The Curry leaves are a fair source of vitamin A and they are also a rich source of calcium, but due to presence of oxalic acid in high concentration, its nutritional availability is affected. More over the presence of oxalates may also cause kidney stones. The botanical name of Curry is Murraya koenigii (Linn.) Sprengel and belongs to the family of Rutaceae.
Curry leaves are extensively grown and used in Southern India for the authentic flavor, but are also of some significance in northern India. Together with South Indian people, curry leaves are exported in different parts of the globe. Curry powder made after grinding curry leaves, is a British invention to imitate the flavor of Indian cooking with minimal effort. In Indian cuisine curry leaves are used in its fresh and raw form for some recipes, they are fried in butter or oil for a short while. Since South Indian cuisine is dominantly vegetarian, curry leaves rarely appear in non-vegetarian food. The leaves have soft surface but are usually removed before serving, however if eaten they are harmless. Vacuum self-drying of curry leaves gives a better product of greenish color than those dried by other methods.
The free amino acids present in the curry leaves are asparagines, serine, aspartic acid, glutamic acid, threonine, proline, alanine, tyrosine, tryptophan, histidine etc. The leaves also contain a crystalline glucoside, koenigin and a resin. Twigs and leaves of Curry contain 0.8 % potash on dry matter basis. Fresh leaves, on steam distillation under pressure yield 2.6 % of a volatile oil, which may find use as a fixative for heavy type of soap perfume; distillation at ordinary pressure gives very poor yield of oil, while distillation with superheated steam yields dark colored foul-smelling oil. Rectified curry leaf oil is deep yellow in color with a strong spicy odor and pungent clove like taste.
The leaves of Curry plant have been used for centuries mostly in South India and to the lesser extent in rest of India as a natural flavoring agent in various curries and chutneys. Besides fresh leaves dried leaves and powdered leaves are also used. The use of essential oil as flavor or perfume is not yet popularised. There is a good scope to create demand considering its virtues. In fact, the oil also has medicinal virtues also. The leaves, bark and the root of the Curry plant are used in indigenous medicine as a tonic, stomachic, stimulant and carminative. The Curry leaves taken with pepper early in the morning in empty stomach reduce blood sugar. An infusion of the roasted leaves is used to stop vomiting. The dry leaves of Curry are ingredient for many herbal medicines. The juice of the root is taken to relieve pain associated with kidney.
The wood is grayish white, hard, even, close grained and durable. It can be used as timber for manufacture of many types of products. The Curry plant therefore is a multi-product source. If it can be utilised in a planned manner a chain of rural industrial units can be planned and implemented.
