Publications by authors named "Emilie Yokoyama"

3 Publications

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A preliminary study to understand the effects of mask on tinted face cosmetics.

Skin Res Technol 2021 Mar 2. Epub 2021 Mar 2.

L'Oréal Research and Innovation, Tokyo, Japan.

Background: The recent COVID-19 pandemic has generalized the use of face mask in public area, and it is now common to wear it for long hours. But face mask interfere with cosmetics, and key concerns for tinted products are staining of the mask and degradation on face. Consumers have modified beauty routine by a decrease of makeup, but are now expecting new products adapted to face mask. Little is known about the mechanisms that affect most the makeup under the face mask, so that further studies are needed to develop adequate evaluation methods and products. In this study, the color transfer on mask and makeup degradation on face are assessed through a mixed approach of consumer and instrumental evaluation.

Materials And Methods: Two tinted face products (A and B) were applied by half face on 11 Japanese women, who conducted real-life activities with a face mask during 4 hours. Panelists evaluated the stain of their face mask by visual assessment, while the makeup degradation on face was evaluated by color measurement by instrumental method.

Results: No difference was observed between the two products for lasting on face, but consumer evaluation showed a better resistance of product A for color transfer on mask.

Conclusion: The mix of instrumental and consumer evaluation is a promising way to evaluate the makeup degradation on face and color transfer on mask, which are two key factors to develop mask resistant makeup products.
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http://dx.doi.org/10.1111/srt.13022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8014104PMC
March 2021

Japanese experiment of a complete and objective automatic grading system of facial signs from selfie pictures: Validation with dermatologists and characterization of changes due to age and sun exposures.

Skin Res Technol 2020 Dec 27. Epub 2020 Dec 27.

L'Oréal Research and Innovation, Clichy, France.

Objective: To evaluate the capacity of the automatic detection system to accurately grade, from smartphones' selfie pictures, the severity of ten facial signs in Japanese women and their changes due to age and sun exposures.

Methods: A three-step approach was conducted, based on self-taken selfie images. At first, to check on 310 Japanese women (18-69 years) enrolled in the northerner Hokkaido area (latitude 43.2°N), how, on ten facial signs, the A.I-based automatic grading system may correlate with dermatological assessments, taken as reference. Second, to assess and compare age changes in 310 Japanese and 112 Korean women. Third, as these Japanese panelists were recruited according to their usual behavior toward sun exposure, that is, non-sun-phobic (NSP, N = 114) and sun-phobic (SP, N = 196), and through their regular and early use of a photo-protective product, to characterize the facial photo-damages.

Results: (a) On the ten facial signs, detected automatically, nine were found significantly (P < .0001) highly correlated with the evaluations made by three Japanese dermatologists (Wrinkles: r = .75; Sagging: r = .80; Pigmentation: r = .75). (b) The automatic scores showed significant changes with age, by decade, of Wrinkles/Texture, Pigmentation, and Ptosis/Sagging (P < .05). (c) After 45 years, a significantly increased severity of Wrinkles/Texture and Pigmentation was observed in NSP vs. SP women (P < .05). A trend of an increased Ptosis/Sagging (P = .09) was observed.

Conclusion: This work illustrates, for the first time through investigations conducted at home, some impacts of aging and sun exposures on facial signs of Japanese women. Results significantly confirm the importance of sun avoidance coupled with photo-protective measures. In epidemiological studies, the AI-based system offers a fast, affordable, and confidential approach in detection and quantification of facial signs and their dependence with ages, environments and lifestyles.
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http://dx.doi.org/10.1111/srt.12982DOI Listing
December 2020

Determination of exposed sulfhydryl groups in heated beta-lactoglobulin A using IAEDANS and mass spectrometry.

J Agric Food Chem 2007 Aug 25;55(17):7107-13. Epub 2007 Jul 25.

Moorepark Food Research Centre, Teagasc, Fermoy, County Cork, Ireland.

This paper takes a new approach to determining which sulfhydryl groups are exposed during the heat denaturation of bovine beta-lactoglobulin A. The sulfhydryl groups exposed after heating were blocked with 5-((((2-iodoacetyl)amino)ethyl)amino)naphthalene-1-sulfonic acid (IAEDANS). The results show that IAEDANS is a suitable blocking agent, and its absorbance at 336 nm enabled the quantification of exposed sulfhydryl groups in a mixture of protein species by gel permeation chromatography. Combined with the specific fragmentation of bound IAEDANS by matrix-assisted laser desorption ionization (MALDI) MS/MS in negative ionization mode, this facilitated the identification of peptides that contained blocked cysteines after enzymatic digestion of the protein. During MALDI MS/MS of the peptides, in positive ionization mode, the IAEDANS molecule remained bound to the cysteines, making it possible to identify exactly which cysteine had been exposed after heating. In beta-lactoglobulin A it was found that cysteine 66 and cysteine 160 were predominantly exposed regardless of the length of exposure to heat.
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http://dx.doi.org/10.1021/jf070397rDOI Listing
August 2007