| 摘要 |
PURPOSE:To obtain annatto dyestuff having excellent acid resistance and suitable as a coloring matter for foods, by dissolving annatto dyestuff in an alkaline water and/or an aq. alcoholic soln., homogeneously adding a fatty acid thereto, and neutralizing the resulting dispersion. CONSTITUTION:One pts.vol. annatto dyestuff such as bixin or norbixin is dissolved in not less than 20pts.vol. aq. alkaline soln. of a monohydric alcohol. 5- 100wt% (based on the amount of the annatto dyestuff) fatty acid such as stearic acid or palmitic acid is slowly added to the resulting soln. to homogeneously disperse it in the acid. An acid such as hydrochloric acid or tartaric acid is added thereto to neutralize the resulting dispersion to a pH of 6-7, whereby acid resistance can imparted to the annatto dyestuff. Even when the resulting annatto dyestuff is added to a strongly acidic soln. such as acidic sugar solution, homogeneous state can be kept over a long period of time, and neither precipitation nor ring formation occurs. |
