Oilseed Composition and Extraction Methods

Oilseeds represent a vital source of lipids, proteins, micronutrients and bioactive phytochemicals that underpin global food, feed and industrial sectors. Their lipid fraction is dominated by triacylglycerols composed of saturated, monounsaturated and polyunsaturated fatty acids, along with minor but functionally significant constituents such as tocopherols, phytosterols, phenolics and phospholipids. Protein bodies provide essential amino acids, while ash and carbohydrate residues carry minerals, fibre and antinutritional factors. The balance of these components varies across species—crops such as soybean, rapeseed, sunflower and emerging seeds like camelina and chia display distinct fatty acid profiles and antioxidant contents that determine nutritional value, oxidative stability and functional applications.

Extraction approaches shape yield, composition and sustainability. Traditional mechanical pressing (cold pressing, expeller pressing) conserves heat-sensitive compounds but may leave residual oil. Solvent extraction (most commonly hexane) achieves high recovery yet raises environmental and safety concerns. In response, green technologies have gained traction, including supercritical CO₂, ultrasound-assisted, microwave-assisted and enzymatic methods, which can enhance selectivity, reduce energy input and preserve minor bioactives. Post-extraction refining steps—degumming, neutralisation, bleaching and deodorisation—further refine quality but may diminish beneficial compounds. Optimising extraction parameters is critical to deliver oils tailored for edible, cosmetic, pharmaceutical and biofuel uses, aligning resource efficiency with nutritional and environmental goals.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Oilseed Composition and Extraction Methods publication trend

The graph below shows the total number of articles in oilseed composition and extraction methods across all publications each year (not limited to Nature Index journals).

Technical terms

Triacylglycerol: The main storage form of fatty acids in oils, consisting of three fatty acid chains esterified to a glycerol backbone.

Cold pressing: A mechanical extraction method performed at low temperature to preserve heat-sensitive compounds.

Soxhlet extraction: A continuous solvent extraction technique that repeatedly washes solid material with a boiling solvent to maximise oil yield.

Supercritical CO₂ extraction: A green method using carbon dioxide above its critical temperature and pressure to dissolve and recover lipids without organic solvents.

Ultrasound-assisted extraction: The use of ultrasonic waves to disrupt cellular matrices and enhance mass transfer of oil into solvent or carrier medium.

Polyunsaturated fatty acids (PUFAs): Fatty acids with two or more double bonds, valued for health benefits but prone to oxidative degradation.

Tocopherols: A class of vitamin E compounds acting as natural antioxidants in oils and biological systems.

Fourier transform infrared (FTIR) spectroscopy: An analytical technique that measures molecular vibrations to identify functional groups and monitor chemical changes.

References

1. The Chemical Composition and Health-Promoting Benefits of Vegetable Oils—A Review. Molecules (2023).
2. An Overview on Traditional vs. Green Technology of Extraction Methods for Producing High Quality Walnut Oil. Agronomy (2022).
3. Influence of the Extraction Method on the Quality and Chemical Composition of Walnut (Juglans regia L.) Oil. Molecules (2022).
4. A Study of Degradation in Vegetable Oils by Exposure to Sunlight Using Fourier Transform Infrared Spectroscopy. Materials Sciences and Applications (2020).
5. Herbal Additives Substantially Modify Antioxidant Properties and Tocopherol Content of Cold-Pressed Oils. Antioxidants (2021).