OITICICA OIL

Oiticica oil is obtained from the nuts of the tropical tree, Licania rigida, which is indigenous to the interior regions of Northern Brazil. L. arborea in Mexico and Central America and L. crassifolia in Surinam have been the source of similar oils. Limited attempts to cultivate the oil-producing trees in the United States and England have been unsuccessful.
The freshly expressed oil is a yellowish viscous liquid, which gradually solidifies within a few days to a pale green solid with the consistency of lard. Heating for 30-60 min at 210-220°C renders the oil permanently liquid. Brazilian natives originally recovered the oil by boiling crushed nuts and decanting the floating oil. This inefficient method was replaced by the use of continuous screw or hydraulic presses to express the oil. Some mills recovered the residual oil from the presscake by extracting with petroleum ether or trichloroethylene.
Oiticica oil resembles tung oil in having much of its composition in the form of fatty acids with conjugated double bonds. The major source of this conjugated system in oiticica oil is licanic acid [CH3(CH2)3CH = CHCH = CH-CH = CH(CH2)4CO(CH2)2COOH]. It has the distinction of being the first ketonic unsaturated fatty acid detected in natural products. According to early reports licanic acid was said to represent about 75% of the oil. However, further studies allowing improved analyses suggest that these estimates were too high. It has been shown that licanic acid constitutes 42% of the total fatty acid content of oiticica oil; oleic plus linoleic acids, 23%; eleostearic acid, 14%; stearic acid, 12%; palmitic acid, 7%; and an unidentified unsaturated hydroxy acid, 2%. Thus, unsaturated fatty acids comprised about 80% of the oil.
Although oiticica oil was used extensively by the coatings industry when tung oil was unavailable or expensive, currently all drying oils have difficulty competing with synthetic compositions such as vinyl, acrylic, epoxy, and urethane resins. Because oiticica oil no longer enjoys an economic advantage over tung oil, its use in the paint and varnish industry also appears limited.