The development of hemp plants with drastically increased oleic acid content has resulted in a cooking oil that is similar to olive oil in terms of fatty acid content, but which has a much longer shelf life as well as greater heat tolerance and potentially more industrial applications, according to a release announcing the findings.

Researchers at the University of York said that high oleic acid content in the plants is a major step forward towards hemp becoming a commercially attractive crop for cereal farmers. The research was published in Plant Biotechnology Journal.

Scientists selected hemp plants lacking the active form of an enzyme involved in making polyunsaturated fatty acids. Instead, these plants accumulated higher levels of the monounsaturated oleic acid. Then, using conventional plant breeding techniques, they developed a breed of the plants into a "High Oleic Hemp" line.

"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 mono-unsaturated/low poly-unsaturated 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," writes the statement.

Declining yields of rapeseed and increased pests and disease attacks means UK farmers need another break crop to maintain sustainability of their fields. 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. 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," said Ian Graham, professor from the Centre for Novel Agricultural Products at York.