Yellow curcumin refers to the natural compound curcumin, which is the principal curcuminoid found in turmeric, a spice derived from the roots of the Curcuma longa plant. Curcumin is responsible for the distinctive bright yellow color of turmeric. It is often used as a spice in cooking, particularly in Indian and Southeast Asian cuisine, and has a long history of use in Ayurvedic and traditional medicine due to its potential health benefits.