Antimicrobial activity of 235 natural flavor and fragrance materials was investigated using 4 bacteria and 2 fungi. Antimicrobial activity against bacteria and yeast was defined as percent inhibition of viable cell count after incubation with sample in phosphate buffer for 10min. Antimicrobial activity against mold was defined as percent inhibition of colony area on agar plate containing sample. Two hundred and three samples were very effective against at least one of the six test microorganisms. Samples consisting of chain terpene alcohols, cyclic carbonyl compounds, cyclic ethers and phenolic compounds as major components were very effective against S. aureus and/or P. aeruginosa. Minimum inhibitory concentration (MIC) was determined by agar dilution method. Samples which showed 100% of antimicrobial activity against B. subtilis, E. coli, P. aeruginosa and A. niger at 1000ppm gave a MIC of 2000ppm or over. Antimicrobial activities of samples were compared with that of p-hydroxybenzoic acid esters. Forty-eight samples were more effective than methyl p-hydroxybenzoate. The degree of antimicrobial activities of eight samples followed the same order as that of n-propyl p-hydroxybenzoate and n-butyl p-hydroxybenzoate.

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Characteristic behavior of human skin fibroblasts in collagen gels has been investigated in order to clarify the interactions among the cells, collagen matrix, and diffusible factors. Dynamic behavior of fibroblasts in collagen gels was analyzed by video microscopy. Features that were observed include the development of extremely elongated cell shape and interactions between the cells and collagen fibrils. The interactions eventually resulted in the contraction of collagen gels. The contraction can be expressed in a quantitative way by size of the gel. It was stronger with human skin fibroblasts than with 3T3 established cells or with human fibrosarcoma cells. The intensity and rapidity of contraction increased with concentration of fetal bovine serum. Human skin fibroblasts in the contracted collagen gels stopped multiplying when density of collagen fibrils reached at more than 100μg/mm³. Fibroblasts under this condition had a smaller activity of protein synthesis than those in confluent monolayer culture. Growth response of fibroblasts in the contracted gels to epidermal growth factor was considerably retarded. These results suggest that human skin fibroblasts in collagen gels was in a resting state and in an environment more similar to in vivo tissue as compared to cells in conventional monolayer culture. The dynamic dehavior of fibroblasts in collagen gels, the ability of fibroblasts to contract the collagen gels, and the cellular activity in contracted collagen gels might be new indices for evaluation of regulatory materials on cellular activity in the skin.

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To develop a novel makeup which is effective in making wrinkles less visible, optical properties of the makeup compornents and their mixtures were systematically studied.
It was discovered that within a specific composition range, it was possible to produce a makeup more effective in making wrinkles much less visible than possible with other mixtures. The composition of this “SOFT FOCUS MIXTURE” was found to be strongly dependent on the optical properties as well as the ratio of the powder to the oil. Two major factors found to contribute to the reduction of wrinkle visibility are: (a) Optical blurring of the outlines of wrinkles, and (b) Reduction in the differerence of lightnesses due to diffuse reflection. The first is strongly dependent on the concentration of the oil phase while the second is affected by the gloss of the powder. By optimizing these two factors, effective makeup have been prepared to make wrinkles less apparent.

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As an attempt to globally evaluate the degree of hair damage, a study was carried out on a tensile strength test method of human hair. In order to minimize the variation of measured value, the gauge Iength of sample was shortened to 1mm by fixing both sides of it with tape. Even the same one hair has a different cross-sectional area and shape at each site of it, and microscopic damage may be present on it locally. By shortening the gauge length, measurement of cross-sectional area becomes more accurate and microscopic check of the sample also becomes easy. We named this method ‘the multi-point tension test method’, in which tensile strength could be measured at some points from the root to the tip of each hair. Thereby the degree of time-course damages by the accumulation of daily little damage could be appeared. From the result, Japanese normal hair could be ranked into five levels from the standpoint of hair strength.
By this method, the effects of some cosmetics containing collagen or keratin derivatives could be recognized. And the correlations between hair strength and some metals in hair, which move from and/or into the hair easily in various water solution, could be appeared.
Besides, the method for the confirmation of sorption of keratin peptide into hair was investigated. This technique, consisting of a circulation-system of keratin peptide into a hair-packed column and the quantification of sorption into the hair from liquid phase, was useful and speedy for the study of characteristics of keratin peptide.

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In considering the effect of cosmetics, the moisturizing effect on the skin is most important.
This consists of two components, one being the occlusivity which suppress water evaporation, and the other is water holding capacity. A new method for measuring the water evaporation rate (WER) has been developed by us. The present study was carried out in order to clarify the following: 1) The relationship between WER through the skin and skin condition. 2) The factors which determine occlusivity. In conclusion, it was recognized that the morphology of the skin surface become fine with decreasing WER and it was clarified that occlusivity could be explained in terms of lnorganic organic balance (10B), visvosity and water holding capacity.

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The sorption of keratin hydrolysate, as an inter-molecular cystine rich polypepetide, to hair and the cosmetic effect have been studied.
The amount of keratin hydrolysate sorbed to hair was determined by a novel method: the determination of the amount of sulfhydryl residues (R-SH) in keratin hydrolysate produced by the chemical interaction between cysteine residues (R-SH) in hair being reduced and cystine residues (R-S-S-R) in keratin hydrolysate. A large amount of R-SH was produced in keratin hydrolysate when reduced hair was immersed in the medium of the buffer solutions containing keratin hydrolysate, whease only a trace amount of R-SH in the control buffer was found when keratin hydrolysate was not present. The chemical alternation of hair was examined by the fluorescent microscopic observation of R-SH after labelled with N-(7-dimethylamino-4-methyl-coumarinyl)-maleimide (DACM). Intensive fluorescence was observed on the reduced hair, whease reduction of fluorescent intensity was observed on the keratin hydrolysate treated hair. The result showed a decrease of R-SH in the reduced hair. The decrease of cystine residues of the permed hair was also found by amino acid analysis, when the hair was treated with keratin hydrolysate after reduction in the permanent waving process. As the cosmetic application of keratin hydrolysate, the effect of keratin hydrolysate on the bleached and permed hair was demonstrated in the process of permanent waving as the waving efficiency.
These results implies that the sorption of cystine-rich keratin hydrolysate to the reduced hair was due to SH/SS interchange reaction between the hair and the keratin hydrolysate. It was also suggested that the effectiveness of keratin hydrolysate on the waving efficiency was based on the increase of hair elasticity due to the newly formed covalent bonds between the hair and the keratin hydrolysate.

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The luster of human hair was studied in relation to the physical properties of hair surface. The luster was evaluated by means of Rod Method (visual evaluation) and Goniophotometry (instrumental evaluation). From the relationship between both methods, it was found that it may be possible to evaluate the luster of human hair by S value as a parameter.
In order to clarify the factors which influence the luster of human hair, the physical properties of lusterous hair were compared with those of non-lustrous hair. The factors discussed here were as follows: (1) refraction index of hair surface, (2) Number and width of hair cuticles, (3) Number of cuticle cell layers. The physical properties, from root end to tip, of human hair were also investigated in relation to the luster.
In addition, the effects of cosmetic treatments such as cold waving, brushing and blowing with heat were examined. Brushing and cold waving were found to have a great effect on the decrease of the luster.

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