Investigation of Apparent Skin Tension

Abstract

Skin tension, “hari”, is one of the factors of ideal skin. “Hari” is often considered to be a mechanical property such as skin elasticity and most researchers have focused on the dermis to improve it. However, we hypothesized that“ hari" has a visual factor in addition to a tactile one and thus we focused on it in this study. By cluster analysis using data of sensory evaluation on Japanese female facial skin, we found that apparent “hari" was very close to apparent moistness, while it were classified under a different cluster from tactile “hari”. Apparent “hari” correlated with both water contents of the stratum corneum and transepidermal water loss. Because these results suggest that the improvement of the water conditions of the stratum corneum may lead to enhancing apparent “hari”, we applied moisturizing products for female facial skin to investigate whether the scores of apparent “hari” improved when the stratum corneum water conditions were improved. As a result, water contents of the stratum corneum and apparent “hari” were both significantly improved, while there was not a significant change in tactile “hari”. Our results suggest that apparent “hari” and tactile “hari” each have their own approaches suitable to improving their properties.