Dear EarthTalk: Why do food manufacturers add potentially carcinogenic potassium bromate to the flour of many packaged baked goods we consume? What are the risks and how can we minimize them?
Annie C., Poulsbo, Wash.
It may sound strange, but many food manufacturers around the world still choose to improve the quality and appearance of their baked goods by adding the carcinogenic compound known as potassium bromate (KBrO3) to their plain flour.
Potassium bromate, a “potential human carcinogen” according to the International Agency for Research on Cancer, is often used as an oxidizing agent in the production of baked goods such as bread or pizza.
For a baked good to achieve that chewy, lifted look and texture, it must first be oxidized. In the past, the dough was kneaded several times by a baker, then left in the open air to oxidize naturally; a process that can take days or even weeks. Potassium bromate shortens this process by directly and more powerfully strengthening the bonds between gluten (the building blocks of any baked product), resulting in a more effective and beautiful baked product.
But is the possibility of cancer worth it? Potassium bromate is unfortunately an excellent source of free radicals (unstable atoms) called reactive oxygen species (ROS), the kind that cause mutations in our DNA. These mutations can in some cases accumulate, producing cancers of the thyroid, liver and kidneys.
In 1982, Japanese researchers were the first to publish a series of articles indicating that potassium bromate caused these different types of cancer in rats. Soon after, many countries banned its use (including the European Union, Argentina, Brazil, Canada, Nigeria, South Korea, and Peru, among others). The FDA, however, felt that the United States did not need to ban potassium bromate because levels in most baked goods sold were unlikely to exceed 20 parts per million (ppm), an amount deemed safe for human consumption.
Before heading to the nearest poison control center, remember that it is the amount of potassium bromate in the final product that ultimately determines its carcinogenic potential, not its mere presence. According to the FDA, 50 ppm (parts per million) is the upper limit for its use in brominated flour. As for its use in bread, 75 ppm is considered the limit for safe human consumption.
If you are a hobbyist who likes to bake your own bread or other similar products, it should be noted that if your product does not reach a high enough temperature, or is not baked long enough, it may contain residual amounts of potassium. bromate. Your best option for baking carcinogen-free items is to use non-brominated flour, although the process is a little different. More mixing is required (because there is less oxidative potential), as well as setting a lower initial temperature (due to the temperature increase due to mixing).
As for those hoping to purchase bromine-free baked goods, of course the law requires that all ingredients be listed on the package. If you are lucky enough to live in California, a warning label indicating carcinogenic ingredients should be visible on the packaging. Keep an eye out for “potassium bromate” or “brominated flour” – and if you see either ingredient, do yourself a favor and bring it back.