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HONOLULU, Dec. 16 - A team of Japanese scientists has found that inducing brown rice to germinate - by soaking it for several hours before it is cooked - enhances its already high nutritional value.
The findings were presented here today during the 2000 International Chemical Congress of Pacific Basin Societies. The weeklong scientific meeting, held once every five years, is hosted by the American Chemical Society, in conjunction with its counterparts in Australia, Canada, Japan and New Zealand.
Germinated rice contains much more fiber than conventional brown rice, three times the amount of the essential amino acid lysine, and ten times the amount of gamma-aminobutyric acid (GABA), another amino acid known to improve kidney function.
The researchers also found that brown rice sprouts - tiny buds less than a millimeter tall (1/16 of an inch) - contain a potent inhibitor of an enzyme called protylendopetidase, which is implicated in Alzheimer's disease.
The researchers determined that germination activates enzymes that liberate additional nutrients. "The birth of a sprout activates dormant enzymes in the brown rice all at once to supply the best nutrition to the growing sprout," explained Hiroshi Kayahara, Ph.D., the lead investigator on the project, and a biochemist from Shinshu University in Nagano, Japan.
Rice, whether brown or white, is a major part of most Asian diets, often eaten with nearly every meal. That adds up to 300-400 pounds per person each year, according to the Asia Rice Foundation. Americans eat much less rice, about 15 pounds per person each year. Europeans eat even less rice, little more than six pounds per person each year.
To make the rice sprout, the researchers soaked it in water at 32 degrees C (about 90 degrees F) for 22 hours. The outer bran layer softened and absorbed water easily, making the rice easier to cook. Cooked sprouted rice has a sweet flavor, the researchers report, because the liberated enzymes break down some of the sugar and protein in the grain.
White rice will not germinate using this process, notes Kayahara.
China, India and Indonesia - home to nearly half of the world's people - are the world leaders in rice production. Expanding populations throughout Asia will require rice production to increase by about a third over the next 20 years, according to the Rice Foundation.
More than 8,000 research papers will be presented during this year's International Chemical Congress, which is sponsored jointly by the American Chemical Society, the Chemical Society of Japan, the Canadian Society of Chemistry, the Royal Australian Chemical Institute, and the New Zealand Institute of Chemistry.
The paper on this research, AGRO 155, will be presented at 3:45 p.m., Saturday, Dec. 16, at the Hilton Hawaiian Village, Iolani Suite III/IV, 2nd floor, Tapa Conference Center, during the symposium, "Quality of Fresh and Processed Food."
Hiroshi Kayahara is a professor in the department of bioscience and biotechnology at Shinshu University in Nagano, Japan. His co-authors on the study are K. Tsukahara and T. Tatai.