Researchers at Michigan State University have engineered oilseed crops to produce high hanklevels of acetyl-triacylglycerol (acetyl-TAG). This unique plant oil has enhanced low-temperature properties, lower viscosity, lower calories and additional attractive qualities. Acetyl-TAG has a wide range of food and non-food applications as emulsifier, plasticizer, solvent, and drop-in biofuel. The oil has been produced in field trials in the US and Canada.
Currently produced plant oils for commercial use are triacylglycerols (TAG) that have three fatty acids attached to a glycerol backbone. The physical and nutritional properties and the uses of plant oils are determined by the structure of the three fatty acids. Acetyl-TAG differs from all current commercial plant oils by having one of the three fatty acids replaced by a 2-carbon acetyl group. This change in the oil structure confers a number of unique and useful properties to the oil. The freezing point, pour point, cloud point and viscosity are all substantially reduced thus making the oil ideal for several low-temperature applications such as lubrication, hydraulic fluids, dielectric fluids, etc.
Acetyl-TAG is also similar in structure to vegetable oil based plasticizers and emulsifiers that currently are produced semi-synthetically using chemical modifications. This technology allows biological synthesis of such structures directly in the seed and therefore can reduce the production costs of the end product. An additional advantage of acetyl-TAG is that by having two, rather than three long-chain fatty acids favors the formation of more flexible linear polymers compared to cross-linked polymers produced from conventional vegetable oils.
Camelina producing acetyl-TAG was engineered by introducing a specialized acetyl-transferase gene isolated from the seeds of Euonymus alatus (Burning bush). Multiple field trials have shown that the special acetyl-TAG oil can be produced in high yield and extracted and processed by standard industry protocols. This technology has the potential to be used in a large variety of oil crops such as canola, soybean etc.
- New biofuel: Acetyl-triacylglycerols are a new renewable fuel-oil that would be extracted from oil-seed crops and provide improved properties for uses as fuels without the need of esterification. Acetyl-triacylglycerols have lower viscosity and may also be used directly as a fuel (without esterification) for some applications.
- New low-calorie food ingredient with lower cost: The lower calorie content and better (reduced fat storage) bodily fate of ac-TAGs compared to equivalent conventional TAGs provides an opportunity to produce “natural plant oils,” and thus foods with lower calorie content, without the need to chemically modify oils.
- New polymer substrate: Substitution of acetyl-TAGs for conventional TAGs will provide opportunities to produce novel polymers with new properties.
This technology can provide a new biofuel with improved properties at lower production cost compared to existing biodiesel products. Also, ac-TAGs can provide new polymers with new properties and a lower calorie content food ingredient compared to conventional TAG oils.
US 7,429,473 (issued September 30, 2008)
Michael Pollard, John Ohlrogge, Timothy Durrett
Learn more about the Great Lakes Bioenergy Research Center (GLBRC) at MSU