Analytical characterization of hemp (Cannabis sativa) seed oil from different agro-ecological zones of Pakistan

Cold-pressed oil content of Cannabis sativa (hemp) seeds from three different agro-ecological zones of Pakistan ranged from 26.90 to 31.50%. Protein, fiber, ash, and moisture content were found to be 23.00-26.50, 17.00-20.52, 5.00-7.60, and 5.60-8.50%, respectively. Results of some other physical and chemical parameters of the oil were as follows: iodine value, 154.00-165.00; refractive index (40 degrees C), 1.4698-1.4750; density (24 degrees C), 0.9180-0.9270 mg mL(-1); saponification value, 184.00-190.00; unsaponifiable matter, 0.70-1.25%; and color (1-in. cell), 0.50-0.80 R + 27.00-32.00 Y. The induction period (Rancimat, 20 L h(-1), 120 degrees C) of the nondegummed and degummed oils ranged from 1.35 to 1.72 h and from 1.20 to 1.49 h, respectively. Specific extinctions at 232 and 270 nm were 3.50-4.18 and 0.95-1.43, respectively. The hemp oils investigated were found to contain high levels of linoleic acid, 56.50-60.50%, followed by a-linolenic, oleic, palmitic, stearic, and gamma-linolenic acids: 16.85-20.00, 10.17-14.03, 5.75-8.27, 2.19-2.79, and 0.63-1.65%, respectively. Tocopherols (alpha, gamma, and delta) in the nondegummed oils were found to be 54.02-60.40, 600.00-745.00, 35.00-45.60, respectively, and were reduced to 29.90-50.00, 590.00-640.00, and 30.40-39.50 mg kg(-1), respectively, after degumming. The results of the present analytical study, compared with those found in the typical literature on hempseed oils, showed C. sativa indigenous to Pakistan to be a potentially valuable nonconventional oilseed crop of comparable quality.