Rheological, Textural and Flavour Properties of Yellow Mustard Sauce as Affected by Modified Starch, Xanthan and Guar Gum

Influence of a modified starch-gum thickening system on the rheological, textural and flavour properties of yellow mustard sauce was studied. The rheological measurements indicated that the sauces exhibited a weak gel-like, strong shear thinning behaviour. Dynamic viscoelasticity measurements showed that the sauces with modified starch (MS) and xanthan gum (XG) presented superior viscoelastic properties to those with MS and guar gum (GG) samples. All tested sauces showed non-Newtonian, pseudoplastic and thixotropic fluids characteristics. Parameters such as hardness, springiness, cohesiveness, gumminess and spreadability were used to evaluate the textural properties, and the results indicated that MS/XG was more influential than MS/GG on the textural properties. Sensory analysis suggested that 0.4 % MS/0.3 % XG, 0.4 % MS/0.4 % XG and 0.4 % MS/0.4 % GG were superior thickeners for the yellow mustard sauces. The flavours of these three sample groups with the highest sensory scores and a sample with only MS were analysed by an electronic nose, which showed that the electronic nose was able to distinguish their differences

Moisture absorption characteristics of food thickeners used for the management of swallowing dysfunctions

Six commercial food thickeners, based on starch, and guar and xanthan gums, were investigated for their moisture absorption properties. The thickeners were exposed to 100% relative humidity as well as soaked in water for selected time periods. The gum-based thickeners dissolved in water to yield 100% water solubility index. The water absorption index of the starch-based thickeners ranged from 14.7 to 18.0 g/g dry solids of thickener. The starch-based thickeners sorbed less moisture than the gum-based ones, with the xanthan gum-based thickeners having the highest sorptive ability on mass basis. The Peleg model was the most suitable (r(2)=0.966-0.997) of the sorption models investigated to describe the sorption data. The diffusion rate constant of the thickeners ranged from 8.7 to 13.5 day%(-1), while the equilibrium moisture content was between 35.7 and 46.8%. The sorptive ability explained viscosity development in some of the thickeners, but was unsuitable in fully describing comparisons of the solutions viscosities of starch-based and xanthan gum-based thickeners