EN ISO 2171:2023 PDF

Overview

EN ISO 2171:2023 - "Cereals, pulses and by‑products - Determination of ash yield by incineration" - is a CEN-endorsed international standard that specifies a laboratory method to determine ash yield (ash content) of cereals, pulses and their milled products intended for human consumption. The scope covers grains, flours and semolinas, bran and high‑bran products, mixed cereal flours, selected cereal by‑products (e.g., wheat gluten, maize grits, broken rice kernels) and pulse flours. It does not apply to starches and derivatives (see ISO 3593), animal feedingstuffs (see ISO 5984) or seeds.

Key topics and technical requirements

• Principle: Incinerate a defined test portion until organic matter is completely combusted and weigh the inorganic residue (ash). The document notes ash is flaky after incineration at (550 ± 10) °C and vitrified at (900 ± 25) °C.
• Recommended temperatures and materials:
  • Use (550 ± 10) °C generally for products with salts.
  • For flour analysis, 900 °C with platinum‑rhodium ashing dishes is recommended; quartz can be used at 550 °C (and as an alternative at 900 °C with caveats).
• Apparatus and reagents: electrically heated muffle furnace, grinding mill, ashing dishes (≥20 ml, ≥12 cm²), hydrochloric acid for cleaning, desiccant (purified P2O5 or silica gel), ethanol and high‑purity water.
• Procedure elements: sampling, grinding, preparation of test portions, pre‑ashing and ashing, moisture determination (linked to ISO moisture methods), number of determinations and expression of results.
• Quality parameters: the standard includes precision data from interlaboratory tests - repeatability, reproducibility, critical difference and guidance on uncertainty and test reporting.

Applications and who uses it

• Food testing laboratories performing compositional analysis and nutritional labelling.
• Millers and cereal processors for quality control (bran content, extraction rate verification).
• Ingredient suppliers and food manufacturers for product specification and acceptance testing.
• Regulatory bodies and trade laboratories for compliance and contractual disputes.
• Researchers studying cereal composition and processing effects.

Practical uses include monitoring raw material quality, verifying milling processes, establishing product specifications, and supporting labelling and safety/compliance programs.

Related standards

• ISO 712 - moisture reference method for cereals and cereal products
• ISO 6540 - maize moisture determination
• ISO 24557 - pulses moisture determination
• ISO 3593 - starches and derivatives (exclusion)
• ISO 5984 - animal feeding stuffs (exclusion)

Keywords: EN ISO 2171:2023, ash yield, ash content, incineration, cereals, pulses, flours, ashing, muffle furnace, platinum‑rhodium crucible, laboratory method.