Oil, Protein and Moisture Determination in Seeds Using NMR

We can now test seeds for oil, protein, and moisture content using NMR spectrometry, a non-destructive technology.

What is NMR is used for?

Nuclear Magnetic Resonance Spectrometry (NMR), is used for determining oil, protein, and moisture content in seeds of various oil crops. The instrument is calibrated for several oil crops including soybean, camelina, canola, meadowfoam, and euphorbia, and can be calibrated for other species as needed. Tests can be performed in whole seeds or meals.

The need for NMR

meadowfoam-fieldWith the diversification of crops in Oregon and the search for crops to be used for biodiesel production, the need to determine the oil content of such crops has emerged. In addition, the meal in some oil seeds, such as soybean, is used for feed after extracting the oil and it is useful to determine the protein content in the meal as well as in the seeds. Both the USDA and Canadian Grain Commission use NMR in determining oil seed content in oil crops.

In the past, researchers have had to send their oil seeds out-of-state for oil and protein analysis. The OSU Seed Laboratory’s recent acquisition of a Nuclear Magnetic Resonance Spectrometer means this service is now available in-state. This provides an advantage to Northwest researchers and commercial producers both in testing turnaround and in the availability of the equipment and service for conducting customized research.

The principle of the test

The oil content test estimates the amount of oil that can be extracted from seeds using an industrial extraction method. Direct pressing extracts 90-92%, whereas solvent extractions remove 97-99% of oils contained in seeds.

specialtestingThe NMR technique measures the resonance energy absorbed by hydrogen atoms in the sample. Usually oil contents are expressed based on a specific moisture basis (e.g., 8.5%, 10%, etc.). Using the NMR in measuring oil content is referenced by ISO 10565:1998 Oilseeds.

Sample size and test period

Sample size is 5-10 grams for all analyses, not for each test, (i.e., for oil, protein and moisture).  We can calibrate the NMR for a smaller amount of seeds (i.e., 1-2 grams), if needed.   It takes 24 hours to complete the test from the time of receiving the sample. The NMR is a non-destructive method, so seeds can be returned if needed. Please enclose the sample in a moisture-proof (i.e. Ziplock) bag.

Research potential

We welcome inquiries from researchers worldwide. Please feel free to contact us to discuss your research needs.