SIST EN ISO 27971:2023 PDF

Overview

EN ISO 27971:2023 specifies a standardized method for determining the alveograph properties of dough made from common wheat (Triticum aestivum L.) flours - from both commercial and laboratory-milled test flours - at constant hydration. Published by CEN / ISO, this standard defines sample preparation, laboratory milling methodology and the Alveograph test procedure to assess dough rheology for quality control, research and product development.

Key topics and technical requirements

• Scope and principle
  • Measurement of dough rheological behavior using an Alveograph under constant water addition.
  • Applicable to flour produced by industrial milling or by a defined laboratory milling procedure.
• Laboratory milling methodology
  • Two-stage mill workflow:
    • Stage 1 - prepare wheat to facilitate bran/endosperm separation (cleaning, conditioning).
    • Stage 2 - milling: breaking (three fluted rollers), reduction (two smooth rollers), and grading using a centrifugal sieving machine.
  • Conditioning rules based on initial grain moisture: one-stage moistening for 13–15 %, two-stage moistening for <13 %, preliminary drying then moistening for >15 %.
• Alveograph test procedure
  • Detailed steps for kneading, patty preparation, and biaxial extension using the Alveograph instrument.
  • Parameters defined and reported: P (maximum pressure), L (mean abscissa at rupture), G (swelling index), I (elasticity index), P/L ratio, and W (deformation work).
• Quality and performance
  • Precision data: repeatability and reproducibility limits from interlaboratory tests.
  • Requirements for sampling, storage, test reporting and uncertainty estimation.
• Supporting annexes
  • Guidance on suitable laboratory mills, conditioning water quantities, milling sheets, conversion tables, maintenance, and proteolytic activity assessment.

Applications and users

EN ISO 27971:2023 is used by:

• Flour and milling laboratories for quality control and production monitoring.
• Baking industry R&D for dough performance and formulation optimization.
• Cereal breeders and agronomists evaluating wheat quality traits for processing.
• Standards bodies and testing laboratories conducting proficiency testing and method validation.

Practical benefits include consistent, comparable alveograph data for assessing dough strength, extensibility and baking performance - essential for product specification and ingredient selection.

Related standards

• Developed by ISO/TC 34 and CEN/TC 338; supersedes EN ISO 27971:2015.
• Often used alongside other cereal testing standards (moisture, protein, falling number) for comprehensive wheat and flour characterization.

Keywords: EN ISO 27971:2023, alveograph, dough rheology, laboratory milling, common wheat, flour testing, Alveograph test, constant hydration.