Garlic Extract Adulteration and How Authenticity Is Proven

The Failure Mode That Is Not Adulteration

Most authenticity guides in this series are about things added or substituted. Garlic's principal quality failure is neither.

As covered in our standardisation guide, garlic works through a two-part system: alliin, the stable precursor, and alliinase, the enzyme that converts it to allicin on disruption. Alliinase is a protein, and heat denatures it.

So aggressive drying — faster, cheaper, higher throughput — produces a powder with:

• Perfectly respectable alliin content ✓
• Correct appearance, correct species, no filler ✓
• Little or no allicin yield ✗

Route 1 — Heat-Damaged Alliinase

Described above. Rarely deliberate deception; usually a processing economy that the buyer's specification failed to constrain.

What catches it:

• Allicin yield under stated conditions — the primary control.
• Alliinase activity reported as a separate parameter.
• Three consecutive batches compared — a supplier with gentle, controlled drying holds yield consistently; one working to throughput does not.

Route 2 — Undisclosed or Unrealistic Yield Conditions

The subtler version, and specific to how yield is measured.

Allicin yield depends on the buffer, pH, temperature and reaction time used in the assay. A supplier can report an impressive yield obtained under conditions optimised far beyond anything resembling use.

Nothing is falsified — the number is real under those conditions. It is simply not comparable to another supplier's figure, or predictive of performance.

What catches it: requiring the conditions stated on the certificate, and matching them when commissioning independent testing. A yield figure without conditions should be treated as no figure at all.

Route 3 — Culinary Powder Sold as Extract

The straightforward commercial substitution. Milled culinary garlic powder is genuinely garlic, produced at enormous scale for the food trade, and costs a fraction of an extract.

What catches it: the alliin assay, decisively — culinary powder cannot approach an extract's alliin content. This is the route where the content figure does its job well.

Prevention is better: state "extract" unambiguously in the purchase document, since this is frequently a specification ambiguity rather than a deception.

Route 4 — Aged Grade Substituted for Conventional (or Vice Versa)

A specification failure driven by genuine confusion between two chemistries.

Aged garlic extract is standardised on S-allyl cysteine and has essentially no allicin chemistry. Supplied against an allicin-yield specification it will fail spectacularly — and supplied against an odour-sensitive brief, a conventional extract will fail for the opposite reason.

What catches it: declaring the grade chemistry on the purchase order and requiring it on the certificate. SAC and allicin-yield figures are not interchangeable and should never be compared.

Route 5 — Allium Species and Carriers

The Allium genus includes onion, leek, chive and various wild relatives with overlapping sulphur chemistry. Substitution is less common than on some botanicals but the genus's chemical similarity means a crude sulphur-based check is not conclusive.

Alongside it, the usual undeclared carriers — maltodextrin, starch — diluting the material.

What catches it: species declaration by binomial, TLC and HPLC identity against authentic A. sativum reference, alliin on a dry carrier-free basis, a declared-carrier line, and acid-insoluble ash.

The Testing Package

Storage Degrades It Too

Worth flagging because it is not a supplier failure but produces the same outcome.

Heat degrades alliinase in your warehouse, just as it does in a dryer. A lot that arrived with good yield can lose it over months in a hot store — while its alliin content holds steady and reassures you falsely.

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

Practical Steps for a Buyer

1. Specify allicin yield with conditions, not alliin alone. The alliin figure cannot detect a dead enzyme.
2. Require alliinase activity as a separate reported parameter on yield grades.
3. Require yield conditions on the certificate and match them for independent testing.
4. Declare the grade chemistry on the purchase order.
5. Compare three consecutive batches on yield — it reveals drying discipline better than any audit.
6. Never specify allicin as an as-is content.
7. Store cool and re-test on yield, not alliin.

SV Botanica assays alliin by HPLC, determines allicin yield under stated conditions with alliinase activity reported, declares the grade chemistry on every batch, and supplies SAC-standardised aged grades. Buyer-nominated third-party pre-shipment testing is welcome — see the supplier evaluation guide, or the product specification.