Maca Adulteration and How Authenticity Is Proven

Four Incentives, All Pointing the Same Way

Adulteration follows economics, and on maca the economics are unusually consistent:

Each route is independently worthwhile to a dishonest seller, and they combine.

Route 1 — Starch and Flour Bulking

The easiest. Maca is a starchy root powder, cream to light beige — so rice flour, maize starch, maltodextrin and similar blend in invisibly, matching colour, texture and flow.

What catches it:

• Macamides by HPLC — bulking dilutes them proportionally, and unlike glucosinolates they cannot be contributed by a filler.
• Total and acid-insoluble ash, plus a declared-carrier line by name and percentage.
• Assay on a dry, carrier-free basis.
• For gelatinised grades, a starch figure — bulking with starch is obvious against a specification that limits it.

Note the neat interaction: gelatinised maca is defined by starch removal, so on that grade a starch specification does double duty as both a processing check and an anti-bulking control.

Route 2 — Non-Maca Brassicaceae Material

The route that follows directly from the marker problem set out in our standardisation guide.

Glucosinolates are the defining feature of the entire cabbage family. Material from cheaper crucifers — or from other Lepidium species — can therefore contribute to a glucosinolate assay without any maca being present.

What catches it: macamides, decisively. They are essentially unique to Lepidium meyenii, so no amount of other crucifer material brings them along. A material meeting its glucosinolate specification with absent or low macamides has answered the question.

Route 3 — Phenotype Substitution

Yellow maca supplied against a red or black specification. Profitable, because yellow is by far the most abundant and least expensive while red and black carry real premiums.

Analytically this is harder than the other routes, and it is worth being honest about that. Phenotype differences are pigment and secondary-metabolite differences rather than a clean marker distinction, so no single assay cleanly separates them.

What catches it — realistically:

• Colour against the declared phenotype. Yellow is cream to light beige, red pale pink-beige, black grey-beige to light brown. Crude, but the first check.
• A per-batch phenotype declaration, converting an assumption into a written representation.
• Supply-chain control — a supplier who segregates phenotypes at source rather than sorting later.
• Three consecutive batches compared for colour consistency; a "red" that drifts toward cream across lots is telling you something.

Because the analytical control here is weaker than elsewhere, the documentary and supply-chain controls carry more weight. Buyers paying a phenotype premium should qualify the supplier's segregation practice specifically.

Route 4 — Origin Misrepresentation

"Peruvian maca" is a meaningful provenance statement carrying a genuine premium, and Peru maintains protections around maca germplasm and raw material reflecting its status as a native crop of national importance.

Maca is now also grown elsewhere, which is not itself illegitimate — but selling non-Peruvian material as Peruvian is.

What catches it: primarily documentary chain rather than analysis — origin declarations, shipping and import documentation, and a supplier who can describe their chain rather than assert an origin.

Ask directly whether the supplier is an origin producer or a merchant/exporter. Both are legitimate; vagueness about which is not.

Route 5 — Raw Sold as Gelatinised

Gelatinised maca commands a premium for its improved digestibility and dispersion. Raw material relabelled captures that premium at no cost.

What catches it: the starch figure, cleanly. Gelatinisation is defined by starch removal, so a "gelatinised" material carrying raw-maca starch content has not been gelatinised. This is one of the few adulteration questions in the whole series with a clean quantitative answer.

Dispersion behaviour is a useful informal check too — gelatinised material disperses noticeably better.

The Testing Package

Practical Steps for a Buyer

1. Require macamides by HPLC on every batch. The one line that addresses the two hardest routes.
2. Never rely on glucosinolates for identity. It is a Brassicaceae marker, not a maca one.
3. Require a starch figure on gelatinised grades. Clean quantitative evidence of processing.
4. Qualify phenotype segregation at source if you pay a phenotype premium — the analytical control here is weak, so the supply-chain control has to be strong.
5. Ask producer or merchant, and require origin documentation rather than assertion.
6. Compare three batches for colour consistency on premium phenotypes.
7. Third-party verify with macamides in scope. An independent glucosinolate figure reproduces the blind spot exactly — it would be satisfied by broccoli.

SV Botanica reports macamides by HPLC on every maca batch, declares Peruvian origin, colour phenotype and processing status, and reports starch on gelatinised grades. Buyer-nominated third-party pre-shipment testing is welcome — see the supplier evaluation guide, or the product specification.