Influence of oleogel composition on lipid digestibility and β-carotene bioaccessibility during in vitro digestion

Abstract

This study explored how co-oleogelator type, concentration, and water addition affect lipid digestion and β-carotene (βC) bioaccessibility in corn oil oleogels. Oleogels containing 0.1% βC, 20% glyceryl stearate (GS), with lecithin (L) or hydrogenated lecithin (HL) (at 0, 0.5, or 2.5%) and their water-filled counterparts (1% water) were examined. In vitro intestinal digestion revealed HL-oleogels experienced higher lipolysis due to their smaller crystal size enhancing surface area for lipase action, whereas L-oleogels presented lower digestibility, attributed to larger oil droplets and a minimized surface area. Water addition didn't significantly change lipid digestibility. βC bioaccessibility was inversely related to co-oleogelator concentration, with L-oleogels demonstrating the largest decrease, likely due to less free fatty acids released for micelle formation. However, water-filled oleogels enhanced βC bioaccessibility. These findings highlight that tailored microstructure in oleogels can control lipid digestion and βC bioaccessibility, paving the way for designing efficient delivery systems for targeted nutrient delivery.

Keywords: Bioaccessibility; Glyceryl stearate; In vitro digestion; Lecithin; Oleogel; β-Carotene.