Symposium Highlights Potential Benefits of Citrus Compounds

By Kathryn Barry Stelljes
March 23, 1999

ANAHEIM, Calif., Mar. 23--Natural chemicals in citrus fruit could lead to tastier juice and to other benefits for farmers, food processors and health-conscious consumers, according to researchers presenting findings at a special symposium of the American Chemical Society here today.

In 1972, California chemist Shin Hasegawa at USDA’s Agricultural Research Service identified citrus compounds--called limonoid glucosides--that reduce the bitterness of the citrus juice. These compounds form naturally during ripening and can be extracted from seeds, pulp and other tissues left over after juice processing.

“Since then," he said, "we have isolated 17 of these compounds and developed methods for producing them on a commercial scale. We have also isolated the enzyme responsible for the production of limonoid glucosides." Hasegawa is based at ARS' Western Regional Research Center in Albany, Calif.

Hasegawa’s team has collaborated with researchers in several countries who are investigating potential health benefits and other uses for the compounds. As examples, university scientists have preliminary findings indicating the chemicals may have anti-cancer and cholesterol-lowering properties.

Diverse research on these citrus compounds will be presented today in a day-long symposium at the American Chemical Society’s 217th national meeting. “This is the first time all of the research on limonoids has been pulled together in one place,” said Hasegawa.

Scheduled topics for the symposium include:

• Biochemistry and characterization of citrus limonoids (presenters from ARS, Albany, Calif.; Nakamura Gakuen University, Japan);

• Anti-cancer activity of citrus limonoids (presenters from Baylor College of Dentistry, Dallas, Texas; University of Western Ontario, Canada; LKT Laboratories, Inc., St. Paul, Minn.; Kanazawa Medical University, Japan);

• Pest management using citrus limonoids (presenter from University of Maine, Orono);

• Extraction, recovery and processing of limonoid glucosides (presenters from Industrial Technology Center of Wakayama Prefecture, Japan; Shimadzu Corporation, Japan; Florida Department of Citrus, Lake Alfred, Fla.);

• Genetic mechanisms governing limonoid production in citrus (presenters from National Institute of Fruit Tree Science, Japan);

• Debittering citrus juice (presenter from ARS, Winter Haven, Fla.); and

• Limonoids as taxonomic markers for citrus species (presenter from ARS, Peoria, Ill.).

Scientific contact: Shin Hasegawa, or Gary Manners, Process Chemistry and Engineering Research Unit, ARS Western Regional Research Center, Albany, Calif., phone (510) 559-5819, fax (510) 559-5963, shinh@pw.usda.gov and gmann@pw.usda.gov.

During March 21-24, Hasegawa can be reached at the Hyatt Regency Alicante, phone (714) 750-1234, fax (714) 740-0465. During March 21-23, Manners will be at the West Coast, phone (714) 750-1811, fax (714) 971-3626.

For a backgrounder that provides more information on citrus limonoids, contact Kathryn Barry Stelljes, ARS Information Staff, phone (510) 559-6069, stelljes@asrr.arsusda.gov.

Paper abstracts and other details about the American Chemical Society meeting are available on the World Wide Web at http://www.acs.org/meetings/anaheim/welcome.htm.