Hempseed Oil—Influence of the Genotype on the Composition in a Two-Year Study

Abstract Seeds of 51 different hemp genotypes, 25 hemp varieties, 19 hemp accessions as well as 7 hemp samples from a cross-breeding program of a Hungarian Institute (GATE), grown in 2000 and 2001 were investigated regarding the oil content as well as fatty acid and tocopherol composition. The oil content ranged between 26.3 in 2001 and 37.5 g/ 100 g in 2000 with 33.2 g/100 g as mean amount in 2000 and 31.2 g/100 g in 2001. The oil contained high amounts of unsaturated fatty acids like linoleic and α-linolenic acid, which comprised about 80% of the total fatty acids. Hemp seed oil also consisted of remarkable amounts of γ-linolenic and stearidonic acid. The concentrations varied from 0.67 to 4.08 g/100 g and 0.39 to 1.60 g/100 g, respectively, in dependence of the genotype. The content of γ-linolenic and stearidonic acid were both highly correlated (r = 0.87), while γ-tocopherol was not correlated to the total sum of polyunsaturated fatty acid. Tocopherols mainly consisted of γ-tocopherol (36 to 97 mg/100 g). This made up to about 85% of the total tocopherols. In the oil also small amounts of α-tocopherol were found (2 to 10 mg/100 g). The effect of the year of cultivation on the composition of the oil was less pronounced than the influence of the genotype. Therefore the seed material, presented in this paper shows interesting possibilities to improve the composition of hemp seed oil.