Overview
EN ISO 734:2023 - titled Oilseed meals - Determination of oil content - Extraction method with hexane (or light petroleum) - is a CEN-adopted international standard (ISO 734:2023) that specifies a laboratory reference method for measuring the oil content (hexane- or light-petroleum extract) of oilseed meals. It applies to meals obtained from oilseeds by pressure or solvent extraction (excluding compounded products). This third edition (2023) updates the previous 2015 edition and includes safety clarifications for solvent handling.
Key topics and technical requirements
The standard defines the principle, reagents, apparatus, procedure and reporting needed for a reproducible solvent-extraction determination of oil content:
- Scope: Measurement of hexane (or light petroleum) extractable matter expressed as mass fraction (percentage), optionally relative to dry matter.
- Reagents: Use of technical hexane, n‑hexane or light petroleum meeting defined distillation and residue characteristics.
- Apparatus: Examples include mechanical grinder and microgrinder (Dangoumau type), extraction thimbles, straight-through extractors (Butt, Smalley, Twisselmann, Bolton‑Williams), rotary evaporator, electrically heated oven (103 °C ± 2 °C), desiccator.
- Procedure outline: sampling and test sample preparation (referencing ISO 5502), pre-drying (referencing ISO 771 for moisture), test portion and grinding, two-stage solvent extraction, solvent removal and weighing of extract, and calculation of oil content.
- Safety: Strong warnings - all reflux/boiling of solvent must be performed in a chemical fume hood and equipment must be suitable for flammable solvents.
- Quality & precision: The document includes requirements on number of determinations and provides data on repeatability, reproducibility and interlaboratory test results (Annex A).
- Reporting: Specifies the information that must be included in the test report.
Practical applications
This standard is a reference method used where accurate, comparable measurements of oil content in oilseed meals are required:
- Quality control in edible oil and animal feed production
- Purchase/sales specifications and lot acceptance testing for oilseed meal consignments
- Regulatory compliance and official testing laboratories
- Research laboratories studying oil extraction efficiency, meal composition, and processing effects
- Method validation and comparison against rapid or instrumental screening tests
Using EN ISO 734:2023 ensures consistent solvent-extraction results across laboratories and suppliers, aiding traceability and trade.
Who should use this standard
- Analytical chemists and laboratory managers in food, feed and oilseed industries
- Quality assurance and process control personnel
- National reference laboratories and certification bodies
- Researchers in oilseed processing and product development
Related standards
- ISO 771 - Oilseed meals: determination of moisture and volatile matter content
- ISO 5502 - Oilseed residues: preparation of test samples
Keywords: EN ISO 734:2023, ISO 734:2023, oilseed meals, oil content determination, hexane extraction, light petroleum, solvent extraction method, laboratory standard, CEN.