Grape seed extract is the one botanical in this category where supplier qualification carries a food-safety dimension rather than only a commercial one. Peanut skin adulteration is documented, undeclared peanut is an allergen failure, and no certification, audit or facility allergen programme detects it — only an HPLC fingerprint does. This checklist is weighted accordingly, and it is deliberately unbalanced toward analytical capability.
Three Disqualifying Red Flags
- No HPLC fingerprint capability. On this ingredient that is not a nice-to-have. Without it a supplier cannot detect peanut skin or pine bark in their own incoming material — meaning they could pass an undeclared allergen to you in complete good faith. Decline.
- Assay method not stated on the CoA. As covered in OPC standardisation, a proanthocyanidin percentage without its method is uninterpretable. Suppliers who omit it are either not thinking about it or would prefer you did not.
- Cannot or will not provide a peanut-free declaration. A supplier who has not encountered this request has not supplied a customer with an allergen programme.
The one-question filter: "Do you screen your HPLC fingerprint against peanut skin and pine bark markers, and will you state that on the batch CoA?" A supplier who says yes without hesitation knows this ingredient's history. A supplier who is surprised by the question has not been in the serious end of this market — which is a complete answer, obtained for free, in one exchange.
The Scoring Framework
Weighted to 100 points, with authenticity capability carrying 35 — well above where a generic botanical checklist would place it. That weighting is deliberate: on grape seed extract, authenticity is a safety control.
1. Authenticity and Allergen Control — 35 points
| Criterion | Points |
|---|---|
| HPLC fingerprint against authentic Vitis vinifera seed reference material | 10 |
| Explicit peanut skin marker screen, result stated on the CoA | 9 |
| Explicit pine bark marker screen | 6 |
| Peanut-free declaration supplied as standard, not on request | 5 |
| Gallic acid / galloylation signature reported | 3 |
| Catechin : epicatechin ratio reported | 2 |
2. Assay Method Transparency — 20 points
| Criterion | Points |
|---|---|
| Proanthocyanidin assay method named on every CoA | 8 |
| Catechin, epicatechin and gallic acid reported by HPLC | 6 |
| Total polyphenols reported as a separate line, not as the assay basis | 4 |
| Assay stated on dry basis | 2 |
The third row is a genuine competence signal. A supplier who understands that a Folin figure is a different measurement — and reports it separately rather than presenting it as the OPC number — is a supplier who understands their own product.
3. Compliance and Contaminant Testing — 20 points
| Criterion | Points |
|---|---|
| Heavy metals by ICP-MS with numeric per-element limits | 5 |
| Ochratoxin A tested — relevant to the grape processing chain | 5 |
| Full USP microbiological panel including pathogens | 4 |
| EU pesticide MRL screening with a real report | 3 |
| Non-ETO declaration with LC-MS/MS available | 3 |
Ochratoxin A is weighted as a capability indicator as much as a safety one. It is specific to grape-derived material, and a supplier who tests for it without being asked has thought about where their raw material comes from.
4. Grade Capability — 10 points
| Criterion | Points |
|---|---|
| Multiple assay strengths and bases available | 3 |
| Oligomer-enriched / monomer-limited grade available | 3 |
| Low-colour cosmetic grade available | 2 |
| Seed specified explicitly (not "grape extract") | 2 |
5. Consistency and Commercial Terms — 15 points
| Criterion | Points |
|---|---|
| Three consecutive batch CoAs with consistent fingerprint and monomer profile | 5 |
| Origin and batch traceability to raw-material lot | 3 |
| Incoterms quoted properly to your named destination | 3 |
| Written payment terms on a proforma invoice | 2 |
| Technical questions answered by someone who understands the chemistry | 2 |
Interpreting the Score
| Score | Reading |
|---|---|
| 85–100 | Qualified for bulk supply. Proceed to sample and pre-shipment verification. |
| 70–84 | Workable with conditions. Close the gaps in writing before first bulk order. |
| 55–69 | Trial quantities only, with independent fingerprint verification on every lot. |
| Below 55 | Not a supplier for a regulated market. |
Apply a hard floor on section 1: below 20 of 35, decline regardless of the total. A supplier can be excellent on documentation, compliance and commercial terms and still be unable to tell you whether there is peanut skin in the drum. On this ingredient that single gap outweighs everything else, and no aggregate score should be allowed to obscure it.
The Sample Stage
- Ask for the fingerprint chromatogram with the sample, not just the numeric CoA. How readily it arrives tells you whether it genuinely exists as routine practice.
- Check the assay method appears on the sample CoA. If not there, it will not be on the bulk certificate.
- Check colour. Grape seed extract runs tan to reddish-brown. Strongly purple-red material may be skin-derived rather than seed.
- Taste a trace. Grape seed extract is markedly astringent. Material that is flat for its stated proanthocyanidin content merits a chromatogram.
- Does the sample dissolve cleanly? The standard grade should be water-soluble at typical use levels.
- Did they ask about your format? A supplier who does not ask whether protein is present in your system is not going to warn you about binding before you find it.
First-Order Protocol
- Nominate an independent laboratory — Eurofins, SGS or Intertek — for pre-shipment sampling. Put authenticity fingerprinting in the scope, not just assay. An independent OPC number reproduces exactly the blind spot the whole exercise exists to close.
- Ask the laboratory to use the same assay method as the supplier certificate. Otherwise an apparent discrepancy may be pure method difference.
- Compare the monomer profile across supplier and independent reports. If monomers agree but the class assay does not, the difference is methodological.
- Retain a sealed, dated sample for the shelf life of the material.
- Re-verify at batch three, then annually, and always on a change of manufacturing site or raw-material source. This ingredient has a documented history of supply chains changing badly.
- If you operate a peanut-allergen programme, list grape seed extract as a material requiring positive authenticity evidence and route its qualification through that programme rather than through general procurement alone.
SV Botanica supplies bulk grape seed extract from certified facilities in India with HPLC fingerprint screening against peanut and pine bark markers, the assay method named on every certificate, the monomer profile reported, ochratoxin A tested and a peanut-free declaration as standard documentation. Buyer-nominated third-party pre-shipment testing is welcome. See the product page, the buyer's guide, or adulteration and authenticity.
Source Standardised Grape Seed Extract from India
Proanthocyanidins NLT 95% with the method declared · monomer profile by HPLC · peanut & pine bark screened · CoA-backed · samples for qualified buyers