What Is Potassium Bromate (E924) And Why Many Countries Have Banned It In Baked Products?

Potassium bromate (E924) peaked in popularity in the 20th century for it improves the overall quality of baked products. It was until the 90’s when countries started banning the use of it in food products. Why is it banned? And are there any alternatives to potassium bromate during baking?

What Is Potassium Bromate (E924)?

Now that I have your attention, let’s define potassium bromate or KBrO₃ first. Potassium bromate, like the name suggests, is the bromate of potassium that comes in crystal or powder form. It does not have an odor and taste. Its E number is E924. The E numbers are numbers or codes that represent the food additives in the European Union. These E numbers are arranged according to their usage. Like for example E number 100 to 199 are food colorings. E number 900 to 999 are glazing agents, gases, and sweeteners. Although the European Union has banned KBrO₃ as a food additive.

Through a patent filed dated 1914, potassium bromate was first used in baked products. According to the patent, the application of haloic acids, oxidizing haloic salts, haloics salts of the alkali, and alkali earth metals during fermentation gives several benefits. These benefits include quality improvement of the baked product, increased product yield, less the amount of yeast needed, and shortened fermentation time. Bread that has been treated with KBrO₃ is unusually white, soft, and fluffy.

Today, potassium bromate is used in a wide variety of baked goods and other food products (beer and fish-paste products). But unlike before, there are not as many countries that permit it in food.

Why?

Potassium bromate, a carcinogenic potassium salt?

Like any other food additives, KBrO₃ has had its fair share of research regarding its safety. But in the 1970s, the Ministry of Health and Welfare of Japan commenced a series of carcinogenic testings on chemicals, including pesticides, medicines, and food additives. Among the chemicals selected for testing was KBrO₃ because of its mutagenicity and widespread use as food additive.

In 1978, a long-term bioassays of KBrO₃ found out that 2 years of oral administration of KBrO₃ is carcinogenic to rats and mice.

In 1982, a carcinogenic study involving 53 male and 53 female Fisher 344 rats was conducted. These rats were given KBrO₃ in water at concentrations of 0, 250 and 500 ml/liter for 110 weeks. But in week 60, 500 ml/liter was reduced to 400 ml/liter due to severe weight gain inhibition in male rats. Over the course of the study, immediate autopsy of the rats that died and survivors killed revealed that the incidence of tumors of the thyroid, kidney, and peritoneum was significantly higher in treated rats than in controls. The authors concluded that KBrO₃ oral administration was carcinogenic in Fisher 344 rats.

And in 2020, a study on the carcinogenic effect of potassium bromate on the tongue of adult male albino rats was performed. The study involved 60 adult male albino rats divided into three groups: control, experimental group I, and II. While the control group received distilled water, the experimental group I and II received 62 and 123 mg\kg KBrO₃, respectively daily for 2 and 4 months. The immunohistochemical results revealed a significant increase in the immunoreactivity of PCNA, and revealed dysplastic and carcinogenic changes in the experimental groups. The authors concluded that long-term administration has a carcinogenic effect, thereby a risk to public health.

What has become of the potassium bromate market?

Following the series of Japanese carcinogenic studies, the International Agency for Research on Cancer classified KBrO₃ a category 2B carcinogen (possibly human carcinogenic) in 1999. With that having said, we cannot really blame consumers if they avoid it. Bread is a daily food, right?

Unsurprisingly, the market for KBrO₃ is experiencing a sluggish growth, according to Transparency Market Research. The main reason for this is the shrinking market for the food additive. In fact, a lot of countries have banned the use of it in food products since 1990. The European Union does not allow KBrO₃ in food since 1992, since 1994 in the Philippines and Canada. Other countries that have blacklisted the additive include Argentina, Korea, Peru, Sri Lanka, Nigeria, India and China. The latter two were the ones of the last to prohibit KBrO₃ in 2005 and 2016, respectively.

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The United States, on the other hand, still allows potassium bromate in baked products in permissible limits. But despite the green light, the flour improver has consistently dropped in popularity as consumer awareness grows. One of the reasons for this is that the US Food and Drug Administration (FDA) has been urging bakeries and manufacturers to no longer use KBrO₃ in their products since the early 1990s. The FDA allows up to 75 ppm when added to whole wheat flour, and up to 50 ppm in white flour.

Checking of potassium bromate in flour and food

KBrO₃ remains a legal ingredient in flour and baked products in the United States. However, it is not surprising to know that more Americans prefer KBrO₃-free products. The American Bakers Association once said that most of their members have already stopped using bromated flour. Even so, it does not take away the fact that KBrO₃-treated baked goods are still in the market. In fact, the Environmental Working Group (EWG) reported that at least 86 baked and other food products include KBrO₃ as an ingredient. Including in the list are popular brands such as Weis Kaiser rolls, Hormel Foods breakfast sandwiches, and Goya turnover pastry dough. But manufacturers and bakeries are not to blame here— KBrO₃ is still allowed in the United States.

If you want to steer clear from baked products with bromated flour, make it a habit to read the label, as always. A product has been treated with KBrO₃ if the ingredients list includes the words “potassium bromate” and/or “bromated flour”. Another way to ensure safety is by purchasing products that say the words “bromate-free” on the label

Reading the label before purchase will help you make informed decisions.

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In the state of California, the local law requires manufacturers of baked products treated with KBrO to have a warning sign on the label, just like the graphic below.

potassium bromate to bear a warning sign on the packaging.

Alternatives to potassium bromate

KBrO₃ is very effective as a flour enhancer and dough conditioner. If not only for the possible adverse health effects, the demand for it would be off the charts. However, for bakers, there are other alternative ingredients that serve the same purpose.

In terms of bromate replacers, ascorbic acid (vitamin C) is a healthier alternative and is the most commonly used, even in large scale baking, Ascorbic acid can be purchased in synthetic or natural form. The FDA allows up to 200 ppm of ascorbic acid based on flour weight if used as flour improver and dough conditioner.

Another oxidizer is azodicarbonamide (ADA), which was patented in 1959. ADA can be applied 10 to 20 mg/kg of flour. In terms of speed, ADA is one of the fastest, reacting within a few minutes right after mixing of flour and water. However, it does not react on dry flour. Popular food chains including Wendy’s, McDonald’s and Burger King use ADA in their sandwich breads and burger buns.

The amino acids cysteine is a popular antioxidant. This amino acid also conditions the dough, increases its elasticity to help it rise during baking.