Structure, Rheology and Organoleptic Properties of Starch Pastes - New Developments

Understanding consumer perception of the organoleptic qualities of a food product in terms of rheological properties is a major challenge for food scientists, and has been studied for a long time. As early as 1962 Szczesniak and Farkas (1962) reported a relationship between the mouthfeel of thickened solutions and their rheological behaviour. In this work, thickeners were categorised based on perceived sliminess (where a slimy liquid was defined as one which was thick, coats the mouth and was difficult to swallow). Of the thickeners investigated amylose (presumably a high amylose starch) and corn/maize starch were in the least slimy (best mouthfeel) category along with xanthan gum, whereas amylopectin (presumably waxy maize starch) was in the most slimy category. It was suggested that the mouthfeel improved with the extent of shear thinning. For example the high amylose and native maize/corn starches that gave the best mouthfeel were the most non-Newtonian, whereas waxy maize starch showed a behaviour that was closer to Newtonian. For this particular work the solutions used had the same viscosity at a shear rate that was probably much lower than the shear rate encountered in the mouth. For this reason, it could be argued that this early study only demonstrated that there could be a relationship between mouthfeel and the in-mouth viscosity.