SENSORY CHARACTERIZATION OF COSMETIC EMULSIONS 93 Figure 2. MFA of consumers’ answers to the CATA survey. (A) Representation of terms of the CATA survey. Colors indicate contribution of factors to the dimensions. Terms in black had the highest contribution (CTR 8), terms in medium gray had medium contribution (CTR 3–8), and terms in light gray had the lowest contribution (CTR 3). (B) Representation of emulsion samples. Ellipses indicate the result of hierarchical cluster analysis.

JOURNAL OF COSMETIC SCIENCE 94 oily/greasy, hard to spread, gluey, and dull in their appearance. The relationship between these terms is coherent considering that a light cream is expected to be easy to apply, whereas a heavy cream could be regarded as oily/greasy. Having these terms in this distri- bution suggests that consumers were able to distinguish between the emulsions based on their sensory properties. Looking at the second dimension, the terms “off-white,” “wet/ not fully dry,” “glossy/shiny (afterfeel),” and “cooling” had a correlation of 0.7 or higher, whereas “bright white,” “white,” “dull,” “smooth/soft,” and “silky/smooth” had a correlation of -0.6 or lower. The results from MFA suggest that the fi rst dimension primarily discriminated emul- sions based on rub-out and pick-up characteristics, including how thick or thin they felt on spreading on the skin (i.e., sensation of thickness/viscosity). Appearance attributes, including glossiness/dullness and thickness also determined this axis. The second dimension was primarily related to the appearance of the emulsions, including color and glossiness/ dullness, as well as afterfeel after 3 min, including smooth and watery feeling, provided by the emulsions. An intriguing fi nding was that the terms “warming” and “cooling” did not appear to be antonyms in this study. Warming, located at the positive values of both dimensions, was in the cluster characterizing heavy creams. Cooling, located at the negative values of the fi rst dimension and positive values of the second dimension, was mainly used by consum- ers to characterize thin, glossy, off-white creams. As mentioned previously, “warming” was one of the least mentioned terms. It suggests that most consumers could not relate this term to any of the emulsions. Products can be designed to provide a warming sensa- tion on the skin on application (30) however, none of the emulsions in this study were designed to have a warming sensation on the skin. This can explain the infrequent use of the term. Characteristics that none of the emulsions will likely have (“warming” in this case) may cause negligible noise in the data because some consumers may still select these terms as a sensory attribute for certain samples. However, the low incidence of such cases did not affect signifi cantly the robustness and reliability of the results obtained. When looking at the frequency of mention of the term “cooling,” it can be seen that cooling was used very frequently. Typically, W/O emulsions (often called cold creams) are known to be cooling, providing a cooling sensation as water evaporates from the skin after apply- ing the product. However, “cooling” was selected a similar number of times for all emul- sions. This suggests that consumers could not really distinguish products based on this characteristic. Figure 2B shows the representation of emulsions in the MFA dimensions. This fi gure suggests that consumers were able to categorize the emulsions into groups. The principal axis was highly correlated with variables that belong to two separate groups. It opposed Emulsions 1 and 2 from Emulsions 3–6. From the perspective of appearance, Emulsions 1 and 2 were characterized as dull, whereas Emulsions 3–6 were characterized as shiny. From the perspective of skin feel during application, Emulsions 1 and 2 were considered heavy and the rest of the emulsions as light. The off-white trait of an emulsion practically coincides with the main factor. The second dimension sorted the samples based on color and afterfeel into two groups, one including Emulsions 2, 5, and 6 and the other includ- ing Emulsions 1, 3, and 4. Considering the color, a sharp discrimination was detected in the shade of the emul- sions (i.e., bright white or off-white). As shown in Figure 2B, Emulsion 1 was located