Quantitative sensory interpretation of rheological parameters of a cream formulation

Abstract

As the popularity of a cosmetic product on the market extensively depends on consumers' perception, it is important for the sensory evaluation to be accurate during the product developmental stage. The focus of this study was to develop a generic method for the quantitative assessment of the sensory attributes of cosmetic creams. Four 100 g oil-in-water (O/W) model creams, containing loaded niosomes and their baselines (without niosomes), were formulated. Quantitative sensory evaluation of the formulated oil-in-water products were performed in three different stages: (a) appearance-pourability (b) pick-up-firmness and elasticity/stretchability (c) rub-out-spreadability and stickiness, using rheological measurements. All measurements were carried out at skin temperature, 32 ± 1 °C, and a relative humidity (RH) of 33%. The quantitative analysis showed all cream models exhibited shear-thinning, non-Newtonian behavior. Rheological parameters from the yield stress, amplitude sweep and frequency sweep tests were found to provide realistic correlations for the sensory characteristics of pourability and spreadability, firmness, elasticity/stretchability and stickiness, respectively. This novel quantitative assessment method of the sensory characteristics of a cream proved to be highly effective and can be universally applied.