Turmeric

Turmeric is a South Asian relative of ginger, so its not surprising that fresh turmeric resembles a yellow-orange ginger rhizome.  In North America, turmeric is generally used dried, but when fresh it can be sliced and used in curries.

The bright colour of turmeric is due to the compound curcumin, which is commerically extracted and used as a food colouring.  Along with being an excellent dye, curcumin is a strong antioxidant which can help prevent food spoilage.  As an ingredient, turmeric is what gives blends of curry powder their yellow colour, and in cheaper mixtures is used as a filler.  Turmeric contributes a woody, earthy aroma to dishes, but little flavour other than a slight bitterness and heat