Pongamia pinnata locally known as Karanja is a medium sized evergreen tree planted for shade and as ornamental tree in the greater part of the country. It is a drought resistant salt tolerant, nitrogen fixing leguminous tree and to some extent tolerant to slight frost. The seeds are largely exploited for extraction of a non-edible oil, commercially known as “Karanja Oil” well recognized for its medicinal properties and also used in the manufacture of soap. Leaves are used as fodder and green manure. The wood of this tree is used as fuel throughout the country and also used for construction, tool handles and agricultural implements.
Pongamia pinnata is a drought resistant, nitrogen-fixing leguminous tree. It is also salt tolerant and to some extent tolerant to slight frost. It is a good shade tree. The shade provided by this tree is said to have cooling effect and is good for health.
The seeds are largely exploited for extraction of a non-edible oil, commercially know as “Karanja oil”, which is well recognized for its medicinal properties. The yield of fruit varies from 9 to 90 kg per free for different age trees. There is no systematic and organized collection of seeds. Mature seeds consist of 95% kernel and are reported to contain about 27.0% oil. The yield of oil is reported to be about 24.0 to 26.5% if mechanical expellers are used for the recovery of oil from the kernels, but it is only 18 to 22% from village crushers. The estimated potential of the seeds is about 1.11 lakh tons per year and that of oil is about 0.29 lakh tons and the oil produced is about 0.08 lakh tons.
- The crude oil is yellow orange to brown in colour which deepens on standing. It has a bitter taste and disagreeable odour rendering the oil non-edible.
- The oil is of great value in indigenous medicine as a stimulant and for the treatment of skin diseases; it has antiseptic, antiparasitic and cleansing properties.
- It is used in medicinal preparations for scabies and leucoderma. The furanoflavones present in karanja oil are helpful in enhancing pigmentation of affected skin. Undistilled oil is used in the manufacture of laundry soap and the distilled oil is used in the manufacture of toilet soap.
- The sulphonated oil is used in leather industry. Karanja oil is also used in manufacture of phenyles, greases, lubricants, massage oils and/edpoxy compounds. Villagers use this oil for burning lamps.
- The oil is also reported to have insecticidal properties. The cake is a good fertilizer and has good soil binding property. It also helps to some extent in controlling soil insects and nermatodes.