The Parameter Dictionary for
Dehydrated Potato Buyers

Typical causes are differences in sampling and sample preparation, different editions of the test method (for example AOAC 925.10 / ISO 712 for moisture or AOAC 963.19 for sulphite SO2), moisture pick-up during transport or storage, and measurement uncertainty. On the same lot, one laboratory may report moisture as-is at 8.6 % while another converts to dry basis and reports 9.4 % — the two numbers are not comparable unless the basis is stated. The contractual fix is to name one method edition, one accredited arbitration laboratory, the sampling plan and the decision rule for results sitting at the limit; then results become reproducible. On our technical data sheet every parameter row states the unit and basis, and the same discipline must appear in the potato flakes specification and its COA.

The values published here are authoritative references — USDA A-A-20032H, EU 1333/2008, Codex CXS 193-1995 and GB 2762 — that help you understand each parameter and the requirement of the destination market. For example, moisture for potato flakes is ≤ 9.0 % as-is under USDA A-A-20032H while granules are allowed ≤ 9.5 %; reducing sugars are capped at ≤ 4.0 %; residual sulphite SO2 is ≤ 500 mg/kg for flakes and ≤ 600 mg/kg for granules, but EU 1333/2008 limits dehydrated potato products to 400 mg/kg, so the stricter destination rule governs. Contractual limits, test methods and acceptance rules are fixed in the signed specification and verified by the lot COA. Where destination law is stricter than any reference, the law governs, so the potato flakes specification you sign should carry the destination value.

Write the full method reference with its edition — for example AOAC 925.10 or ISO 712 for moisture, AOAC 963.19 for sulphite SO2, ISO 6579 for Salmonella — plus the sampling plan, sample preparation, the accredited arbitration laboratory and the decision rule when a result sits exactly at the limit. State whether moisture is reported as-is or dry basis, because the same lot produces different numbers on the two bases. Add how measurement uncertainty is treated, since every result carries uncertainty from sampling and analysis. Verbal agreement cannot be enforced; only the signed potato flakes specification and its COA give you a defensible basis in a dispute.

A COA (Certificate of Analysis) is issued per production lot and must correspond to the physical lot shipped to you — it is a per-lot document, not a periodic one. Each COA reports the lot number, production date, test methods and results for moisture, reducing sugars, sulphite SO2, bulk density, particle size, microbiology and heavy metals. On arrival, your incoming inspection can re-test by the agreed method (for example moisture by AOAC 925.10 as-is) and compare with the certificate. If results diverge, the arbitration method and laboratory named in the specification decide, including how measurement uncertainty is treated.

A potato flakes COA typically includes the lot and production date, moisture as-is (≤ 9.0 % per USDA A-A-20032H), reducing sugars (≤ 4.0 %), residual sulphite SO2 (≤ 500 mg/kg, or ≤ 400 mg/kg for EU destinations), bulk density, particle size distribution on a defined mesh, water absorption, cold viscosity, gelatinization degree and free starch (blue value index) for pregelatinized grades, plus microbiology (APC < 100,000 CFU/g, Salmonella negative) and heavy metals checked against GB 2762 and Codex CXS 193-1995. Each field names the test method and its edition so the numbers can be compared with your potato flakes specification. Ask your supplier to attach the full technical data sheet and the signed COA before shipment.

Moisture is normally measured on the product as received (as-is) by drying to constant weight, typically by AOAC 925.10 or ISO 712, and reported in % w/w. Under USDA A-A-20032H, potato flakes must be ≤ 9.0 % as-is and granules / instant mash ≤ 9.5 % as-is. If a laboratory converts to dry basis, the number is higher (for example 9.0 % as-is is roughly 9.9 % dry basis) and must never be compared with an as-is limit. Always write the basis and the method edition next to the value in the technical data sheet, and specify the same basis in the potato flakes specification to avoid disputes.

Fry colour is driven mainly by reducing sugars (≤ 4.0 % per USDA A-A-20032H) and moisture; texture by water absorption, cold viscosity, gelatinization degree and free starch (blue value index); dosing and bag fill by bulk density and particle size mesh (sieve analysis) results. Food safety is covered by residual sulphite SO2 (EU 1333/2008: ≤ 400 mg/kg), microbiology (APC < 100,000 CFU/g, yeast & mould < 100 CFU/g for granules, Salmonella negative) and heavy metals per GB 2762 and Codex CXS 193-1995. Every one of these appears on the lot COA with its test method, so the technical data sheet and the potato flakes specification together close the loop.