Indicator[edit]
Turmeric paper, also called curcuma paper or (in German literature) "Curcumapapier" is paper steeped in a tincture of turmeric and allowed to dry. It is used in chemical analysis as an indicator for acidity and alkalinity.[25] The paper is yellow in acidic and neutral solutions and turns brown to reddish-brown in alkaline solutions, with transition between pH of 7.4 and 9.2.[26]
For pH detection, turmeric paper has been replaced in common use by litmus paper. Turmeric can be used as a substitute for phenolphthalein, as its color change pH range is similar.