Effect of xanthan gum on palm oil in vitro digestion. Application in starch-based filling creams

Abstract The purpose of this study was to investigate the influence of xanthan gum (XG) on the structural changes of palm oil during in vitro digestion and to evaluate the application of the XG-palm fat system in filling creams. The textural, rheological and microstructural properties were studied in three systems: a XG-palm fat system, a filling cream with the XG-palm fat system, and a control filling cream with palm oil but without xanthan gum. Free fatty acids were measured at the end of the in vitro digestion as indicators of fat digestion and related with the structural changes. The incorporation of palm oil inside the xanthan gum matrix significantly reduces fat digestion. In comparison to the control cream, the microstructure reveals the presence of undigested fat when XG is present at the end of intestine in vitro incubation, while the presence of fat was significantly reduced in the control cream. After stomach incubation, an increase in the extrusion force and in the elastic and viscous modulus was observed in the xanthan gum systems, this was despite the greater water dilution, which was associated with an increase in fat globule size. In the control cream, a decrease in viscoelasticity is observed after stomach incubation. The results of the present research may have applications in the design of low-fat food and in applications where stomach content structuring is desired.