Oleuropein
Oleuropein is a secoiridoid glucoside and the principal phenolic constituent of the olive tree, Olea europaea, occurring in the leaf at up to several percent of dry weight and in the unripe fruit at high concentration. It is an ester of elenolic acid glucoside with hydroxytyrosol, and that structure explains both its properties and its instability: the ester bond hydrolyses and the glucose is cleaved by beta-glucosidase, releasing hydroxytyrosol and oleuropein aglycone.
It is the compound responsible for the intense bitterness of raw olives, and traditional olive curing in brine or lye exists precisely to break it down. In ingredient form it is sold for the opposite reason, as the assayed active of olive leaf extract used in supplements and functional foods.
Purified material is an off-white to pale yellow amorphous powder, soluble in water, methanol and ethanol and poorly soluble in oils. In solution it is most stable in mildly acidic conditions and degrades above neutral pH, at elevated temperature and in the presence of the glucosidase naturally present in unblanched leaf, which is why leaf destined for extraction is heat treated soon after harvest. The catechol group also oxidises and browns on exposure to air and metal ions.
We source bulk Oleuropein from top China manufacturers for our partners. The manufacturers are in Shaanxi. A smaller requirement can ship in a combined container with other ingredients.
Please send the grade you need, the volume and your destination port, and we will come back with a solution and a price.
or call +86-21-6858 0751
- Function
- Plant extract
Specifications
| Item | Specification |
|---|---|
| Appearance | Off-white to pale yellow amorphous powder with bitter taste |
| Oleuropein (HPLC, dry basis) | 98.0 percent minimum |
| Identification | HPLC retention and UV maximum near 232 and 280 nm conform to reference |
| Hydroxytyrosol | 1.0 percent maximum |
| Verbascoside | 0.5 percent maximum |
| Loss on drying | 5.0 percent maximum |
| Residue on ignition | 1.0 percent maximum |
| pH (1 percent aqueous solution) | 4.0 to 6.0 |
| Residual solvents (ethanol) | 5000 mg/kg maximum |
| Lead | 1.0 mg/kg maximum |
| Arsenic | 1.0 mg/kg maximum |
| Total plate count | 1000 cfu/g maximum |
| Escherichia coli | Absent in 10 g |
| Salmonella | Absent in 25 g |
Common Markets Grades
The trade runs from standardised olive leaf extract to purified compound. Olive leaf extracts standardised to 6, 10, 20, 40 or 60 percent oleuropein by HPLC make up most of the volume, with total polyphenol content quoted alongside. Purified oleuropein at 80, 90 and 98 percent is produced in smaller quantity for reference and high-specification supplement use. Hydroxytyrosol-enriched grades are a separate article, made by deliberately hydrolysing oleuropein, and should not be confused with it.
Buyers should check the assay method, since colourimetric total-polyphenol figures come out considerably higher than the HPLC oleuropein figure for the same material, and some extracts are standardised on total oleuropein and related secoiridoids rather than on the parent compound. Water and aqueous ethanol extracts are both traded, along with olive fruit extracts made from vegetation water, which have a different polyphenol distribution. Organic certified leaf and extracts are available.
Applications
- Olive leaf extract supplements in capsule and tablet form, standardised on oleuropein
- Cardiovascular and blood pressure support formulas
- Immune support blends, a traditional positioning for olive leaf
- Functional beverages and shots, formulated at mildly acidic pH to hold the glucoside
- Antioxidant addition to oils and fat-containing foods, where the polyphenol slows oxidation
- Nutricosmetic products and skin care formulations positioned on antioxidant claims
- Sports nutrition and recovery blends alongside other polyphenols
- Feedstock for hydroxytyrosol manufacture by enzymatic or acid hydrolysis
- Analytical reference standards for olive polyphenol quantification and for olive oil authenticity work
Brands Using Oleuropein
Widely-distributed consumer products that list Oleuropein on the ingredient label.
Brand names, product names and logos are the property of their owners. They appear here as published evidence that the ingredient is used, taken from the brand's own label or website. Their appearance is not an endorsement, and it does not mean the brand buys from us or from any manufacturer listed on this site.
China Manufacturers of Oleuropein
Top Oleuropein manufacturers in China.
- Focusherb Corp.6 ingredients in the directory
Sanyuanlihua Bio-tech Co., Ltd.13 ingredients in the directory
Company names and logos are the property of the manufacturers themselves. They are listed here because our own directory records them as producing this ingredient. A listing is not an endorsement by them, and we do not represent them or speak on their behalf.
Regulatory Status
In the United States olive leaf extract is used as a dietary ingredient in supplements, and olive fruit polyphenol preparations have been the subject of GRAS notifications for use in foods and beverages at defined levels. There is no food additive regulation naming oleuropein itself, and a supplier of the purified compound should be able to document the basis on which it is offered, particularly where it is destined for conventional food rather than supplement use. Claims are structure and function claims subject to the usual substantiation and disclaimer requirements.
In the European Union olive leaf preparations are used in food supplements under national botanical rules, while olive polyphenol extracts from fruit and vegetation water have been assessed in the context of the authorised health claim relating olive oil polyphenols to the protection of blood lipids from oxidative damage, which is expressed in terms of hydroxytyrosol and its derivatives including oleuropein complex and applies to olive oil rather than to isolated extracts. Highly concentrated or purified preparations may require novel food assessment. There is no E number. Codex has not adopted a specification for oleuropein; the general Codex provisions on contaminants and hygiene for plant material apply, and the Codex standard for olive oils addresses the parent commodity.
Manufacturing Process
Olive leaf is collected from pruning and from the leaf fraction separated during olive oil milling, then cleaned of twigs and soil. It is blanched or dried quickly in warm air, and this is the critical control: fresh leaf carries an active beta-glucosidase that will cleave oleuropein within hours if the leaf is allowed to sit damp, so the enzyme has to be denatured or the moisture removed before extraction. Dried leaf is milled to a coarse grade.
Extraction is carried out with water or aqueous ethanol, usually 50 to 70 percent, at moderate temperature in a multi-stage countercurrent system, kept short to limit hydrolysis. The extract is filtered, the alcohol recovered under vacuum, and the aqueous concentrate loaded onto macroporous adsorption resin, which binds the phenolics while sugars, salts and mannitol pass through; graded alcohol elution then recovers an oleuropein-rich fraction. For purified grades the eluate goes on to preparative or simulated moving bed chromatography to resolve oleuropein from verbascoside, luteolin glycosides and oleuropein aglycone. The purified solution is concentrated under vacuum at low temperature and spray dried or freeze dried, then sieved and packed under nitrogen away from light and heat.
