsion could protect BITC and achieve a sustained release effect. These results show that the FSG-based emulsion delivery system is effective in encapsulating, protecting, and delivering BITC.