Overview
EN ISO 663:2017 - "Animal and vegetable fats and oils - Determination of insoluble impurities content" - is a CEN-endorsed adoption of ISO 663:2017. The standard defines a laboratory method to quantify insoluble impurities in animal and vegetable fats and oils using solvent extraction, filtration and gravimetric weighing. It excludes milk and milk‑derived fats, and notes that if soaps (e.g., calcium soaps) or oxidized fatty acids should be excluded from the result, an alternative solvent/procedure must be agreed between parties.
Key topics and requirements
- Scope: Applies to animal and vegetable fats and oils (milk fats excluded).
- Principle: Dissolve a weighed test portion in excess n‑hexane or light petroleum, filter the insoluble residue, dry at 103 °C and weigh the residue to calculate percentage insoluble impurities.
- Test portion & reagents: Typical test portion ~20 g; solvent options are n‑hexane or light petroleum (30–60 °C distillation range, residue ≤ 0.002 g/100 ml). Kieselgur (purified, calcined) is specified for coating crucibles when analysing acid oils.
- Apparatus: Analytical balance (±0.001 g), oven (103 °C ±2 °C), desiccator, ashless filter paper or glass‑fibre filter, or a glass filter crucible (grade P16, 10–16 µm).
- Procedure highlights: Add ~200 ml solvent, stand ~30 min, filter, rinse and evaporate solvent, dry filter/crucible at 103 °C, cool in desiccator and weigh. For organic impurity content, ignite the filter and subtract ash.
- Precision & reporting: The standard includes clauses on repeatability, reproducibility and results of interlaboratory tests, and specifies required information for test reports.
- Safety: Handling of flammable/dangerous solvents is emphasized; use recognized analytical‑grade reagents.
Applications and users
EN ISO 663:2017 is used for:
- Quality control and acceptance testing in edible oil and fat production lines.
- Routine laboratory testing by food testing labs, refineries, oilseed processors and trade laboratories.
- Regulatory compliance, specification verification and dispute resolution between suppliers and buyers (note the requirement to agree if excluding soaps/oxidized fatty acids).
- Research labs assessing oil purification and refining efficiency (e.g., residue removal).
Typical users: laboratory analysts, quality managers in edible oil/animal fat industries, food safety authorities, standards and compliance officers.
Related standards
- ISO 661 - Preparation of test sample (referenced normative).
- ISO 5555 - Recommended sampling methods (sampling not part of ISO 663).
- Other ISO/CEN methods for fats and oils quality control (see the document bibliography).
Keywords: EN ISO 663:2017, insoluble impurities, animal and vegetable fats and oils, n‑hexane, light petroleum, filter crucible, kieselgur, laboratory method, quality control.
