Posted on: Wednesday, August 1, 2001

Soy, oyster sauce safety concerns lead two nations to institute bans

By Joan Namkoong
Advertiser Food Editor

Since summer 1999, e-mails and news articles have circulated questioning the safety of some brands of soy sauce and oyster sauce because of their levels of a compound that may be linked to cancer.

Several weeks ago, the Australia/New Zealand Food Authority banned 22 brands of soy sauce and oyster sauce after a warning by Britain's Food Standards Agency to avoid certain brands made in Thailand, China, Hong Kong and Taiwan.

The compound in question is 3-MCPD, a chemical that is not an additive but a result of processing, storage conditions or migration from certain packaging materials. It is not a compound unique to these sauces and occurs in a wide range of food products.

"It is a compound that is permissible" in foods, said Wai-Kit Nip, food scientist at the University of Hawai'i at Manoa. "The amount of the compound allowed in foods varies from country to country. The amount was over the limit in those countries that have banned it."

The allowable level that has been agreed upon and is to take effect in the European Union in April 2002 is 0.02 milligrams per kilogram, or 1 part to 500,000 parts by weight.

This is substantially lower than what is allowed in Canada, according to a U.S. Food and Drug Administration spokesperson in San Francisco.

The FDA has not set a standard level or an action level for this compound but is working with international standard-setting bodies and keeping an eye on the situation.

The sauces that were banned use a process called acid hydrolysis in which an acid, such as hydrochloric acid, is used to break down plant protein to release the amino acids or peptides in the product. This hydrolyzed vegetable protein is used in many products as a flavoring agent, boosting its "meaty" flavor.

Products that are naturally brewed and fermented are generally considered safe, because they do not undergo this process. These include Kikkoman and Yamasa soy sauces.

Lee Kum Kee, a manufacturer of Premium Oyster Sauce as well as Panda, Choy Sun and Kum Chun oyster sauces, is one of the companies that has come under scrutiny. According to a July 17 news release on its Web site, the British Food Standards Agency has acknowledged reports from Kee asserting that the company has reduced levels of 3-MCPD in its products.

Those who consume a primarily Asian diet and consume hydrolized soy and oyster sauces often and in significant amounts might have cause for concern, according to the FDA.

"It's all a matter of perspective," said Aurora Hodgson, extension specialist in food technology at the University of Hawai'i at Manoa. "Even natural foods have things that can harm you; processed foods are not alone" in that regard.