Karanji, commonly called as Pongam oil tree, is native to tropical south east Asian countries including India, Srilanka, China, Japan. Tree normally grows in humid and sub-tropical environments, but well-suited to penetrating heat levels, withstanding up to 50° C. The tree is very tolerant to saline conditions and alkalinity. Like neem tree, each part of karanji is used to serve different purposes.
Karanji seeds contains 30 – 40% oil in them. Oil is extracted from the seeds through expeller pressing, solvent extraction techniques. Oil extracted varies from yellowish-orange to brown colour. It is toxic with obnoxious odour and taste, hence deemed as non-edible oil. The main constituents of karanji oil are karanjin, tannin and karanjachromene.
Karanji de-oil cake:
Toxic flavonoids in karanji oil cake are oil soluble compounds. Karanji oil cake undergo solvent extraction process, where it is treated with hexane, to remove the toxic ingredients. Outcome of this process is karanji de-oil cake. De-oil cake is used as fertilizers. De-oil cakes has 1-3% oil in it.
Karanji oil cake:
Karanji oil cake, seed residue after oil extraction is high in protein content. But the toxic flavonoids like karanjin, tannin and pongamol alkaloids remain in the cake. The nitrification inhibitory properties of these flavonoids and the amount of nitrogen (4%), phosphorous (1.1%) and potassium (1.3%) makes it an effective pesticide. It blends well with other fertilizers and helps in controlling nematodes and improving soil fertility.
- Karanjin Content: min 20,000 ppm
- Specific Gravity: 0.925 – 0.940
- Refractive Index: 1.4734 – 1.4790
- Acid Value: 20
- Saponification Value: 186 – 196
- Iodine Value: 80 – 90
- Unsaponificable Matter: 3.0
- Organic Matter: 80 – 90%
9. Fatty acid composition in %
- Palmitic Acid: 3.7 – 7.9
- Stearic Acid: 2.4 – 8.9
- Arachidic Acid: 2.2 – 4.7
- Behanic Acid: 4.2 – 5.3
- Lignoceric Acid: 1.1 – 3.5
- Oleic Acid: 44.5 – 71.3
- Linoleic Acid: 10.8 – 18.3
- Eicosenoic Acid: 9.5 – 12.4
Phosphorous 205: 0.9%
Potassium 20: 1.3%
Oil Content: 5%
Uses of Karanji oil:
- It acts as a lubricant for machines.
- It is one of the preferred water-paint binder in painting industry
- A natural fertilizer and pesticide in agriculture
- Used in biodiesel production.
- Key ingredient in washing soap making and tanning industries.
- Helps to cure skin ailments, rheumatism, pigment enhancement.