Oil palm trunk fiber shows functional food potential

Oil palm trunk fiber has shown potential as a functional food ingredient and may help manage and lower the risk of diabetes, colon cancer, heart disease and obesity, according to preliminary research results presented at the Experimental Biology conference in San Diego this week, reports Jess Halliday.

Extracted from the trunk of the oil palm, a tree indigenous to West Africa and cultivated in Malaysia and Indonesia, oil palm trunk fiber has been shown to be an excellent antioxidant and is thought to promote glucose metabolism and manage healthy cholesterol levels in sufferers of type 2 diabetes.

To establish its potential as a source of dietary fiber, Dr Alex Schauss, director of natural and medicinal products research for the American Institute for Biosocial and Medical Research in Tacoma, Washington, fed oil palm trunk fiber to rats and measured the fecal bulking, water retention capacity, colonic water load and dry matter, which gives an indication of soluble and insoluble fiber content.

The results were compared with those produced by three other fibers under the same conditions: American Association of Cereal Chemists' wheat bran, Danisco's Fibrex and, as an international reference, IHWB wheat.

"We were really surprised by the results. In every variable and parameter, oil palm trunk fiber proved superior to all other sources," Schauss told NutraIngredients-USA.com.

Most surprising, however, were the results of the antioxidant assays. Oil palm trunk fiber was found to have an unusually high ORAC (oxygen radical absorbance capacity) value - 93, compared with 94 for cranberries, 92.6 for wild blueberries and 49 for raspberries.

A randomized, double blind, placebo controlled study is also currently underway and although the full results will not be available until June, the indications are that it could have the ability to promote glucose metabolism and manage healthy cholesterol levels.

Schauss explained that oil palm trunk fiber is very light and can absorb a lot of water without congealing. It can withstand extremes of temperature and moisture conditions during food processing, and could have a wide range of applications in foods where fiber might usually be added, such as yogurts, breads, pastries and other products using durum wheat.

Production methods used in Malaysia also mean it can be certified organic - a status verified by Schauss by testing for 38 different pesticides and herbicides.

Although it is not yet available in the US, a cereal made using oil palm trunk fiber has been introduced in Malaysia through Sukhe International, the Selangor Daru Ehsan-based company which extracts the trunk fiber using a patented process and is funding ongoing research.

The success of oil palm trunk fiber in the functional foods market would mean Malaysia can generate revenue out of a waste product that has, until now, proved problematic.

Malaysia produces 50 percent of the world's palm oil and has 3 million hectares of the trees under cultivation. Every year, 9 million trees become nascent and must be cut down, with saplings planted in their stead.

However anti-pollution laws introduced in the 1990s mean that the 7 million tones of dead wood, which is of little use for furniture making, cannot be burned. When left on the ground it has been found to make the soil infertile.

The Malaysian government first started looking into uses for the wood in the 1980s, when it asked a Japanese scientist to investigate its possible use for animal feed. He established that it could be used as a nutritional source, but it was not until 1996 until the patented production process, which makes it palatable for humans, was developed, sparking Schauss' research.

A case history for the fiber has already been established in Malaysia, involving 400 human subjects suffering from constipation, over several years. According to Schauss, 100 percent of participants reported an improvement in bowel function improvement.

Schauss expects the full complement of studies, which also include toxicology and dosage investigations, to be completed by the end of 2004, after which it will be submitted for self-affirmed GRAS status and registered with the FDA as a new dietary ingredient.

Once the regulatory obligations have been fulfilled, oil palm trunk fiber could reach the market as a functional food and dietary supplement ingredient as early as next spring.