Novel Attempt for Quantitative Sensory Evaluation of Cosmetics using the Nutting Parameters

Texture of the cosmetic products is an important factor for the consumer satisfaction. It is considered that the texture is originated from various physical properties. However, since the phenomena are very complicated, to appropriate quantification is difficult. Our attempt is to quantify the texture of the initial touch of the cosmetics by studying the rheological properties. Flow properties of cosmetic lotions, containing various kinds of aqueous thickeners, were studied by creep measurement, and parameters α, β, and φ, were calculated from their rheological data based on the Nutting equation, which is an empirical equation. As another approach, sensory evaluation test of the cosmetic samples was carried out by human panels. There were some correlations among the time dependency parameter α and some sensory evaluation points, assessed by human panels. Simple linear regression analysis revealed that the evaluation scores of slimy feeling, sticky feeling, refresh feeling, and penetrating feeling of the cosmetic lotions were converted to numerical data by the parameter α. This quantification method for the texture of cosmetic products will be a useful tool for efficient development of cosmetic formulations. It is possible to estimate the texture of the products by studying the rheological value α