Turmeric is yellow in acid and neutral substances, but turns bright red with bases.

Turmeric as a Natural Indicator

Turmeric, a commonly used spice in cooking, contains a pigment called curcumin. Curcumin is responsible for the vibrant yellow color of turmeric. This pigment has the ability to change its color when exposed to different pH levels, making turmeric a natural indicator.

Color Change in Acid
When turmeric is added to an acidic solution, such as lemon juice or vinegar, it changes its color to a reddish-brown or orange-yellow. This is due to the acid causing a structural change in the curcumin molecule, altering its absorption and reflection of light. The change in color is a result of the acidic environment breaking down the curcumin molecule into smaller components.

Color Change in Base
On the other hand, when turmeric is added to a basic solution, like baking soda or soap, it turns into a bright yellow or yellowish-brown color. This is because the basic solution causes the curcumin molecule to become more stable, resulting in a different absorption and reflection of light. The change in color is a consequence of the basic environment modifying the structure of the curcumin molecule.

Turmeric as a pH Indicator
The color change of turmeric in response to different pH levels makes it a useful pH indicator. pH indicators are substances that exhibit different colors depending on the pH of the solution they are added to. Turmeric can be used as a natural pH indicator in various applications, such as in chemistry experiments or in the kitchen to determine the acidity or alkalinity of a food or beverage.

Conclusion
In conclusion, turmeric changes its color when added to an acid or base. It turns reddish-brown or orange-yellow in an acidic solution and becomes bright yellow or yellowish-brown in a basic solution. This color change is attributed to the alteration of the curcumin molecule's structure and its absorption and reflection of light. Turmeric's ability to act as a natural pH indicator makes it a valuable tool in various scientific and culinary settings.

Turmeric turns yellow colour in presence of acid
turmeric turns red colour in presence of base