Effect of xanthan gum on lipid digestion and bioaccessibility of β-carotene-loaded rice starch-based filled hydrogels

The aim of this study was to examine the effects of xanthan gum on the lipid digestibility, rheological properties, and beta-carotene bioaccessibility of rice starch-based filled hydrogels. beta-Carotene was solubilized within lipid droplets of emulsion that were then entrapped within rice starch hydrogels fabricated with different concentrations of xanthan gum. At a low concentration of xanthan gum (< 0.5 wt%), the viscous characteristics of the filled starch hydrogels increased. Furthermore, these hydrogels had a slower rate of lipid digestion than the beta-carotene-loaded emulsion. As the concentration of xanthan gum was increased (to 1.0 wt% and 2.0 wt%), the filled starch hydrogels became more elastic gel-like than those without xanthan gum, and also had the fastest rate and highest final extent of lipid digestion. The addition of xanthan gum to the filled starch hydrogel lowered the bioaccessibility of beta-carotene to varying degrees, depending on the xanthan gum concentration. The results obtained from this study can be useful in designing gel-like food products fortified with lipophilic nutraceuticals.