Northern growers with a cotton-cereal rotation and consumers everywhere should welcome a genetic engineering breakthrough that doesn't add any ‘foreign’ genetic material but rather neatly turns off the gene that converts oleic acid in the plant into polyunsaturated fatty acids which, in the manufacturing process, produce unhealthy trans-fatty acids... read on.
Biotech researchers may have staked a claim for cotton growers in the future market for improved cooking oils by genetically modifying a plant to produce cottonseed with built-in cholesterol control.
The CSIRO achievement could allow cotton producers in future to capitalise on an expected increase in public demand for ‘healthier’ processed food.
The health price currently paid for the convenience of takeaway and ready-to-cook foods is that the oils used in their manufacture produce elevated levels of trans-fatty acids, which are just as bad for the body as saturated fats.
Scientists at CSIRO’s Plant Industry Division in Canberra have ‘switched off’ genes in cottonseed which normally convert oleic acid, a mono - unsaturated fatty acid, into polyunsaturated fatty acids.
Research leader Allan Green said that the ‘new’ oil could be used at high temperatures without hydrogenation, a chemical process necessary for stabilising the oil.
It is hydrogenation that produces the trans-fatty acids which raise the level o f ‘bad’ cholesterol in the blood, making it a risk factor for stroke and heart disease.
“The hydrogenation process converts the polyunsaturates back into mono-unsaturates, but we have prevented their formation in the first place,” said Qing Liu, the scientist who genetically modified the cotton.
“By turning off the gene that produces polyunsaturates, we have produced for the first time an inherently high-oleic cottonseed oil.”
In a related advance, Dr Liu has also tweaked the genes of the plant to alter the proportions of saturated fatty acids in its seed oil.
These saturated fatty acids provide the solid properties that allow the oil to be turned into margarine, but Dr Liu has demonstrated that a healthier balance is possible.
Dr Green points out that this kind of advance would be simply impossible through conventional breeding.
The CSIRO team believes it has beaten other major cotton producing regions, including Texas in the USA, which have also been pumping money into research to produce nutritionally improved forms of cooking oils, including canola.
Cottonseed is the sixth most-used vegetable oil worldwide, but in Australia it comes in third behind canola and palm oil.
“Australia spends some $50 million a year on imported palm oil but new labelling requirements are going to make the levels of saturates in this product more visible to the consumer,” Dr Green said.
“Food manufacturers will then be looking for healthier alternatives.”
A spokesperson for the Cotton Research and Development Corporation (CRDC) which supported the research hailed the value-adding potential, but stressed it was likely to be at least five years before a viable commercial plant could be produced.
Dr Green hopes the genetic modification, which involves re-inserting some of the plant’s own DNA and not inserting any foreign genes, will be entirely publicly acceptable.
Food Science Australia is due to begin testing the new cottonseed oil at the end of this year, with possible field trials of commercial varieties of the genetically modified plants to start in 2002.
Contact: Dr Allan Green 02 6246 5154