When I began researching the ingredients for Twinkies, I naively thought that their raw materials were extracted from nuts, beans, fruit, seeds or leaves, and that they came from the United States. I was looking to link places with foods — along the lines of California wine or Maine lobster, but for thiamine mononitrate. It turned out that I was way off.

Although eight of the ingredients in the beloved little snack cake come from domestic corn and three from soybeans, there are others — including thiamine mononitrate — that come from petroleum. Chinese petroleum. Chinese refineries and Chinese factories. And there are other unexpected ingredients that are much harder to trace. So much for the great "All-American" snack food.

When you bite into a Twinkie, you are chewing on an international nexus of suppliers. Most of our processed foods — salad dressing, ice cream, meal-replacement drinks — are processed with foreign additives: essential ones, like B vitamins for fortifying flour and the preservative sorbic acid, as well as Malaysian or Indonesian palm oil products, European wheat gluten, Peruvian colorants, Chadian gums and Swiss niacin, made from Swiss water, Swiss air (nitrogen) and North Atlantic or Middle Eastern oil. It's a nice contrast to recall that Champagne comes only from Champagne, France.

Like many other industries, food additives have been off-shored. No major domestic vitamin or sorbic acid manufacturers remain in the U.S. Our last vitamin C plant closed in 2005 — in fact, it closed as I was speaking to an employee about a tour — and most of our artificial colors and flavors come from abroad as well. Our chemical industry is rapidly dismantling its expensive domestic plants and either forming joint ventures with Chinese companies or simply buying chemicals from them. This leads to lower food and pharmaceutical prices, but perhaps at the cost of quality control.

How can you have quality control when you don't even know where the ingredient is coming from? During my Twinkie research, I was particularly surprised that many American food additive "manufacturers" buy chemicals, especially vitamins, from distributors and do not know, or don't ask, where they come from. The distributors usually sing the same song, as they often buy from importers, and the importers buy from exporters who — no surprise — are often not able or willing to identify all of their sources.

Now that the tainted pet food scandal has made us more aware that many additives come from overseas, and China in particular — and that some unscrupulous or, at the very least, unprofessional Chinese manufacturers mix cheaper and poisonous adulterants into some food or pharmaceutical products — most of us would like to see some action. What can be done?

First, Chinese and any other foreign manufacturers should fall under both their home country's and the U.S. government's regulations and controls. This would take a concerted education effort in China, which has the challenge of teaching small, uneducated and very independent entrepreneurs the market value of meeting American standards.

Second, we need to increase U.S. inspection of imported foods and additives. This means increased personnel and budgets and a serious commitment from the government to a tight, professional program. The Food and Drug Administration should classify additive adulteration the same way the Agriculture Department classifies meat contamination: totally unacceptable. Congress would have to reverse the trend of underfunding the FDA.

Finally, as consumers, we can swallow hard and decide to pay just a little more for well-inspected processed food — or eat more local fruits, vegetables and whole grains and buy minimally processed and sustainably farmed foods.

Smart processed-food and pharmaceutical companies are scrambling to find guaranteed safe alternatives. But consumers must be prepared to pay a higher price for safe food — and to make informed choices about what ingredients go into our food and where they come from.

If you want to have your snack cake and eat it too, you have to remember: You are what you eat.

Steve Ettlinger is the author of the "Twinkie, Deconstructed." He wrote this commentary for the Los Angeles Times.