Sensory characteristics and rheological properties of liquids thickened to International Dysphagia Diet Standardisation Initiative standards
This research identified and rated important perceived sensory properties of liquids thickened to levels in the International Dysphagia Diet Standardisation Initiative (IDDSI) framework, and related the identified textural attributes to rheological properties. Liquids thickened with modified cornstarch, xanthan gum, guar gum, and carboxymethyl cellulose were analysed via rapid and descriptive sensory methods, and characterized with a rheometer at shear rates ranging from 1 to 1000 s-1. Sensory attributes were categorized into taste and flavour, thickener specific, and thickness related attributes. Thickness related attributes were significantly different at different IDDSI levels within the same type of thickener, but they did not relate well to viscosity measurements. Further characterization showed that slipperiness was affected by type of gum and level of thickener, and that current recommendations for 50 s-1 as the oral shear rate are neither appropriate for approximating oral nor swallowing shear rates, with the latter likely occurring above 50 s-1.