| 摘要 |
PROBLEM TO BE SOLVED: To provide a effervescent system having improved stability greatly as possible, concerning the generation of carbon dioxide and decomposition of acetylsalicylic acid as compared with a conventional method. SOLUTION: This effervescent system contains granules of a kind of solid organic food acid and at least one kind of bicarbonate salt of an alkali metal, and the surface of particles the of alkali bicarbonate is changed into at least 1wt.%, preferably 2 or 4wt.%, maximum 10wt.%. preferably <=8wt.% of dried alkali carbonate free from water of crystallization. The acid particle, preferably particles of citric acid, themselves may be coated by a reaction of a kind of carbonate and/or a bicarbonate in the conventional method. To obtain the prescribed change, a commercial alkali bicarbonate particle is heat treated at >=60 deg.C under <=40mbar, preferably <=20mbar in a vacuum container, after passing on the prefixed time for the required thickness of the layer, cooled to the temperature at <=60 deg.C while keeping the vacuum. |
