ISO 5529:2007

Overview

ISO 5529:2007 - "Wheat - Determination of the sedimentation index - Zeleny test" defines a laboratory method (the Zeleny sedimentation test) for assessing a key quality attribute of wheat (Triticum aestivum L.). The test measures the sedimentation index - the volume (mL) of sediment formed when a precisely prepared test flour is suspended in an acid–alcohol medium - and is used to help predict the baking strength of flour produced from the wheat.

Key topics and technical requirements

• Scope: Applicable only to Triticum aestivum L. wheat for prediction of flour baking strength.
• Principle: Protein swelling in an acid medium produces a sediment whose volume correlates with gluten quality and baking performance.
• Reagents: Includes lactic acid (stock solution prepared by refluxing and titration to a defined molarity), propan-2-ol (isopropanol), bromophenol blue dye and standard titrants/indicators. The standard specifies reagent grades and storage/use windows (e.g., test solution use 48 h to 15 days after preparation).
• Apparatus: Typical lab equipment plus specified items such as test mills (see Annex A), a 150 µm sieve (ISO 565), 100 mL graduated flat-bottom cylinders, a timed cylinder shaker, pipettes (ISO 648), and analytical balances.
• Test flour preparation: Grinding and sieving conditions are specified (particle size