JOURNAL OF COSMETIC SCIENCE 512 Figure 3. Elasticity values for F-YOP (treatment) and control product in the cheek. The value decreased in the control region, and was maintained at pretreatment levels in the treatment region. before treatment after treatment. six months or more. If the ratios of yoghurt to pack base are 5:5 (1:1), it has a putrid smell of yoghurt. We tested several ratios of yoghurt to pack base (1:9, 2:8, and 4:6). All were stable and did not have a putrid smell of yoghurt. In consideration of the feel upon ap- plication and unit cost, we determined that 4:6 should be the fi nal ratio. O. humifusa powder was mixed with YP immediately prior to use for freshness, and the optimal powder ratio was determined as 3% of the total volume. This powder tends to gel when combined with water, and so if the amount of powder is increased, it will affect the application feel and washing. The moisture value was superior with F-YOP treatment compared to the control product that was used as the control. The TEWL decreased after treatment and the values were superior compared to the control. Elasticity decreased in the control region however it did not change in the F-YOP-treated region. Thus, F-YOP treatment supplied effi cient moisture to the skin and helped maintain elasticity. Figure 4. Melanin values for F-YOP (treatment) and control product. There was no effect on melanin in either group. The melanin value decreased in the treated forehead region, in comparison to the control. forehead-before forehead-after cheek-before cheek-after chin-before chin-after.

EFFICACY OF F-YOP FACIAL MASKS 513 Figure 5. Erythema values for F-YOP (treatment) and control product. The erythema value decreased in the treatment region of the cheek, compared to the control. forehead-before forehead-after cheek-before cheek-after chin-before chin-after. For this reason, physiological materials may act as an evaluation factor. Fermented milk at 1% fi nal concentration was comparatively more dominant than the positive control in DPPH and lipoxygenase assays. In theory, if fermented milk is added to sterile milk by 10 w/w%, this activity improves. We did not confi rm this with a long-term in vivo practical test, but in this study, we found that the elasticity value decreased in the control region but increased in the treatment region. We believe that this product will be suitable for dry-skin patients because of the associated reduction in TEWL, increased moisture, and lack of preservatives. There is an increasing demand for the cosmetics industry to produce products that are safe, effective, stable, and provide user convenience (19). Skin products that are made from natural materials are less likely to cause irritation in consumers with sensitive skin because there are no preservatives or additives. We studied the stability of our F-YOP product for over six months, and we did not fi nd any changes in the deposits, color, or fl avor. Our product appears to be effective at improving skin moisture and brightness, and in reducing TEWL. ACKNOWLEDGMENTS This work was supported by a Korea Science and Engineering Foundation (KOSEF) grant funded by the Korean government (MEST) (No 2009-0063466) REFERENCES (1) M. Turkoglu and N. Cigirgil, Evaluation of black tea gel and its protection potential against UV, Int. J. Cosmet. Sci., 29, 437–442 (2007). (2) M. Masuda, K. Murata, A. Fukuhama, S. Naruto, T. Fujita, A. Uwaya, F. Isami, and H. Matsuda, In- hibitory effects of constituents of Morinda citrifolia seeds on elastase and tyrosinase, Nat. Med. (Tokyo), 63, 267–273 (2009).