Chewing the fat
From the September 2009 edition of Agriculture Today.
Hear Farrer Oration
The World Congress on Oils and Fats in Sydney from September 27 to 30 will coincide with the 28th Congress of the International Society for Fat Research. Dr Mailer will receive the Farrer Memorial Medal at the Congress on Monday, September 28, and deliver the 2009 Farrer Oration. There is an open invitation to everyone to hear his address.
Such is his faith in the excellence of Aussie edible oils, this man would have you eat liquid oil on bread.
"It makes more sense and solid spreads are hardly necessary," says principal research scientist, Dr Rod Mailer.
Knowledge of health and nutrition feeds his preference and his track record gets the ears of oil aficionados, worldwide.
What Dr Mailer does like to spread is word that virtually all of the olive oil produced in Australia is extra virgin, with no facilities for solvent extraction of pomace oil, in contrast to the large amounts of refined oil produced in Europe.
Not looking to start a taste war, or a cliché-fest on whether oils are oils, the winner of this years Farrer Memorial Medal is about to chair an international gathering of the worlds oils and fats scientific community in Sydney.
"Fats and oils are an important and necessary part of our diet but perhaps the most asked question about them is which oil is the best for health?" Dr Mailer said.
The question will consume delegates at the World Congress on Oils and Fats, to take place on September 27 to 30, along with the 28th Congress of the International Society for Fat Research, of which Dr Mailer is the president.
Dr Mailer is a principal research scientist with the Primary Industries division of Industry and Investment NSW and the EH Graham Centre at Wagga Wagga Agricultural Institute.
He says developments in oils and fats research and technology are critical to many industries including agriculture, health and nutrition, food and food service, biotechnology and the olive and canola oil industries.
A deep frying symposium and short courses on lipid oxidation, antioxidants and olive oil will be additional drawcards to the program.
"Food manufacturers, chefs and consumers will find the short course on deep frying particularly valuable," Dr Mailer said.
"The world of fast food, particularly, can better understand the types of oils to use for frying, how long they can be used and the health and nutritional benefits for consumers."
Since 2001, Australian olive oil production has grown 24-fold and exports have grown 6.5-fold, according to the Rural Industries Research and Development Corporation.
Dr Mailer's studies on olive oil quality, harvest timing, irrigation and storage have earned him international recognition for his major contribution to the development of the Australian olive industry and contributed to him winning the 2009 Farrer Memorial Medal.
Dr Mailer expects the Australian olive oil industry to increase substantially over the next few years.
With its consistent production of high quality oil, Australia is already the envy of many traditional olive oil producing countries.
Issues of production, processing, quality and varieties are up for discussion at the forthcoming World Congress.
"The Congress will provide vital input for shaping the industrys future in Australia," Dr Mailer said.
The chemical composition of olive oil, processing and storage, factors that impact on quality and olive oil variability will all be addressed at the four day congress.
A short course on olive oil will cover methods of determining quality, origin and authenticity of olive oil, the nutritional difference between Extra Virgin and refined olive oils, and trade and global market dynamics.
When anyone asks "how much fat is in oil?" these folk will simultaneously hit their buzzers with 100 per cent consensus that fats and oils are both fat.
As to which oil is the best for health, Dr Mailer says perhaps the most important factors are melting point and oxidative stability at high temperature.
"The more saturated the fat is the more stable it is when heated," he said.
"Therefore, palm oil, cottonseed oil and tallow are used for high temperature application such as deep frying."
Polyunsaturated oils such as canola oil are susceptible to oxidation and rancidity when heated, so they are used more for salad dressings and cold applications.
Fish oil, which provides some of the most important fatty acids for health, including long chain omega-3 polyunsaturated fatty acids, EPA and DHA are highly susceptible to oxidation and can quickly become rancid.
Almost all the oils are extracted from the original grain in processing plants and cleaned up or refined before being sold to the consumer, Dr Mailer said.
Olive oil is unique in that it is more commonly sold without processing.
"Virgin describes oil which has not been processed, sometimes called cold extraction although this term is not totally correct," he said.
Fruit is crushed and the oil removed, filtered and bottled without any chemical process.
Some olive oil is processed and may be referred to as "olive oil" or "pure olive oil".
"These terms are misleading as they dont indicate that the oil has been processed," Dr Mailer said.
"Extra virgin olive oil is the premium quality product, extracted without any chemical process, maintaining high quality to ensure oil components including antioxidants and fruity flavour, are intact."
Pomace olive oil is the lowest quality, being that fraction left in waste material during processing.
Pomace oil is extracted with solvents, then chemically treated to make it fit for human consumption.
Back to Dr Mailer's suggestion about spreading liquid oil on bread or toast in preference to solid fats: he points out that some fatty acids are essential for health and some fat soluble vitamins are only found in dietary fat.
"Oil and fat are made up of fatty acids - long chains of carbon atoms connected by chemical bonds," he said.
"Mostly there is a single bond between each carbon - called a saturated bond.
"Sometimes they may be double bonds - unsaturated.
"So, oil with a large amount of fatty acids and no double bonds (butter, palm oil, tallow) are saturated fats."
Oils with predominantly fatty acids and a one double bond (olive oil, canola oil) are monounsaturated oils.
If the majority of fatty acids contain two or more double bonds (sunflower, soybean) they are referred to as polyunsaturated.
The only difference between fat and oil is the melting point: oils melt to a liquid at room temperature.
When butter was considered too high in saturated fat, substituting vegetable oils in margarine replaced saturated with polyunsaturated fat.
However, Dr Mailer says the only way to produce spreadable fat from liquid vegetable oil to satisfy consumers desires for solid fats to put on bread or toast is to either blend it with a hard fat such as palm oil, or chemically treat it to change the fatty acids and increase the melting point.
Both of these processes have some disadvantages.
"Blending with palm oil significantly increases the saturated fat level and in doing this brings back the same issues that exist in eating butter," he said.
"The other alternative of treating the oil by a process known as hydrogenation changes the shape of some of the fatty acids to form trans-fatty acids.
Nutritionists now consider trans fatty acids to be the most undesirable of the fatty acids and alternative methods are now being used to solidify vegetable oil for spreads.
Industry and Investment NSW maintains the Australian Oils Research Laboratory at Wagga Wagga, devoted to the analysis of fats and oils.
The laboratory is accredited by the International Olive Council, Madrid, to test olive oil and ensure it meets world class standards.
The laboratory also tests all other vegetable oils both for research and commercial purposes.
Visit www.isfsydney2009.com for information on the Congress and registration.
Contact Rod Mailer, Wagga Wagga, 02) 6938 1818, rod.mailer@industry.nsw.gov.au
- Ron Aggs
Cereal spotlight also at Wagga
While the World Congress on Oils and Fats is taking place in Sydney, another significant symposium will coincide at Wagga Wagga.
For nearly 60 years, the annual Australian Cereal Chemistry Conference has attracted speakers and delegates from throughout Australasia, the US and Europe.
This years 59th conference will be held at the Charles Sturt University (CSU) Convention Centre from September 27 to 30.
Issues to be covered in the three day program will include the evolving role of cereals in health and diet, new technological tools and applications, identification of the genetic basis to desired quality traits, climate change and environmental impacts on grain quality, new grain marketing and classification arrangements, and the domestic and global outlook for the future of the food grains industry in Australia.
The conference will be relevant to all sectors of the grains industry - marketers, breeders and growers, processors, researchers, product developers and service providers.
Primary Industries staff of Industry and Investment NSW based at Wagga Wagga and Yanco are working with conference chairman, Dr Chris Blanchard, of CSU and the EH Graham Centre, to organise and run the event.
It is the first time in nearly two decades the conference, with the theme "Quality Science for the Country", has returned to regional Australia, this time to a location with some symbolic history.
Extensive wheat variety trials in the Wagga area began in the 1890s with the work of plant breeder, William Farrer, and plant pathologist, Nathan Cobb.
The site of their work eventually grew into the Wagga Wagga Agricultural Institute, with CSU evolving in parallel.
Conference keynote speaker, Professor George Fahey, of Illinois University, will speak on dietary fibres, wholegrains and health; Dr Grant Campbell, Manchester University, UK, will present papers on technological innovations in flour milling and on the role of cereal crops in biorefineries, and Dr Ravi Chibbar, University of Saskatchewan, Canada, will speak on the genetic modification of cereal grain carbohydrates for food, feed, fibre and improved human health.
Contact the committee at Cereal.Chem09@industry.nsw.gov.au, or visit the conference website at www.csu.edu.au/faculty/science/biomed/cereal-chem
