Overview
EN ISO 15301:2001 specifies a standardized centrifuge method for the determination of sediment in crude animal and vegetable fats and oils. The procedure isolates and volumetrically measures the sediment fraction that can be separated by centrifugal force, providing a repeatable test appropriate for quality control, trade monitoring and laboratory acceptance testing.
Key practical points from the standard:
- Applicable to crude oils and oils with a sediment content from 0,03 ml/100 g to 15 ml/100 g.
- Not applicable to fats that are not liquid at 20 °C.
- Uses calibrated 100 ml pear- or cone-shaped centrifuge tubes and buckets resistant to fats and oils.
Key Topics
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Sample preparation: Follow ISO 661 for preparation of the test sample and ensure homogenization. Bring the sample to about 20 °C (±2 to 5 °C where necessary) and redisperse any settled material to obtain a representative aliquot.
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Test portion and weighing: Transfer 100 ml of prepared sample into two centrifuge tubes and record tube masses before and after filling (to 0,1 g accuracy).
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Centrifugation conditions: Apply a radial acceleration of 700 to 800 times gravity (g) at the narrow part of the tube. Centrifuge for 1 h ± 5 s. Maintain room/centrifuge temperature between 20 °C and 25 °C when air-conditioning is not available.
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Reading and expression of results: Measure the sediment volume volumetrically in the calibrated tube. Read volumes up to 1,5 ml to the nearest 0,03 ml, and volumes greater than 1,5 ml to the nearest 0,5 ml. Calculate sediment content (ml per 100 g) using the measured sediment volume and tube masses as specified in the standard.
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Records and reporting: Record centrifuge speed/acceleration, swing diameter, temperatures before and after centrifuging, and any operational deviations. Report the mean of two determinations.
Applications
- Routine quality control for crude vegetable and animal oil processing and refining.
- Contractual and trade testing where sediment limits affect product acceptance.
- Laboratory method for monitoring extraction/crushing process performance and crude oil cleanliness.
Benefits:
- Rapid separation compared with long settling methods (96 h alternative).
- Standardized, reproducible volumetric measurement suitable for interlaboratory comparison.
Related Standards
- ISO 661:1989 - Preparation of test sample (referenced normative document).
- ISO 5555 - Recommended sampling practices (sampling guidance referenced).
- ISO 5725-2 - Used for interlaboratory precision assessment (referenced in Annex B).
For implementation, consult the full EN ISO 15301:2001 text for detailed apparatus drawings, the calculation annex and precision data from interlaboratory studies.
