Oil content in seeds of sea buckthorn is on average 7-11 % while oil content of the fruit pulp is around 1.5-3 %. Seed oil is characterized by high contents of polyunsaturated fatty acids while pulp oil contains monounsaturated fatty acids and carotenoids. Both oils also contain dense amounts of tocopherols, tocotrienols and plant sterols.
Fatty acids
Oils from sea buckthorn seeds and pulp differ considerably in fatty acid composition. While linoleic acid and α-linolenic acid are the major fatty acids in seed oil, sea buckthorn pulp oil contains approximately 65% combined of the monounsaturated fatty acid, palmitoleic acid, and the saturated fatty acid, palmitic acid. This results in a major difference between the sea buckthorn oil extracted from seeds and the sea buckthorn oil extracted from the fleshy part of the fruit, in term of appearance and consistency. Sea buckthorn fruit oil is dark orange in color and has a thick consistency, whereas the seed oil is pale yellow and does not solidify under refrigeration. Few other vegetable oils contain a similar quantity of these fatty acids. The high proportion of unsaturated fatty acids are also responsible for the relatively poor shelf life, as they cause sea buckthorn oil to turn rancid quickly.
Tocopherols and tocotrienols
is the major vitamin E compound in sea buckthorn. Seed oil also contains considerable amounts of gamma-tocopherol. The total amount of tocopherols and tocotrienols is roughly 64–300 mg/100 g in seed oil and 100–481 mg/100 g in pulp oil.
Carotenoids
As carotenoids are the pigments that give sea buckthorn berry its distinctive orange-red color, these compounds are present in considerable amounts both in pulp oil and in seed oil; the average carotenoid content of pulp oil is 350 mg per 100 grams, as compared to 67.5 mg per 100 grams in seed oil. The total content of carotenoids in pulp oil varies greatly between different growth locations and subspecies, and between components, where total carotenoids were up to 85 mg/100 g in seed oil, and up to 1000 mg/100 g in pulp oil. In general, the main carotenoids present in pulp oil are beta-carotene, zeaxanthin and lycopene.
Plant sterols
Both seed and pulp oil also contain considerable amounts of plant sterols. Beta-sitosterol is the major sterol compound throughout the berry which constitutes 57-83% of total sterols.
Preliminary research on sea buckthorn oil has been conducted for its potential biological properties, but there is no high-quality evidence as of 2018 that it has any confirmed benefits. Sea buckthorn oil is under preliminary research for its possible effects on blood pressure, cholesterol, and blood triglycerides, and for its use by oral intake to improve antioxidant status by increasing blood levels of beta-carotene and vitamin E.