Scientists report the development of hemp plants with fatty acid content similar to that of olive oil, as well as a longer shelf life and greater heat tolerance.
The researchers say that high oleic acid varieties are a major step towards developing hemp as a commercially attractive break crop for cereal farmers. Their findings appear in Plant Biotechnology Journal.
Using fast-track molecular plant breeding, the scientists selected hemp plants lacking the active form of an enzyme involved in making polyunsaturated fatty acids. These plants made less polyunsaturated fatty acids and instead accumulated higher levels of the monounsaturated oleic acid.
The research team used conventional plant breeding techniques to develop the plants into a “high oleic hemp” line. A Yorkshire field trial demonstrated the higher oleic acid content.
Oil from the new line was almost 80 percent oleic acid, compared with typical values of less than 10 percent in the standard hemp line. This high monounsaturated/low polyunsaturated fatty acid profile increases the oil’s thermal stability and oil from the new line was shown to have around five times the stability of standard hemp oil.
This not only makes the oil more valuable as a cooking oil but also increases its usefulness for high temperature industrial processes.
As oilseed rape faces declining yields and increasing attacks from pest and disease, farming in the UK needs another break crop to ensure the sustainability of its agriculture and maintain cereal yields. An improved hemp crop, yielding high quality oil, would provide an excellent alternative.
Hemp is a low-input crop and is also dual-purpose, with the straw being used as a fiber (for bedding, composites, and textiles), for biomass and as a source of high value waxes and secondary metabolites.
“The new line represents a major improvement in hemp as an oil crop,” says Professor Ian Graham in the University of York biology department. “Similar developments in soybean and oilseed rape have opened up new markets for these crops, due to the perceived healthiness and increased stability of their oil.”
In 2014, field trials of the new “high oleic hemp” are being rolled out across Europe in order to establish agronomic performance and yield under a range of environmental conditions in advance of launching a commercial crop.
Source: University of York