When turmeric stains a white shirt, it imparts a yellow-orange color. However, when the stained area is washed with soap or detergent, the color may appear to change to red. This phenomenon is due to the chemical properties of turmeric and how it interacts with soap.
Turmeric contains a group of pigments called curcuminoids, with the primary pigment being curcumin. Curcumin is responsible for the yellow-orange color of turmeric. It is a hydrophobic compound, meaning it is not water-soluble but dissolves well in fats and oils.
When you wash a turmeric stain with soap or detergent, it acts as a surfactant. Surfactants are molecules that have both hydrophilic (water-attracting) and hydrophobic (oil-attracting) parts. When soap comes into contact with the turmeric stain, it surrounds the hydrophobic curcumin molecules and helps lift them off the fabric's surface.
During this process, the curcumin molecules become dispersed in the soapy water, and their color can change due to the interaction with the surrounding environment. In an alkaline environment, such as that created by soap, curcumin undergoes a chemical transformation and can exhibit a different color. In this case, it may appear reddish or pinkish.
The change in color is not permanent and typically does not affect the white shirt once it is rinsed and washed thoroughly to remove the turmeric residue. It is essential to wash the stained area as soon as possible to prevent the turmeric from bonding more strongly with the fabric and making the stain harder to remove.
It's worth noting that turmeric can be a challenging stain to remove from clothing, especially on white fabrics. If you encounter a turmeric stain, treating it promptly with a stain remover or a mixture of vinegar and water before washing can improve the chances of successful stain removal.