Overview
ISO 10565:1998 specifies a rapid, laboratory method for the simultaneous determination of oil and water contents in commercial oilseeds using pulsed nuclear magnetic resonance (pulsed NMR) spectrometry. The method has been validated for rapeseed, soya (soy) beans, linseed and sunflower seeds with water contents below 10% (seeds with higher moisture must be dried before oil measurement). The technique records a free induction decay (FID) after a 90° RF pulse and a spin-echo after a 180° pulse; the echo amplitude is proportional to oil, and the difference between signals gives water content after calibration.
Key topics and requirements
- Scope & applicability: Intended for oilseeds whose oil is liquid at measurement temperature; validated on rapeseed, soya beans, linseed and sunflower seed.
- Principle: Pulsed NMR: 90° pulse → FID (total protons), 180° pulse → spin-echo (oil signal); calibrated conversion to % oil and % water.
- Instrumentation & consumables:
- Pulsed low‑resolution NMR spectrometer (manufacturer settings and precision requirements).
- Glass sample tubes, analytical balance (±0.01 g), drying oven (103 °C ±2 °C), desiccator, dishes.
- Calibration:
- Homogeneous, impurity‑free calibration samples (water <10% recommended).
- Minimum three calibration points (or procedures using one sample with varying fill heights).
- Calibration curve correlation coefficient normally > 0.95.
- Sample conditioning & measurement:
- Test room temperature 17–28 °C; condition samples ≥60 min.
- Use constant-volume test portions or prescribed fill heights; perform at least two determinations.
- Seeds with excessive moisture must be dried, reweighed and corrected for total water.
- Precision:
- Repeatability limits are provided per species (e.g., oil content repeatability ~0.4–0.8% m/m; water content repeatability ~0.2–0.3% m/m).
- Reproducibility values are stated in the standard and are generally higher than the drying reference method (ISO 665).
Applications and users
- Routine quality control for oilseed processing and crushing plants (incoming material checks).
- Laboratory analysis in seed testing, breeding programs and storage monitoring for moisture and oil content.
- Regulatory and commercial testing where rapid, non‑destructive simultaneous oil/water determinations are needed.
Keywords: ISO 10565, oilseeds, pulsed NMR, oil content determination, water content, rapeseed, soybeans, sunflower, linseed, seed quality control.
Related standards
- ISO 659 - Oilseeds - Determination of hexane extract (reference oil content method).
- ISO 665 - Oilseeds - Determination of moisture and volatile matter content (drying method).
- ISO 664 - Reduction of laboratory sample to test sample.
- ISO 542 - Recommended sampling methods for grain and seeds.
For laboratories implementing ISO 10565, follow manufacturer instructions for instrument parameters and perform routine calibration checks to ensure compliance with the standard’s precision and accuracy requirements.
Open preview (PDF)Oilseeds — Simultaneous determination of oil and water contents — Method using pulsed nuclear magnetic resonance spectrometry