Overview
EN ISO 17189:2003 (also published as ISO 17189:2003 / IDF 194:2003) is the reference method for determining fat content in butter, edible oil emulsions and spreadable fats (margarine, vegetable oil spreads, dairy spreads and blended spreads). Published by CEN in collaboration with ISO and IDF, this standard defines the solvent‑extraction principle, required reagents and apparatus, sample handling, calculation of results and performance characteristics (precision, repeatability, reproducibility).
Key topics and technical requirements
- Scope: Applies to butter and high‑fat edible oil emulsions (>75 % fat) and spreadable fats; reduced‑fat butters are treated as spreadable fats.
- Principle: Fat is extracted from a defined test portion with a specified solvent; solvent/fat phase is separated, transferred to a fat‑collecting vessel, solvent is removed by distillation/evaporation, and extracted mass is weighed.
- Extraction solvents: Petroleum ether (boiling range 30–60 °C) or n‑hexane (bp ~69 °C); solvents must pass an extraction‑solvent blank test.
- Reagents: Analytical grade only; ethanol ≥94 % v/v; optional Congo‑red indicator to aid phase separation (use with safety precautions).
- Apparatus & conditions:
- Analytical balance, readability 0.1 mg.
- Drying oven, 102 °C ± 2 °C.
- Fat‑collecting vessels (glass flasks 125 ml or metal dishes).
- Leak‑proof solvent‑resistant centrifuge tubes (50 ml), vortex mixer, centrifuge capable of 50–100 g.
- Distillation/evaporation apparatus or steam bath; automatic pipettor for quantitative transfer.
- Quality controls: Blank tests for method and extraction solvent; interlaboratory precision data, repeatability and reproducibility performance given in the standard.
- Safety & sampling:
- Warns about flammable solvents and hazardous reagents (Congo‑red may be carcinogenic).
- Sampling not included; ISO 707 recommended. Store samples at 5–14 °C until analysis.
Applications and who uses this standard
- Food testing laboratories performing official or reference analyses of butter, margarine and spreads.
- Dairy and edible‑oil manufacturers for product specification, quality control and formulation verification.
- Regulatory and certification bodies requiring an accepted reference method for compliance, labeling and trade.
- Research institutions studying fat composition, process effects or product development.
Using EN ISO 17189:2003 ensures comparability of fat content results across laboratories and supports compliance with food standards and labeling rules.
Related standards
- ISO 707 - recommended for sampling of milk and milk products (sample collection and handling).
- The method was developed jointly by ISO/TC 34, IDF and in liaison with AOAC; consult national implementations (EN ISO versions) for local status and endorsement.