BATTERED AND DOUSED IN BUBBLING OIL - why is fried chicken so delectable? Neither General Tso nor Colonel Sanders is quick to reveal the secret. Could it be ... MSG?

Today's leading Chinese American fast-food eateries, such as Panda Express, have a "No MSG" policy. KFC, meanwhile, continues to use MSG - monosodium glutamate - in everything from chicken to croutons. Yet many consumers associate only General Tso with this maligned ingrethent.

The Colonel has many compatriots in the MSG camp. If you've ever had the munchies for BBQ Lays, Doritos, Cheetos or flavored Pringles, you've heeded the call of MSG. In fact, the Food and Drug Administration lists MSG among substances "generally recognized as safe" and does not regulate its use.

Even so, the American public continues to associate MSG's purported dangers with Asian food in general, and with Chinese food in particular. But General Tso's chicken is as American as, well, anything fried in Kentucky, says Jennifer 8. Lee, the author of The Fortune Cookie Chronicles, which traces the history of Chinese food.

"We have this shared vocabulary around Chinese food," Lee says. This vocabulary includes fortune cookies and takeout boxes, which come in standard shapes that Lee notes are, ironically, "actually very American."

MSG is a chemical product, but high quantities of free glutamates also occur naturally in some foods. Free glutamates abound in vegetables such as mushrooms and tomatoes, and in condiments such as soy sauce, oyster sauce and fish sauce. And if you've heaped Parmesan cheese on your pasta, you've experienced the delights of free glutamates. It is no coincidence that Chinese and Italian foods, rich in the savory substance, are both among Americans' favorites. Really, where would we be as a nation without chow mein and spaghetti?

It is estimated that the average American consumes 550 mg of MSG per day. But MSG's use in food products and restaurants is nearly impossible to gaugeiwith accuracy. MSG's manufacturing process and the projected growth of its use are fiercely guarded trade secrets. Thanks to MSG's bad rep, food manufacturers even those known for making "natural" or "healthy" items - sneak in the ingrethent under such names as "autolyzed yeast extract" or "hydrolyzed protein."

Western scientists have traditionally identified four classes of taste: sweet, salty, sour and bitter. The savory flavor of L-glutamate. MSG's naturally occurring cousin, is now recognized as a fifth taste umami. Andrea Nguyen, Vietnamese cooking teacher and author of Into the Vietnamese Kitchen, says that the link between MSG and umami is underrecognized.

In fact, Nguyen savs. just as MSG can impart umami, "spaghetti and pizza are [equally] laden with umami" - but since many I Westerners have grown up eating these foods, they tend not to puzzle over them or ask, "Why does this pizza taste so good?" On the other hand, Nguyen says, the first time one eats Kung Pao chicken, the impulse is to say, "Mmm, that is so good. I wonder what the Chinese secret is."

Like fortune cookies, MSG's origins are not Chinese. As with many items that are symbolically linked to Chinese food, MSG has an obscure and convoluted history. Glutamate was first isolated in 1908 by Japanese chemist Kikunae lkeda, who was trained in Germany. Ikeda's research was influenced by the German aspiration to develop a low-cost, mass-producible form of nutrition.

Ikeda was particularly intrigued by a broth his wife made, called dashi, from a seaweed known as kombu. He took the ingrethent to his laboratory and discovered that kombu contains high quantities of free glutamates. After isolating the acid, lkeda used the word umami, colloquial Japanese for "tasty," to describe his discovery. In 1909, the Suzuki Chemical Company began marketing it under the brand name Ajinomoto, meaning "essence of taste."

Historical research by Jordan Sand, scholar of East Asian culture, revealed that from the mid-1 930s until 1941 , the United States purchased more Ajinomoto than any other country outside of Japan and Taiwan. US canned food manufacturers, particularly the Campbell Soup Co., generated much of the demand.

In 1947, MSG entered US supermarkets as Ac'cent (still sold today by B&G Foods). For the first time, Americans began cooking with MSG in their homes. "In the early 1950s, there were lots of ads for Ac'cent. It was seen as the wonder seasoning," says Thy Tran, executive director of the San Francisco Bay Area's Asian Culinary Forum. "If you look at [American] cookbooks of a certain era, MSG was added as an ingrethent."

Indeed. MSG consumption soared after World War II. During the US occupation of Japan, American military officers noticed that soldiers preferred Japanese rations to their own. "Flavojless rations can undermine morale as quickly as any other single factor in militar/ life," wrote Col. John D. Peterman of Quartermaster Food and Container Institute for the armed forces in 1 955. He soon arranged a symposium to discuss possible uses for MSG in US food industries.

MSG's public relations trouble began in 1968. In the same year that scientists warned of saccharin's carcinogenic effects, Robert Ho Man Kwok. a Chinese American doctor based in Maryland, rotei to The New England Journal of Medicine and reported that "for several years since I have been in this country, I have experienced a strange syndrome whenever I have eaten out in a Chinese restaurant. Especially one that served Northern Chinese food." Kwok's symptoms included: dizziness, numbness and palpitations. The journal titled the letter "Chinese Restaurant Syndrome," and a new medical condition was born.

Since Kwok's letter, MSG has undergone a barrage of laboratory and double-blind trials. According to a 1 995 report from an external panel to the FDA, otherwise-healthy individuals "may respond [adversely] to large doses" of MSG, showing symptoms such as headache, nausea, drowsiness and weakness, tingling in the face, temples, upper back, neck and arms; and a burning sensation in the back of the neck, forearms and chest.

The panel found, though, that "asthma is the only documented predisposing medical condition associated with adverse effects from ingestion of MSG." The panel also declared the term "Chinese Restaurant Syndrome" to be "pejorative."

Despite this, MedlinePlus, a medical encyclopedia published by the U.S. National Library of Medicine, continues to include "Chinese Restaurant Syndrome" as a diagnosable condition. Further, the relevant entry indicates that "a food additive called monosodium glutamate (MSG) has been implicated." Despite the disclaimer included as a side note - "but [MSG] has not been proven to be the substance that causes this condition" - Medline's first diagnostic question is: "Have you consumed Chinese food within the past two hours?"

MSG is maligned even among Asian Americans, many of whom believe that cheap, greasy Chinese food will induce lethargy or cottonmouth. Lee concedes: "My mom, who is Chinese, thinks it causes her headaches as well."

But, Lee adds, such myths stem partly from what she calls "exotic food syndrome" - that is, "if people eat different from us, they must be different from us. You see that [mentality] over and over again in the early history of Chinese immigration to the United States." This mentality has lent itself to outlandish myths, Lee says, leading Americans to believe that Chinese people routinely eat everything from dogs to cats to rats. As part of that context, "this idea of MSG [perpetuates] this fear of the exotic and the alien."

The very attitudes that necessitate today's "No MSG" signs, Lee says, have roots in the yellow-peril hysteria of the 19th century. The Chinese Exclusion Act of 1882 barred Chinese laborers from entering the United States for 10 years, and later legislation extended the ban until 1943 (when China became a US ally). In this era, Chinese labor was viewed as a threat not only to US jobs, but to Americans' quality of life. Food-related concerns were among the many justifications used to garner support for barring Chinese immigration.

In 1902, Samuel Gompers, founder of the American Federation of Labor, printed a pamphlet titled "Some Reasons for Chinese Exclusion: Meat vs. Rice. American Manhood against Asiatic Coolieism. Which Shall Survive?" He argued that Chinese subsistence on lowcost grain would, via adverse economic effects, undermine the living standards of American meat-eaters.

In that era, Chinese-owned businesses were eyed suspiciously as likely fronts for drug use. According to Tran, Chinese restaurants had to proclaim, "We are a real restaurant, not an opium den." A 1920s-era menu from the Grand View Garden in San Francisco's Chinatown - perhaps foreshadowing today's "No MSG" signs still proclaims that the "Wright Act is Strictly Enforced Here." (The "Wright Act" referred to federal opium bans supported by Hamilton Wright, the first US drug czar.)

Today, Chinese American restaurants are no longer linked with opium, but they have become synonymous with MSG, a substance perceived as an opiate of the food world.

Do Chinese American restaurants use MSG?

Yes, some do - but for good reasons, Nguyen says. "People tend to think that Asian food has to be cheap in order to be good," she says, and MSG allows cooks to make so-so ingrethents taste delicious for about the price of salt. As the public equates authenticity with low prices, mom and pop must cut costs to keep up with demand.

But this is changing: "There's much more awareness among Asian restaurateurs," Nguyen says, "and they're able to charge more, so they can use better ingrethents [and] they can pay their staff more - and, as a result, there is less manipulation of MSG, and the food tastes better overall."

For many years, the US food industry has let independent Chinese American restaurants take the flack for MSG, while MSG's usage by other entities goes largely unnoticed and uncontested. But competition for market share may be pushing manufacturers into cannibal mode, so to speak, with MSG serving as a focal point. In a 2008 ad campaign, for example, Campbell Soup called out Progresso for MSG use - despite the fact that Campbell uses MSG in its own product lines. Progresso responded by removing MSG from its soups.

But has Progresso really changed its ways - or, like many other brands, simply changed its labels? "Clean labeling" is a food industry term for using ingrethents that may be listed by more natural, or less maligned, names. The FDA considers "No MSG" or "No Added MSG" labels misleading if some ingrethents are free glutamate sources, such as yeast extract, autolyzed yeast extract or hydrolyzed vegetable protein. (MSG is a byproduct of hydrolyzed vegetable protein, and the substances are so similar that, according to Lee, the companies that produce them share the same lobbyist in Washington, DC.)

As US companies distance themselves from MSG, Ajinomoto has embarked on a costly, subtle campaign to promote naturally umami-rich foods without explicitly mentioning MSG. The company describes its goals in terms of corporate social responsibility, stating that, "In addition to spreading understanding of the umami seasoning Aji-no-moto, the Ajinomoto Group is helping to communicate the fact that umami is a universal taste, common to food cultures the world over." Its outreach includes the Umami Information Center, a nonprofit that publishes books and holds symposia. Featured symposium speakers include epicureans such as Thomas Keller of the famed The French Laundry restaurant in Napa County, CA.

This year, MSG celebrates its 100th birthday amid ongoing debate about its use in both Chinese and American food. For all the controversy, even food experts like Tran will not categorically condemn the ingrethent: "I'm not going to say it's good or bad. I dislike mislabeling in the same way I dislike prejudice and knee-jerk reactions to what [people] think is foreign. I think it's just a matter of trying to combat the great amount of ignorance around it."

Meanwhile, deep in the American belly and in the popular press, the battle rages on.

Writer Sita Kuratomi Bhaumik

Sita Kuratomi Bhaumik is a San Francisco Bay Area-based artist and writer.