WATER-SOLUBLE MUCILAGE IN A MOISTURE MASK 19 times decreased from 12.05 min to 14.08 min with the increased concentration of mucilage used. This may be because film formation results from an aggregation of film-forming compounds, i.e., HEC, MC or mucilage, after the solvent evaporates (29). Therefore, film-formation time decreased with increasing concentration of film-forming agents. STORAGE STABILITY Results in Figure 5 show that the apparent viscosity of moisture masks containing 2% HEC + 5% humectant or 1% HEC + 1% mucilage was relatively stable within six weeks, and then decreased and leveled off at eight weeks. However, for moisture masks containing 2% MC + 5% humectant or 1% MC + 1% mucilage, the apparent viscosity started to decrease from the beginning, until the fourth or sixth week, and then leveled off. This may be attributed to different time courses of the coalescense of dispersed lipid droplets, and it resulted in the decreases in the apparent viscosity of moisture masks. The apparent viscosity of masks containing HEC was higher than that of those containing MC. The onset times of coalescense of dispersed lipids for those moisture masks con- taining HEC were later than for those containing MC. Therefore, the apparent viscosity of moisture masks containing MC decreased from the beginning of storage and then leveled off after six weeks. Although the apparent viscosity of moisture masks decreased during storage, no phase separation occurred. The moisture masks were stable for more than three months stored at 4øC. CONCLUSION Increasing concentration of water-soluble mucilage in moisture masks increased their water-holding capacity but decreased film-formation time. Moisture masks containing 1% water-soluble mucilage and 1% HEC have a higher water-holding capacity, al- though the apparent viscosity was lower than for those containing 2% MC and 5% humectant. ACKNOWLEDGEMENTS The authors express their gratitude to the National Science Council, Republic of China (Project No. NSC 88-2313-B-019-022) for its financial support. REFERENCES (1) S. Maeshige, Chemical studies on the green alga Monostroma nitidium Wittrock-I components sugar of the mucilage, Bull. Jap. Soc. Sci. Fish, 28, 326-334 (1962). (2) T. Kawabe, T. Nagaoka, G. Nagahama, H. Morita, and A. Ohbayashi, Generation of dimethyl sulfide from dimethyl-[3-propiothetin in an extract of green alga Monostroma nitidium and its retention by cyclodextrin, Agric. Biol. Chem., 53, 2587-2591 (1989). (3) S. Maeshige, Chemical studies on the green alga Monostroma nitidium Wittrock-II low molecular carbohydrate in the alga, Bull. Jap. Soc. Sd. Fish, 28, 606-609 (1962). (4) T.C. Lii, Physico-chemical properties of water-soluble polysaccharides of Monostroma nitidium. MS thesis, National Taiwan Ocean University (in Chinese) (1986).

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