Garlic Extract: A Complete Buyer's Guide

The Reaction That Explains Everything

An intact garlic clove contains two things kept deliberately apart by the plant:

• Alliin — a stable sulphur amino acid, sitting in the cell cytoplasm.
• Alliinase — an enzyme, sequestered in a separate compartment.

Crush, cut or chew the clove and the compartments rupture. Alliinase meets alliin and converts it to allicin within seconds. That reaction is the smell of garlic — an intact clove is nearly odourless, and it is the cutting that makes a kitchen smell of garlic.

Allicin is then unstable, degrading over hours into secondary sulphur compounds — ajoene, vinyldithiins and others.

What to Specify Instead

Allicin yield — also called allicin potential or allicin-releasing capacity — is the most informative single figure, because it captures both halves of the system. Two powders with identical alliin can differ substantially in yield if one has had its alliinase damaged by heat. Yield tests the precursor and the enzyme together.

Insist the conditions be stated. A yield figure without its assay conditions is not comparable between suppliers.

The Formulation Consequence Nobody Mentions

Here is where a correct specification can still fail to deliver.

Alliinase is acid-labile. Stomach acid inactivates it.

So if an uncoated garlic tablet dissolves in the stomach, much of the enzyme is destroyed before it can convert alliin to allicin — and the allicin actually delivered falls well short of the yield figure on your certificate. The specification was true; the format defeated it.

This is why serious allicin-yield products are enteric-coated. The coating carries the material past the stomach so the reaction can happen where the enzyme survives. The enteric coat is not a refinement — it is what makes the yield claim true.

If your format cannot be enteric-coated — a gummy, a beverage, a chewable — an allicin-yield claim is hard to defend, and an alliin basis or aged garlic is the more honest route.

Aged Garlic Is a Different Product

Worth understanding as a genuine alternative rather than a grade.

Aged garlic extract is produced by a long maturation that converts garlic's reactive sulphur compounds into stable, water-soluble, largely odourless derivatives — chiefly S-allyl cysteine (SAC), which becomes the standardisation marker.

An SAC figure and an allicin-yield figure are not comparable. They describe different chemistries. Choose one deliberately.

Extract Versus Culinary Powder

The most common substitution, and often a specification failure rather than a fraud. Milled culinary garlic powder is genuinely garlic, cheap, abundant — and a fraction of an extract's concentration.

What catches it: the alliin assay, decisively. Culinary powder cannot approach an extract's alliin figure. State "extract" unambiguously in the purchase document.

What a Genuine Garlic CoA Must Show

Storage Affects Your Specification

Unusual and worth planning for: heat degrades alliinase. So a material bought on allicin yield can lose yield in a warm warehouse while its alliin content holds steady.

If you buy on yield, keep stock cool and re-test long-held lots on yield rather than on alliin — the alliin figure will reassure you falsely. Same structural lesson as gingerols and HCA: check the parameter that actually moves.

Garlic's odour also travels. Store away from odour-sensitive stock.

A Labelling Note

Garlic is commonly flagged in consumer and healthcare guidance for potential interaction with anticoagulant and antiplatelet medication, often with advice around surgery — the same consideration that applies to ginkgo. Advisory labelling is standard practice in many markets; the specific requirement belongs in your regulatory review.

What to Ask Your Supplier

1. Alliin by HPLC, on dry basis
2. Allicin yield with the assay conditions stated
3. Alliinase activity for yield grades
4. Grade chemistry declared — alliin, yield or aged
5. S-allyl cysteine for aged grades
6. Extract or culinary powder, unambiguously
7. Species by binomial, bulb specified
8. Heavy metals by ICP-MS with numeric limits
9. Pesticide residue against EU MRL

Our companion garlic supplier evaluation guide turns this into a scored checklist. SV Botanica states the grade chemistry, the alliin figure and the allicin yield with its conditions on every certificate.