HIDROX® is an aqueous olive pulp extract (olive juice) produced during the processing of olives for oil extraction. The olive is the fruit of an evergreen olive tree (Olea europaea.) that grows in California, Italy, France, Spain, Greece, to name few.  Olive oil is extracted by a multi-stage process: crushing the pitted olives, kneading the resulting paste, collection of the free flow oil, pressure separation, collection of residual oil in the grinds, and separation of solids and aqueous fractions from the olive oil. The aqueous fraction separated is called “vegetation water”, which is rich in phenolic compounds, including hydroxytyrosol, oleuropein and tyrosol. HIDROX® is the trademarked name of preparations derived from the vegetation water. There are two preparations of HIDROX®: (A) a concentrated liquid standardized to 7.5% Total Polyphenols and 3% hydroxytyrosol (called HIDROX® 10X) and (B) freeze-dried powders standardized to 9% and 12% Total phenolics (HIDROX® freeze-dried powder 9% and 12%).  In the course of the past decades, we have produced scientific evidence that supports the general recognition that HIDROX® is safe for human consumption as a food ingredient under the intended conditions of use. (GRAS Certification).

HIDROX® is prepared from the aqueous fraction by-product that is produced during processing of olives for oil extraction. The term HIDROX® is a registered trademark that belongs to Oliphenol LLC  for its proprietary preparations of water-soluble polyphenols. Hydroxytyrosol (CAS No.10597-60-1), oleuropein (CAS No. 32619-42-4) and tyrosol (CAS No. 501-94-0) are the biologically relevant polyphenols present in HIDROX®.


General descriptive characteristics of HIDROXâ

Botanical source (Order) Oleales
Botanical family Oleaceae
Botanical name Olea europaea
Other names of botanical source Olive tree; Oliver; Olivenbaum; Oliva; Olea europea oil; Olea europea extract
Physical state Powder or liquid
Color Purple/brownish
Chemical family Polyphenols
Odor Processed olives
Taste Sour/olives
Packing and storage Preserve in tight containers and prevent exposure to excessive heat


The major phenolic constituents in HIDROX® preparations are hydroxytyrosol (35 to- 45%), oleuropein (5-10%), tyrosol (0.3%), oleuropein aglycone. In addition, Hidrox contains small amounts of gallic acid, vanillic acid, ferrulic acid and elenolic acid and other phytochemical present in olives.

Hydroxytyrosol (HT) also known as 3,4-dihydroxytyrosol or 3,4-dihydroxyphenylethanol, is a major component of the phenolic fraction of olive extract and olive oil. Because of its presence in virgin olive oil, hydroxytyrosol is frequently consumed as a dietary component. The presence of hydroxytyrosol has also been identified and quantified in wines. It is present either as simple phenol or esterified with elenolic acid to form oleuropein aglycone. Pure hydroxytyrosol is a clear, colorless, tasteless liquid and can be hydrosoluble or liposoluble. It greatly contributes to the shelf life of olive oil, preventing its autooxidation. The chemical formula and molecular weight of hydroxytyrosol are C8H10O3 and 154.16 g/mol, respectively.

Oleuropein is a bitter compound found in the bark, leaves and fruit of the olive tree, as well as in some other genera of Oleaceae. Oleuropein is a major component of unprocessed olive fruit, but table olives that are typically consumed are made more palatable by further processing that removes a vast majority of the oleuropein. The manufacture of HIDROX® similarly entails steps to convert the majority of the bitter oleuropein into hydroxytyrosol. Oleuropein has the chemical formula C25H32O13 and a molecular weight of 541 g/mol.

Tyrosol is a minor component of HIDROX®, which has a characteristic faint sweet fruity-floral odor and a subtle sweet taste. Tyrosol has the chemical formula C8H10O2 and a molecular weight of 138 g/mol.

Other constituents of HIDROX® include plant proteins, fat, and carbohydrates. As Hidrox® is maintained in its natural environment it also contains phytochemicals of the olive fruit that may contribute to the range of biological activity and health benefits of the product.

Chemical Identity of the Major Phenolics in HIDROX®

Hydroxytrosol: CAS 10597-60-1 – C8 H10 O3.  Molecular weight :154

Oleuropein : CAS 32619-42-4  – C25 H32 O13 –     Molecular weight:  541

Tyrosol : CAS 501-94-0  C8 H10 O2   Molecular weight:  138


Figure 1. Chemical Structure of Hydroxytyrosola


Figure 2. Chemical Structure of Oleuropeina

Oleuropein is a phenolic secoiridoid glycoside present in the bark, leaves, and fruit of Olea europaea. It is the most abundant phenolic compound in the drupe, constituting up to 14% of the fruit’s dry weight. In the intact olive, oleuropein is present in the glycosidic form but is partially hydrolyzed during olive oil production. A substantial proportion of oleuorpein remains in the olive mill wastewater (Soni et al., 2006a). The chemical structure is provided in Figure 2.


Figure 3. Chemical Structure of Tyrosola

Tyrosol is a minor component of HIDROX®, with a faint sweet fruity-floral odor and a weak sweet taste.

Aqueous Olive Pulp Extract (Hidrox®) is intended to be used as a food ingredient and as an antioxidant and antimicrobial in dietary supplements, cosmetics and skincare products, and selected conventional food categories, such as: bakery products; beverages; dairy products and substitutes; desserts; fats and oils; fruit juices and nectars; dry seasoning mixes for meat, poultry and fish; chewing gum; sauces, dips, gravies and condiments; snacks; and vegetable juices to deliver 5 to 10 mg of hydroxytyrosol per serving or more, as recommended by the EFSA , European Food Safety Agency.  The actual amount of Aqueous Olive Pulp Extract (Hidrox®) added (approximately 150 to 300 mg/serving) to the food categories will be adjusted such that the resulting addition corresponds to the proposed use levels of hydroxytyrosol.



The  Manufacturing of Hidrox(r).

Hidrox®, Oliphenol’s aqueous Olive Pulp Extract, is manufactured from a byproduct of olive oil processing.  We start from Organic olives grown in the San Joaquin Valley, California. The byproduct, called Pomace, is provided by a three-generation family owned business, the Patrick Ricchiuti Farms and Enzo Oil in Modesto. Organic olives are harvested in the fall/winter and transported to the olive oil process plant in large bins. The olives are transferred into a receiving hopper and then to a vibrating tray dry cleaner to remove olive leaves, stones, mud, and dirt. Following this step, the olives pass through a rotary washer, vibratory tray, and de-watering screen for removal of any small remaining debris. Subsequently, the olives are transferred to the crusher, which presses the olives into a minced pulp. Alternatively, olives can be processed to separate the olive pit from the pulp without crushing the pit. When olives go directly from the washer to the crushing devise (stone or hammer) a mix (slurry) of biomass, oil, emulsionated water (juice) and wood from pits is generated. Although the manufacturing hereby described is related to whole olives, similar results in producing Aqueous Olive Pulp Extract (Hidrox®) can be expected with olives that are pitted prior to the separation of olive oil and the remaining biomass, called “Pomace”..

The olive slurry is pumped into one of two double sets of warm water-jacketed cut-and-fold kneaders, where the pulp is gently stirred. The olive pulp is held at a warm temperature for approximately one hour to facilitate the separation of oil from the aqueous phase. Following this “kneading” process, the mixture is transferred into a horizontal centrifuge (decanter) where three fractions, olive oil, solid particles (or cake) and vegetation water (juice), are separated. The vegetation water (olive juice) generated from the decanter and collected into a separate reservoir and pumped into a vertical centrifuge to separate residual oil and large particulate solids from the vegetation water. Approximately 90-95% of the vegetation water is collected into large polypropylene totes and acidified with food grade citric acid to a specific pH range. The acid-treated olive juice is stored at room temperature for 6-8 months, where oleuropein is hydrolyzed to hydroxytyrosol and elenoic acid. This process is monitored by HPLC until a minimum conversion ratio of 5:1 is attained. The liquid is then subjected to gravity filtration to remove particulates, after which high-speed (ultra) centrifugation and filtration at 1 μm are used to remove non-soluble particulates. The resulting liquid (called Hidrox® 0.5%) is concentrated into a semi-viscous liquid using a low-temperature, high-vacuum evaporation process. The concentrate is standardized to 30 mg per kg (3%) hydroxytyrosol via aqueous dilution and called Hidrox® Liquid 10X.

For the freeze dried powder of the Aqueous Olive Pulp Extract, the 0.5 liquid preparation mention above (Hidrox® 0.5%) is used to produce two different standardized dry products. The first powder product is produced from freeze-drying the Hidrox® 0.5%, resulting in a powder consisting of 9% phenolic compounds (Hidrox® freeze-dried powder 9%). To produce the second powder product, the Hidrox® 0.5% is centrifuged and filtered to remove particulates and increase the phenolics content, followed by freeze drying. This results in a powder consisting of 12% phenolic compounds (Hidrox® freeze-dried powder 12%). The manufacturing flow chart is provided in Figure 3.

Aqueous Olive Pulp Extract (Hidrox®) is manufactured according to current good manufacturing practices (GMPs). The extract is produced at Specialty Concentrates, LLC, 9505 Rd. 301/2, Madera, CA. 93638, U.S.A. The FDA food facility registration number for the manufacturing facility is pr1144.

For the freeze-dried powder of the Aqueous Olive Pulp Extract, the 2.0% TP liquid preparation mentioned above (Hidrox® 2.0%) is used to produce a standardized dry product, called Hidrox Powder by freeze-drying of the Hidrox® liquid product. The  resulting product is a light brown powder consisting of 9 to 12% total phenolics (Hidrox 9% or 12% TP freeze-dried powder).

Hidrox® Stability.

HIDROX® has been shown through shelf-life stability studies that it is stable for 24-36 months when stored 25°C and 60% relative low humidity, if stored in well-closed containers and protected from light, excessive moisture and heat.

Oliphenol LLC has performed accelerated and long-term shelf-stability on representative lots of HIDROX®  Freeze-Dried Powder. Accelerated shelf-life samples were stored at 40°C and 75% relative humidity over a period of six months. Long term shelf-stability testing was also performed