Purple-red grape skin extract powder beside dark Vitis vinifera grape skins

Grape Skin Extract 10–25% Anthocyanins

Grape skin extract is prepared from the skin of red and purple wine grapes, Vitis vinifera, a by-product of juice and wine pressing, and the seed, stem and pulp are not part of the starting material. Ethanol extraction takes up the anthocyanin pigments and other phenolics of the skin, and the concentrate is dried to a purple-red powder.

Total anthocyanins are measured by UV with the pH differential method, with a primary grade of 25% and a lower grade of 10%. The powder is 80 mesh and water soluble. The 25% grade fits capsules and tablets that need a small fill, while the 10% grade fits drink powders and colored blends.

SKU: BOT-STX-0158 Category: Standardized Extracts Tags: Anthocyanins, Ethanol Extracted, Fruit & Berry, Grape, Gummies & Chews, Polyphenols, Standardized Extracts

Anthocyanin Standardization & Grades

Anthocyanins are the red, purple and blue pigments of grape skin, and in Vitis vinifera the main one is malvidin-3-glucoside, together with the 3-glucosides of peonidin, delphinidin, petunidin and cyanidin and their acylated forms. A UV pH differential assay adds them into one number. The botanical entity is Vitis vinifera L., and the grape skin extract is standardized to anthocyanins because they are the defining, colored phenolic class of the skin, in contrast to the seed, whose extracts are standardized to proanthocyanidins.

Grade	Assay & Method	Where It Fits
10% Anthocyanins	UV (pH differential)	Drink powders and colored blends
25% Anthocyanins	UV (pH differential)	Capsules and tablets, small fill weight

Grade choice follows dose, color and fill weight. The 25% grade carries two and a half times the anthocyanin load of the 10% grade per gram and a more intense color, so a capsule reaches its target with less powder, while the 10% grade is bulkier, lighter in shade and easier to blend. Grape is also supplied as a 10:1 ratio extract of the skin with no marker figure, the Grape Skin Extract Powder, and as other grape extracts: Grape Seed Extract 95% OPC / Proanthocyanidins from the seed and Red Wine Extract 30–50% Polyphenols from the wine. The standardized extract is the row to use when an anthocyanin figure has to appear in the specification.

Anthocyanin Analysis & Purity Risks

The pH differential method measures the absorbance of the sample at two pH values, typically 1.0 and 4.5. At pH 1.0 the anthocyanins are in the red flavylium form, and at pH 4.5 they are mostly colorless, so the difference in absorbance isolates the monomeric anthocyanins from other colored material. The result is expressed as an equivalent of a reference anthocyanin, commonly malvidin-3-glucoside or cyanidin-3-glucoside, and the reference moves the number. An HPLC result for individual anthocyanins cannot be converted into the UV value.

For identity, an HPLC fingerprint of the skin is read beside the total. Malvidin-3-glucoside dominates the pattern in Vitis vinifera, with peonidin, delphinidin and petunidin glucosides and their acetylated and coumaroylated forms, and the acylated share is a signature of the species. The data also records total polyphenols and low-to-mid resveratrol grades, which are followed in the fingerprint and are not stated as figures here.

Purity risks follow from the material class. Grape skin extracts can be made from different varieties and from different pressing stages, and the pigment profile varies with the variety, the year and the ripeness. American grape species such as Vitis labrusca have a different profile with diglucosides. The stated species and the stated skin part protect identity better than one percentage does. The pH differential method also reads polymeric pigments poorly, so a heavily aged skin material shows a low figure even though it is still colored.

Sample preparation uses an acidified alcohol extraction, because anthocyanins are most stable at low pH, followed by dilution into the buffer series and reading within a fixed window. Samples are protected from light and heat, since the pigments degrade quickly in neutral solution.

Raw material handling also matters. Pomace is separated and dried promptly, because wet pomace ferments and loses anthocyanin to enzymes and microbes. A quickly dried skin gives a deep purple extract, and a stale lot gives a dull, brown one.

Typical Specifications

Specification Item	Product Information
Latin Name	Vitis vinifera
Plant Part	Fruit & Berry
Processing	Ethanol Extraction
Compound Class	Anthocyanins, Flavonoids, Polyphenols
Common Name	Grape Skin, Red Grape Skin
Ingredient Type	Standardized Extract
Marker Compound(s)	Anthocyanins (malvidin-3-glucoside and related glucosides)
Primary Grade	25% Anthocyanins (UV, pH differential)
Available Grades	10% · 25% Anthocyanins (UV, pH differential)
Appearance	Purple Red powder
Solubility / Dispersibility	Water Soluble
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

25% Grade for Compact Capsules

The 25% grade of grape skin extract reaches an anthocyanin target in a small fill, which suits compact capsules. The purple powder is fine and hygroscopic, so fill in a dry room and seal the capsules in a desiccated bottle.

10% Grade in Acidic Drink Powders

The 10% grade dissolves into a bright red to purple cup whose shade depends on pH. Acidic bases with berry or grape flavors keep the red tone, while a neutral base turns the cup violet to blue-gray and fades faster.

25% Grade in Tablet Blends

Tablets of the 25% grade need a dry binder and a glidant, because the pigment-rich powder is hygroscopic and stains. A film coat limits dust and color transfer, and an opaque bottle protects the pigment from light.

10% Grade in Gummy Bases

Gummies take the 10% grade as a natural color and matrix contributor in red and purple fruit flavors. Add the grape skin powder after the main cook and keep the gel pH acidic, because heat and higher pH fade the anthocyanins quickly.

10% Grade in Sachet Premixes

For sachets, the 10% grade is blended onto a bulking carrier so that the filler can weigh a precise dose of the pigment-rich powder. Foil laminate with low moisture transmission and light protection keeps the grape skin powder free-flowing and the shade steady.

25% Grade in Stepwise Dilutions

Where a dose is small, the 25% grade is diluted in stages with a bulking carrier before it reaches the filler. The intense tint makes mixing uniformity easy to check by eye on a test batch.

Technical & Quality Considerations

Grape skin extract is a purple-red powder with a faint, winey, fruity odor and a tart, astringent taste. It is water soluble, giving a clear red to purple solution whose shade moves with pH. At low pH the anthocyanins are red, near pH 4 to 5 they fade almost to colorless, and above pH 7 they turn violet and blue and degrade rapidly.

Anthocyanins are among the least stable plant pigments. Heat, light, oxygen, ascorbic acid, sulfites and metal ions all shorten their life, and the acylated forms of grape are more stable than the simple glucosides. Iron and aluminium give blue-gray complexes, so stainless contact surfaces, low-iron fillers and opaque packaging hold the shade longer. Acidic pH is the single most effective stabilizer.

The pigment-rich powder is sieved and premixed with part of the carrier at scale, and early fills are weighed against target. The pigment stains hoppers and gloves, so use dedicated tools and a closed charging system. Drums are stored sealed and cool, away from light, with desiccant liners in humid regions.

Tannins that accompany the pigments bind proteins, so dairy-based or plant-protein drinks may haze, and a pilot batch at the target pH shows early whether a combination is sound.

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.