Rheological Properties of Xanthan Gum of Different Intrinsic Viscosity and Mastication of Minced Carrots

Abstract

The relationship between the rheological properties of 0.6 wt % aqueous solutions of xanthan gum with different intrinsic viscosities and the palatability of the minced carrots with the xanthan gum was examined by steady shear viscosity, dynamic viscoelasticity measurements and sensory evaluation by the young panel. The intrinsic viscosities of xanthan gum A, B, C and D were 15.6, 16.0, 16.5, 20.0 dl/g, respectively. As has been reported previously, aqueous solutions of xanthan gum showed shear thinning flow and weak gel behavior. The storage modulus of xanthan gum D was larger than that of xanthan gum A. The young panel evaluated that minced carrots with xanthan gum D were thicker, of better mouthfeel, easy to be swallowed, and worse in taste than those with xanthan gum A. The aged panel judged that minced carrots with xanthan gum A were of better mouthfeel and easy to swallow than minced carrots without xanthan gum and cut carrots without xanthan gum. These results suggest that the rheological properties of xanthan gum make minced carrots easy to swallow. The aged panel who have natural teeth or wares partial dentures evaluated that minced carrots with xanthan gum A were easy to masticate, however the aged panel with full dentures judged that cut carrots were best to masticate, because minced carrots were too small to masticate. It was suggested that the condition of teeth might be important in the mastication of minced foods for the aged panel.