Turmeric (Curcuma longa) is a plant native to south India and
Indonasia. It is also cultivated in China and the whole of South East
Asia. It is also called “Haldi”. Its tuberous rhizomes have been used as
a condiment, a colourant and an aromatic stimulant since antiquity.
Turmeric consists of various molecular constituents, including three
gold colour alkaloidal curcuminoid, curcumidesmethoxy curcumin
and bisdemethoxy curcumin. The curcuminoid content responsible
for colour, depends upon the turmeric variety and within a variety on
the maturity at harvest. It may be present to the extent of 4 to 8 %
in turmeric harvesting at the right maturity being an important factor
for colour and aroma. Some isomeric forms of curcumin are displayed
below (Figure 1):