Purple red Grape Seed Extract 95% Oligomeric Proanthocyanidins (OPC) powder from Vitis vinifera seed

Grape Seed Extract 95% OPC / Proanthocyanidins

Grape seed extract is prepared from the seeds of Vitis vinifera left after pressing, and not from the skins, the leaves or the pressed seed oil. Ethanol extraction takes up the condensed tannins of the seed coat, and the liquor is dried to a purple red powder.

The grade is 95% oligomeric proanthocyanidins by UV, a colorimetric total. The powder is 80 mesh and slightly soluble in water. A single grade is supplied, which suits capsules, tablets and dry blends that need a high, defined polyphenol load in a small fill.

SKU: BOT-STX-0025 Category: Standardized Extracts Tags: Ethanol Extracted, Grape, Gummies & Chews, Polyphenols, Seed & Grain, Softgels & Oil Fills, Standardized Extracts

Proanthocyanidin Standardization & Grades

Proanthocyanidins are condensed tannins, chains of flavan-3-ol units such as catechin and epicatechin joined by carbon bonds. The oligomeric fraction, abbreviated OPC, covers the short chains from dimers to pentamers, and the grade reports the total proanthocyanidin content of the extract. Grape seed is the plant part in which these tannins are concentrated, and the seed is a by-product of juice and wine pressing, dried before extraction. The botanical entity is Vitis vinifera L., and the part used is the seed.

The grade is a single level at 95%, so the choice is between grape seed and other grape materials, not between tiers. Skin and wine extracts carry different pigments and tannins and are supplied separately, as the Grape Skin Extract 10–25% Anthocyanins and the Red Wine Extract 30–50% Polyphenols. The seed is also supplied as a 10:1 ratio extract, the Grape Seed Extract Powder, which carries no marker figure. The 95% figure is a very high total, and it makes grape seed extract a concentrate of tannin, not a whole-seed extract. Seed oil is a different product that contains none of these polar tannins. Grape seed extract also differs from the pressed seed in its sensory profile: the seed is hard, woody and oily, whereas the extract is a fine, astringent powder with the oil removed. The monomers catechin and epicatechin sit at the base of every chain, and the chain length decides how strongly the tannin binds protein.

Proanthocyanidin Analysis & Purity Risks

The figure is measured by UV, a colorimetric method. Common procedures heat the sample with an acid reagent that converts proanthocyanidins to colored anthocyanidins, and the absorbance is read against a reference. The result is a total, and it counts oligomers and polymers alike. It is not an HPLC result, and the abbreviation OPC on a label does not by itself say whether short chains only or all chain lengths were counted.

The reference material and the reagent define the number. A procedure that uses a different acid, a different temperature or a different standard gives a different percentage for the same extract, so a figure of 95% is comparable only to another figure obtained by the same procedure. HPLC is used beside the UV result to show the distribution of monomers, dimers and larger fractions, which identifies the seed as the source.

Sample preparation also matters. The powder is dissolved in a polar solvent, and tannins can stick to filters and glassware, so filtration losses are part of the method. Moisture in the powder changes the reading on an as-is basis, so the figure should be read together with the loss on drying.

Purity risks follow from the chemistry. Tannins bind proteins and metal ions, so a polyphenol extract gives strong color reactions with many interfering substances, and a high UV reading does not prove that the tannin came from grape seed. Seeds, skins and leaves of the grape give different tannin and pigment profiles, so a fixed part and a fingerprint help. Red grape pomace carries both seed and skin, and a mixed material would show anthocyanins that a pure seed extract lacks.

Typical Specifications

Specification Item	Product Information
Latin Name	Vitis vinifera
Plant Part	Seed & Grain
Processing	Ethanol Extraction
Compound Class	Polyphenols
Common Name	Grape Seed, Vitis Seed
Ingredient Type	Standardized Extract
Marker Compound(s)	Oligomeric proanthocyanidins (OPC, condensed tannins)
Primary Grade	95% OPC / Proanthocyanidins (UV)
Appearance	Purple Red powder
Solubility / Dispersibility	Slightly Soluble in Water
Quality Parameters
Moisture (LOD)	≤5.0%
Total Ash	≤5.0%
Particle Size	80 mesh
Heavy Metals	Lead ≤2 ppm · Arsenic ≤1 ppm · Cadmium ≤1 ppm · Mercury ≤0.1 ppm
Microbiology	TPC ≤1,000 cfu/g · Yeast & Mold ≤100 cfu/g · E. coli Negative · Salmonella Negative/25 g
Shelf Life	24 months in unopened original packaging, cool and dry storage

Applications by Grade

95% Grade for Dense Capsules

The 95% grade supplies a polyphenol dose in a small fill, which suits capsules and tablets. The tannin-rich powder is fine and astringent, so a glidant improves flow, and a dry filling room limits caking in the hopper.

95% Grade in Tablet Blends

Tablets of the 95% grade need a dry binder and a lubricant, because the powder is slightly hygroscopic and can stick to punches. Protect the tablet from iron-containing equipment, which darkens tannins on contact, and check for dark specks in the tablet face after compression.

Tannin Powder in Dry Blends

Dry blends use the powder for polyphenol content in small amounts. It is slightly soluble in water, so the mix leaves a haze or sediment in a drink, and the strong astringency needs sweetener or fruit solids to balance.

Grape Seed in Gummy Premixes

Gummy premixes take the powder in low doses. Tannins can bind pectin and gelatin, which stiffens or clouds the gel, so add the powder late and at a low temperature, and test the set and the clarity of the gel before scale-up.

Grape Seed in Softgel Fills

Softgel fills can carry the powder as a suspension in oil. The fine purple red solid does not dissolve in oil, so particle size and a suspending agent decide whether the fill stays uniform. Check the fill for settling after a week of storage.

Grape Seed in Stick Packs

Stick packs carry the powder with a flow agent and a sweet carrier. Seal the packs in moisture-barrier film, and expect a strong astringent taste when the stick is dissolved in water, which a fruit flavor or sweetener must cover. Test the dissolved drink for haze.

Technical & Quality Considerations

The extract is a purple red powder with a faint woody odor and a pronounced astringent and bitter taste. It is slightly soluble in water, and solutions are hazy and reddish-brown. Tannins bind proteins, so milk, gelatin and protein-based beverages can turn cloudy or form a precipitate. The same chemistry means that grape seed extract in a protein bar can harden the texture over time.

For production, sieve the powder before blending to break up soft agglomerates, and pre-blend it with a portion of the carrier so that it disperses evenly. Avoid contact with iron and copper, which form dark complexes with tannins. Use stainless steel or glass surfaces, and store the powder in a sealed liner, away from light, heat and moisture.

Polyphenols oxidize slowly in air and darken with time, especially at higher pH. Keep the drum closed between uses, compare each lot with a retained sample for color and taste, and run a stability test in the real base for any formula that contains protein or iron. Clean the line after a run, because tannin stains are persistent on plastic and steel. Taste is the main limit on dose in drinks, since an astringent mouthfeel builds up quickly in clear liquids and is only partly masked by sugar. A trial with the final sweetener and flavor system sets the usable level before the first production batch.

Packaging & Commercial Supply

Essencefield supports product evaluation, formulation trials, commercial orders, and ongoing ingredient supply. Packaging, storage, and shipping arrangements are determined by product characteristics, order quantity, stability requirements, and destination-market needs.

Supply Item	General Information
Sample	Available upon request for formulation, testing, and supplier evaluation
Order Quantities	100 g · 1 kg · 5 kg · 25 kg · 100 kg · 500 kg · Bulk
Sample Lead Time	Typically 5–7 days after sample confirmation
Production Lead Time	Typically 15–30 days after order and specification confirmation
Packaging	Suitable protective inner packaging with bags, cartons, drums, or other appropriate outer packaging
Storage	Store in tightly sealed, suitable protective packaging in a cool, dry environment. Protect from moisture, heat, and direct sunlight. Specific storage conditions follow the approved product specification.
Documentation	COA · Product Specification · TDS · SDS · Applicable declarations (as applicable)

Final order quantities, lead times, packaging, documentation, and shipping arrangements are confirmed according to the selected product and commercial requirements.