There are two review papers worth reading on sea buckthorn if you are the kind of person who wants to know what is actually inside the fruit rather than what it might do. One is in RSC Advances (2020). The other is in Frontiers in Nutrition (2022). Between them, they catalogue nearly everything modern chromatography has been able to identify inside Hippophae rhamnoides. Read together, they explain — without asking the fruit to behave like a medicine — why the berry is amber, why it is oily in a way most fruits are not, and why it keeps.
Most fruits are mostly water and sugar. Sea buckthorn is unusual because it is water, sugar, oil, pigment, acid and antioxidant, in roughly the same berry. That density is the reason nutrition literature returns to it. Both reviews above open with the same observation — that the plant appears to have concentrated more compound families into a single fruit than almost any other temperate berry. What follows is a short guided tour of those families, taken directly from what the two reviews describe. Nothing about what the berry does in the human body. Only what the berry contains.
Family two — the carotenoids. The colour of the berry is not an accident. The reviews document that Hippophae rhamnoides carries an unusually high concentration of carotenoids — β-carotene, γ-carotene, lycopene, zeaxanthin and, characteristically, high amounts of zeaxanthin dipalmitate, a fatty-acid-esterified form of zeaxanthin found in very few plants (Frontiers in Nutrition 2022). It is the carotenoids, more than anything else, that give the fruit and its oils their amber, orange and deep-gold hues. In the reviewers' phrasing, the fruit is 'chromatographically painted' by its carotenoid load.
Family three — the tocopherols and tocotrienols. Both reviews note that sea buckthorn is one of the higher natural sources of vitamin E among fruits, carrying α-, β-, γ- and δ-tocopherols alongside all four tocotrienols (RSC Advances 2020). This is the fat-soluble antioxidant fraction. It is the reason both oils are, in food-technology terms, relatively stable — the tocopherols quietly protect the polyunsaturated fatty acids around them from oxidising too quickly. It is also part of the answer to why a cold-extracted sea buckthorn oil keeps a colour and character on the shelf that many other unstable oils lose.
Family five — vitamin C. The reviews cite a wide range for ascorbic-acid content — from around 400 mg to over 1,500 mg per 100 g of fresh berry, depending on cultivar, altitude, harvest season and processing (RSC Advances 2020). The higher end of that range is unusual among edible fruits. What both reviews are careful to note is that the vitamin C does not arrive alone — it arrives inside a matrix of flavonoids, minerals and organic acids, which food chemists studying its stability find behaves differently on the shelf and on the tongue than a synthetic ascorbate solution.
Family six — the phytosterols. β-sitosterol dominates, with smaller amounts of campesterol, stigmasterol and Δ5-avenasterol reported across studies (RSC Advances 2020). Phytosterols are the plant-kingdom equivalent of cholesterol — the structural sterols that sit inside the plant cell membrane. Both sea buckthorn oils carry them; the seed oil somewhat more than the pulp oil.
Family seven — the small everything-else. The reviews close their compound inventories with the categories that are rarely inventoried elsewhere: triterpenoids (ursolic acid, oleanolic acid), organic acids (malic, quinic, tartaric), amino acids (across the essential and non-essential ranges), a spectrum of macro- and trace minerals (potassium, calcium, magnesium, iron, manganese, zinc, selenium), and volatile aroma compounds that give the fruit its characteristic astringent-sweet nose (Frontiers in Nutrition 2022). The Frontiers review catalogues over 190 individual compounds across all these families combined — which is the number our own labels reference.
What is worth pausing on, at the end, is why the fruit contains so much. Both reviews return, at different points, to the same explanation. Hippophae rhamnoides is a plant that grows in some of the harshest environments in the temperate world — high altitude, poor soil, thin air, intense UV, brutal winters. Every family on this list is a plant response to that environment. The fatty acids stabilise its cell membranes in cold. The carotenoids and flavonoids protect it from UV. The tocopherols protect the fatty acids from oxidation. The vitamin C and phenolics defend it against pathogens. The phytosterols hold its cell walls together. The berry is not concentrated because it is trying to be a superfood. It is concentrated because it is trying to survive.