Saturday, January 26, 2008

New research into essential-oil extraction could help locals

Nguyen Thi Hong Ngoc from Quang Nam Province runs a profitable essential oil production business
An award-winning research group from Hanoi has used a method to extract essential oils from indigenous plants that could see locals reaping the benefits.

A group from the Ho Chi Minh City Institute of Chemistry Sciences grabbed headlines last May by successfully extracting essential oil from an Eaglewood tree using a specialized technique.

The “supercritical CO2 method” has been found in the past to slash the amount of time involved in extracting oil as compared to a traditional steam distillation technique.

Further, it opened the door to large-scale production of Eaglewood oil, highly valued on the international market.

The method consists of pumping pressurized or “supercritical” carbon dioxide (SCO2) into a chamber filled with plant matter.

SCO2, a gas with liquid properties, then acts as a solvent, pulling off the compounds responsible for the plant’s characteristic fragrances which are used to make perfume and aromatherapy products.

The SCO2 extraction process occurs in moderate temperatures (around 37 degrees Celsius) and allows the extracts to retain much of their natural fragrance and color.

The steam distillation technique on the other hand, involves high temperatures which can cause the extracts to lose many of their most valuable properties.

Unlike other chemicals used in the steam distillation process, SCO2 is also a non-toxic substance and thus ensures the safety of the final product.

For the last four years, three chemists from the Institute of Industrial Chemistry in Hanoi have also been experimenting with the supercritical CO2 method on an equally valuable source of essential oils.

Their illuminating research earned them first prize at the 2007 Youth Science and Technology Awards, jointly organized by the Vietnam Institute of Science and Technology and the Ho Chi Minh Communist Youth Union.

While the technique has been used for decades by chemists in other countries, the Hanoi researchers decided to apply the method to local vegetation with the ultimate goal of turning a seemingly useless plant into a source of income for local people.

The team conducted experiments on a type of plant called Vetiveria zizanioides L. Nash, or simply vetiver grass.

Widely cultivated in tropical regions around the world, the grass is a major source of essential oils for the aromatherapy and cosmetics industry.

“Vetiver grass is in fact as important as the Aquilaria family, which includes the Eaglewood tree, as a source for producers of perfume and aroma therapy products,” said Le Dang Quang, head of the research group.

Nguyen Mai Cuong, another research member, said that in addition to its valuable essential oil, vetiver grass with its long roots, can also prevent erosion.

Cuong was entrusted with collecting the grass along the Tien Hai coast in the northern province of Thai Binh.

“We chose this grass because we want to enhance its value and to encourage its cultivation for the industry, as well as for an environmental cause – erosion control,” said Cuong.

In the past, local vetiver growers chiefly cultivated the grass as a material to make incense with, since there was no efficient way to extract its essential oils.

“And incense, the making of which involves manual and simple techniques, isn’t a highly valued product on the market,” Quang added.

The two institutes’ projects, Quang said, show Vietnamese chemists’ growing interest in applying global scientific advances to local research.

Reported by Thuy Linh