Purity, admixture and volatile oil are three different promises. Here is what each grade of Indian cumin commits the supplier to, and where disputes usually start.
Most cumin disputes are not about fraud. They are about two parties reading the same grade name differently.
Purity is not the whole specification
“Singapore 99%” tells you that 99% of the lot by weight is cumin seed and 1% is extraneous matter. It says nothing about moisture, nothing about volatile oil, and nothing about pesticide residue. A lot can be perfectly 99% pure and still fail a European MRL panel.
Where the grades actually differ
Singapore Quality sits at 99% purity with 1% admixture and is the volume grade for the Gulf, South-East Asia and North Africa. Europe Quality tightens purity to 99.5% and, more importantly, is selected from fields and lots screened against EU maximum residue limits. Sortex 99.9% is machine-sorted a further pass, mainly for colour uniformity and stone removal.
What to put in your contract
Name the purity grade, then state moisture, total ash, acid insoluble ash and volatile oil as separate numbers. If you sell into the EU, name the MRL panel you test against. If colour matters to your retail pack, say so — it is not implied by any purity grade.
A supplier who cannot give you those numbers before shipment is quoting on hope.
