Phytosterols in Sea Buckthorn: Beta-Sitosterol and What the Berry Carries

By Dr. Raj Dhadwal

Most people meet sea buckthorn, also spelled seabuckthorn, through vitamin C or through omega 7. Phytosterols are the part of the berry nobody puts on a label, and they sit in the two oil fractions rather than in the watery part of the fruit. If you searched the word because you saw it on an ingredient panel or in a composition paper, this is what the published literature actually reports about where these compounds are, which ones dominate, and how much of them survives the way a berry is processed.

Phytosterols are plant sterols that live in the fat of the berry, not the juice. Beta-sitosterol is the dominant one in sea buckthorn, and published figures put seed oil at roughly 3 to 15 times the sterol concentration of pulp oil, depending on cultivar and method.

What follows is composition: where the sterols sit, which ones dominate, and what processing does to them.

What are phytosterols?

Sterols are a structural class. Every one of them shares a four-ring carbon skeleton with a hydroxyl group on one end and a side chain on the other. Plants build a family of closely related molecules on that skeleton, and those are the phytosterols: beta-sitosterol, campesterol, stigmasterol, avenasterol and several dozen more.

The difference between one phytosterol and the next is small, usually one methyl or ethyl group on the side chain, or one extra double bond. That structural similarity is why they travel with fats, why they are measured in the oil fraction of a fruit rather than the juice fraction, and why any extraction method that removes oil also removes them.

They are not vitamins. The body does not have a stated requirement for them, and food composition tables classify them as a minor lipid component rather than a nutrient with a reference value. What they are, reliably, is a marker of whether a product still contains the fruit's oil.

Where in the berry do the sterols sit?

Sea buckthorn is unusual among fruits in carrying two chemically distinct oils. The soft orange flesh holds a pulp oil. The small seed inside holds a seed oil. They differ in fatty acid profile, in colour, and in sterol load, and treating them as one thing is the single most common error in writing about this berry. We cover the split in detail in pulp oil versus seed oil.

Sterols follow the seed. A published review of sea buckthorn oil composition and valorization reports total phytosterols in seed oil at 10,000 to 15,000 mg per kg, which is one to one and a half percent of the oil by weight, and puts pulp oil far lower at 1,000 to 3,000 mg per kg. The same review gives the sterol breakdown for the berry as beta-sitosterol at 60 to 70 percent of total sterols, campesterol at 15 to 25 percent, stigmasterol at 5 to 10 percent, and delta-5-avenasterol at 5 to 10 percent.

Work on supercritical carbon dioxide extraction from sea buckthorn seeds reports beta-sitosterol recovered at 576.9 mg per 100 g of oil using a petroleum ether reference method, and describes beta-sitosterol as the major sterol throughout the berry. Extraction method changes the recovered figure substantially, which is why published values for the same berry can differ by a factor of two or more.

How does that compare with other plant sources?

Sterol content is normally reported per 100 g of oil, not per 100 g of fruit, so the comparison here is oil against oil. Figures below are per 100 g of oil, drawn from a published review of vegetable oil composition and, for sea buckthorn, from the oil review cited above with its mg per kg values converted.

Oil	Total sterols, mg per 100 g oil	Beta-sitosterol, mg per 100 g oil	Source
Sea buckthorn seed oil	1,000 to 1,500	Not published as a single figure; 60 to 70 percent of total sterols	sea buckthorn oil review
Sea buckthorn pulp oil	100 to 300	Not published separately for pulp oil	sea buckthorn oil review
Rice bran oil	About 1,890	Not reported in the extract consulted	vegetable oil review
Corn oil	About 1,030	About 660	vegetable oil review
Rapeseed oil	About 890	About 390	vegetable oil review
Sesame oil	About 640	About 555	vegetable oil review
Sunflower oil	About 450	About 325	vegetable oil review
Soybean oil	About 450	About 360	vegetable oil review
Olive oil	About 290	About 150	vegetable oil review

Sea buckthorn seed oil sits within the range of common edible oils, comparable to corn oil and below rice bran oil. And beta-sitosterol is the dominant sterol in essentially all of them, so what makes sea buckthorn distinctive is the total load and the fact that it arrives alongside carotenoids and tocopherols, not the identity of the lead sterol.

The other comparison worth making is against the whole berry rather than the oil. Sea buckthorn is a fatty fruit by fruit standards. The Norwegian Food Composition Table publishes 5 g of fat per 100 g of raw berry, which is far above most fruit and is the reason a sterol conversation about this berry is worth having at all. In an apple or an orange there is essentially no oil fraction to carry sterols.

What does processing do to them?

Processing decides the number here more than the plant does.

Because sterols live in the oil, any process that separates oil from the rest of the fruit takes the sterols with it, in whichever direction. Pressing for clear juice discards the pulp and the seed, and with them the fat fraction and the sterols. A juice or a filtered concentrate is very low in sterols compared with whole puree or the oil fractions, regardless of how good the fruit was, and it is worth reading puree versus juice alongside this if you buy either.

A pressed whole puree keeps the pulp and the pulp oil in the finished product, so the sterol fraction stays where it started. The seed is a separate question. Whether seed oil is present in a puree depends entirely on whether the seed is crushed during pressing or removed first, and manufacturers rarely state this. If comparing products by sterol content, it is not published for most of them, and a nutrition panel will not tell you.

Heat and refining are the other two variables. Sterols are more robust to heat than carotenoids or vitamin C, a general finding in the lipid literature rather than a measured figure for sea buckthorn. But industrial refining steps used on commodity oils, particularly deodorisation, are documented to strip sterols from a finished oil. Cold-pressed and unrefined products retain more of what the seed carried. The processing question is covered further in cold-pressed versus freeze-dried.

What is not published?

Nobody publishes a reliable sterol figure per 100 g of whole fresh berry. Values are reported per unit of extracted oil, and the conversion depends on an extraction yield that varies with cultivar, ripeness and method. Anyone quoting a per-berry sterol number is inferring it.

Beta-sitosterol is reported as a percentage of total sterols for sea buckthorn far more often than as an absolute concentration in pulp oil specifically. The percentage is well established. The absolute pulp oil figure is not.

And there is no published sterol figure for any commercial sea buckthorn puree, including ours. What can be said is structural: a whole pressed puree retains the oil fraction that a juice discards, so it retains the sterols that fraction carries. That is a statement about processing, not a measured value.

Where this sits in a whole berry

Human Renaissance is the only sea buckthorn puree in the world sold in a single-serve pouch. 190+ naturally occurring compounds, omega 3, 6, 7 and 9, 201 mg of vitamin C per pouch, 0 g sugar, 5,640 hand-picked berries per box.

Sterols are one small part of that compound count, and they are there for the same reason the carotenoids and the omega 7 are there: the berry is pressed whole and the oil fraction is not filtered out. For the wider picture see sea buckthorn nutrition facts.

Frequently asked questions

Is beta-sitosterol the only sterol in sea buckthorn?
No. It is the dominant one, at 60 to 70 percent of total sterols in the published breakdown, alongside campesterol, stigmasterol and delta-5-avenasterol.

Does sea buckthorn juice contain phytosterols?
Very little. Sterols travel with the oil, and clear juice production discards the pulp and seed that hold it.

Which has more sterols, the pulp oil or the seed oil?
Seed oil, by a wide margin. Published values are 10,000 to 15,000 mg per kg for seed oil against 1,000 to 3,000 mg per kg for pulp oil.

How much phytosterol is in one pouch of puree?
Not published. No sterol figure exists for commercial sea buckthorn purees, and quoting one would mean inventing it.

The short version

Phytosterols are plant sterols carried in the fat of the fruit. Sea buckthorn carries them in both of its oils, and the seed oil holds roughly 3 to 15 times the concentration of the pulp oil, depending on cultivar and method. Beta-sitosterol dominates, at 60 to 70 percent of the total, which is also true of most edible oils. Sea buckthorn seed oil sits near the top of the range for common oils, close to corn and rice bran. The decisive variable is not the berry but the process: juice and filtered concentrate leave the sterols behind with the discarded pulp, while a pressed whole puree keeps the oil fraction and whatever it carries. Per-serving figures for finished products are not published.