Moisture Absorption and Retention Abilities of the Water-Extracted Taheebo

Hiroshi SHIMOFURUYA*, Ikukatsu SUZUKI, Yoshihiko KUNIEDA, Yutaka TSUZIDE, Yoko TSUCHIE and Jiro SUZUKI††

Department of Materials Science & Engineering, Suzuka National College of Technology; Shiroko-cho, Suzuka-shi 510-0294 Japan
Department of Clinical Nutrition, Faculty of Health Science, Suzuka University of MedicalScience; Kishioka-cho, Suzuka-shi 510-0293 Japan
†† Department of Ecological Engineering, Toyohashi University of Technology; Hibarigaoka, tenpaku-cho, Toyohashi-shi 441-8580 Japan

Hygroscopic abilities of Taheebo, extracted from the bark of Tabebuia avellanedae Lorents and Griseb, were examined by physico-chemical technics in comparison with those of urea, glycerol and D-glucitol used in cosmetics. When the relative humidity increased from 31.0% to 91.0%, the increased amounts of the moisture absorption capacity of urea and D-glucitol after 24 hours standing were 133% and 98% respectively, whereas its amount of the water-extracted Taheebo was 66%. The moisture absorption capacity of urea and D-glucitol were dependent on changes in the relative humidity, while the moisture absorption capacity of water-extracted Taheebo was not greatly influenced by changes in the relative humidity. Furthermore, in the dry silica-gel desiccator, the water-extracted Taheebo showed the best moisture retention capacity among the samples tested. These results suggested that the water-extracted Taheebo was a desirable hygroscopic material because it exhibited relative high hygroscopic ability under conditions with various humidity and high moisture retention capacity even in the dry silica-gel desiccator.

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