A comparison of six solvents for the extraction of jojoba seed

Summary Data are presented which show the effects of different solvents on the yield and properties of liquid wax fromSimondsia chinensis (jojoba) and on the characteristics of the hydrogenated waxes obtained from the liquid waxes. Three reagent grade solvents, carbon tetrachloride, benzene, and isopropyl alcohol, and three commercial grade solvents, heptane, hexane, and tetrachloroethylene, were evaluated as extractants for the liquid wax from jojoba. Soxhlet-type of extractions were carried out under conditions in which the solvent was the only significant variable. Four of the solvents extracted essentially the same amount of material from the seed while isopropyl alcohol extracted significantly more material and tetrachloroethylene significantly less. Obviously the difficulties involved in separating the solids recovered from the isopropyl alcohol extraction preclude its use as the extracting solvent for jojoba wax. The density of the liquid waxes varies from 0.8631 to 0.8648; the waxes from the tetrachloroethylene and hexane extractions had the lowest value and the wax from isopropyl alcohol the highest. In each case, regardless of the solvent used, a precipitate developed in the liquid wax after it had been desolventized and stored for 7–10 days. Hydrogenation of clear fractions and precipitate containing fractions of these liquid waxes showed that the precipitate had no apparent effect upon the melting point or hardness of the resulting solid wax. Some of the liquid waxes required a longer hydrogenation time to attain an iodine value of about 1. At this iodine value all of the solid waxes had melting points between 66 and 68°C. Hardness values of all the solid waxes as measured by the Trionic hardness gauge were 90. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.