Oral Shear Stress Predicts Flavour Perception in Viscous Solutions

Abstract

The perception of sweetness and flavour were studied in viscous solutions containing 50 g/l sucrose, 100 p.p.m. iso-amyl acetate and varying concentrations of three hydrocolloid thickeners (guar gum, lambda-carrageenan and hydroxypropylmethyl cellulose). Zero-shear viscosity of the samples ranged from 1 to 5000 mPas. Perception of both sweetness and aroma was suppressed at thickener concentrations above c* (coil overlap concentration, the point at which there is an abrupt increase in solution viscosity as thickener concentration is increased). Sensory data for the three hydrocolloids was only loosely correlated with their concentration relative to c* (c/c* ratio), particularly above c*. However, when perceptual data were plotted against the Kokini oral shear stress (tau), calculated from rheological measurements, data for the three hydrocolloids aligned to form a master-curve, enabling the prediction of flavour intensity in such systems. The fact that oral shear stress can be used to model sweetness and aroma perception supports the hypothesis that somatosensory tactile stimuli can interact with taste and aroma signals to modulate their perception.

Effect of hydrocolloid on rheology and microstructure of high-protein soy desserts

“…4c, d). The good correlation obtained between the two index values (R 2 = 0.92) seems to confirm the practical utility of both of these instrumental measurements to predict perceived consistency or thickness in this type of semisolid product (Cook et al 2003;Arancibia et al 2013b).…”

“…However, some authors have found that oral thickness correlates with different rheological indices. It has been confirmed that one of them, apparent viscosity at a shear rate of 50 s −1 , suggested by Wood in 1968, has practical utility as a possible instrumental index of thickness perceived in semisolid foods (Cook et al 2003;Arancibia et al 2013b). Consequently, apparent viscosity values at a shear rate of 50 s −1 (η 50 ) were also calculated.…”

Aroma encapsulation and aroma delivery by oil body suspensions derived from sunflower seeds (Helianthus annus)

“…Cook [21] looked at the effect of physical properties on retronasal flavour release and showed that the viscosity of a consumed solution did not affect retronasal flavour delivery. Cook hypothesized, within the study, that it was the interfacial properties of the solution that are most significant in controlling flavour concentration retronasally.…”

Relationship between Food Rheology and Perception

“…In a comprehensive study, Cook et al (2003) investigated the relationship between various viscosity-related parameters and taste perception and found the strongest dependence on the Kokini oral shear stress defined by Equation 8.1. Of course, a viscosity dependence of perception must result from the relationship shown in Fig.…”