Overview
EN ISO 6647-1:2020 - Rice - Determination of amylose content - Part 1 specifies a reference spectrophotometric method for measuring the amylose mass fraction in milled (non‑parboiled) rice. The method is applicable to samples with amylose > 5% and can be extended to husked rice, maize, millet and other cereals if validated by the user. This CEN‑adopted ISO standard replaces the 2015 edition and aligns amylose values with PDO/PGI legislation comparability.
Key topics and technical requirements
- Analytical principle: finely ground rice is defatted, dispersed in sodium hydroxide, reacted with iodine and measured spectrophotometrically (absorbance of the amylose–iodine complex at 720 nm).
- Calibration: uses calibration solutions prepared from potato amylose and waxy rice amylopectin to correct for amylopectin effects on the iodine complex colour.
- Defatting procedure: methanol is used for defatting (the standard includes an 85% methanol reagent and describes defatting steps for potato amylose standard).
- Reagents and apparatus: specifies analytical‑grade reagents (e.g., methanol, ethanol, NaOH solutions, iodine solution, detergent) and standard laboratory equipment including a spectrophotometer.
- Quality and performance: provides procedures for preparing test and blank solutions, plotting calibration graphs and calculating results; includes sections on precision (interlaboratory testing, repeatability and reproducibility).
- Validation note: the method can be applied to other cereals only after the user validates the extension of scope.
Practical applications
- Quality control and classification of rice by amylose content (important for cooking and processing properties).
- Support for PDO/PGI compliance and labeling where amylose content is a defining characteristic.
- Routine testing in food testing laboratories, cereal research institutes and rice breeding programs to characterize starch composition.
- Use in product development (texture, processing behavior) and in supply‑chain assurance for rice processors and exporters.
Who should use this standard
- Food and cereal testing laboratories
- Rice breeders and agronomists
- Grain processing and milling companies
- Regulatory bodies and certification authorities monitoring PDO/PGI claims
- Research laboratories studying starch chemistry and cereal quality
Related standards
- ISO 712 - Moisture content of cereals (reference for sample moisture)
- ISO 8466-1 - Calibration and evaluation of analytical methods
- ISO 15914 - Enzymatic determination of total starch content
Keywords: EN ISO 6647-1:2020, amylose content, rice, spectrophotometric method, defatting, methanol, potato amylose, waxy rice amylopectin, 720 nm, PDO, PGI, cereal analysis.
