The Bane of Snack Foods: Acrylamide
By Steve Campbell
While discussions about acrylamide and just how much of a health threat it actually poses to the population at large continue, what is indisputable is the fact that this food contaminant is pervasive in the food supply, found in literally thousands of food and beverage products consumed every day worldwide. And while it may not yet be widely recognized by the public, almost every person on the planet who eats cooked or manufactured food ingests acrylamide on a regular basis.
Clearly carcinogenic in animal toxicity tests, acrylamide is classified by the World Health Organization (WHO) to be “probably carcinogenic” to humans. It is also known to be mutagenic, neurotoxic and genotoxic. Moreover, studies show that it presents a disproportionate health risk to babies and children. For example, the acrylamide in foods consumed by pregnant women may cause a reduction in their baby’s birth weight and head circumference—key indicators of a child’s future health and intelligence.[2,3] According to Health Canada, because of their smaller bodies and the types of foods they consume, young children typically ingest each day twice as much acrylamide (per kilogram of body weight) as adults.
Plainly then, acrylamide presents a significant quality, health and safety challenge for much of the food industry, and a problem many food manufacturers would like to resolve—or at least mitigate to an acceptable degree. The good news: A reasonable solution—one that is efficacious, minimally disruptive and non-genetically modified (GM)/clean label—is close at hand.
An Issue since 2002
Dietary acrylamide exposure has been a concern since 2002, the year Swedish scientists first confirmed the carcinogenic chemical’s presence in many commonly consumed foods.3 That discovery was originally triggered by the unsafeguarded use of acrylamide in a 1997 Swedish railway tunnel construction project that poisoned rivers, killing local cows and fish. In addition, 19 of the tunnel workers exposed to the acrylamide suffered damage to their peripheral nervous systems, resulting in headaches, prickling sensations in their limbs, dizziness and nausea.
Subsequently, the discovery in food was uncovered when Swedish health authorities decided to compare the high levels of acrylamide found in those workers with those of members of a control group of unexposed individuals. Although the workers had been subjected to extremely high levels not normally found in food, the comparison also found high levels of acrylamide in the control group. A subsequent follow-up study released on April 24, 2002, revealed a troubling and widespread presence of acrylamide in many commonly consumed foods. Today, similar to back in 2002, the acrylamide levels found in various food products can be up to 500 times higher than the previously established WHO and U.S. Environmental Protection Agency (EPA) allowable limit in drinking water of 0.5 parts per billion (ppb).
Of note, acrylamide is not added to food but instead forms when carbohydrate-based food items containing a naturally occurring amino acid, asparagine, interact with reducing sugars through frying, baking or toasting above 120 °C. Since 2002, governmental food safety agencies from around the world have confirmed and monitored acrylamide’s presence in many different foods, including processed potato products (french fries, chips) and other foods (biscuits, crackers, bread, toast, crisp and soft breads, fried dough sticks, rice and coffee).
European Union Moving to Establish Legal Limits for Acrylamide in Food
Acrylamide continues to be an important issue for health regulatory bodies worldwide, including the European Food Safety Agency (EFSA) and Health Canada. Other countries (Hong Kong, Japan, etc.) have issued reports over the last 12–24 months emphasizing ways for food manufacturers to lower the acrylamide content in their products to ALARA (as low as reasonably achievable) levels. In the U.S. last year, the U.S. Food and Drug Administration (FDA) issued voluntary guidelines for U.S.-based manufacturers. In California, acrylamide is already subject to labeling regulations under the state’s Proposition 65 carcinogen law, and a private lawsuit is currently underway against shops and chains that serve coffee containing acrylamide (which forms naturally during the roasting process for all coffee). Interestingly, the acrylamide content of brewed coffee is many times’ greater than the maximum amount allowed in drinking water by the EPA.
All these reports, guidelines and regulations confirm the nearly universal presence of acrylamide in our diet, as well as provide scientific support for the development of government regulatory limits on the allowable levels of acrylamide in various food products. In fact, the European Commission is now moving toward establishing mandatory mitigation “codes of practice” and benchmark levels for foods and beverages sold in the EU as early as spring 2018, with maximum allowable levels possibly following after that.
This past summer, the EC commissioner for Health and Food Safety, Vytenis Andriukaitis, welcomed the EU’s authorizing vote enacting acrylamide mitigation measures and limits in a July 19 news release: “Today, we took an important step in protecting the health and well-being of citizens. The new regulation will not only help to reduce the presence of this carcinogenic substance but also will help raise awareness on how to avoid the exposure to it that oftentimes comes from home cooking.”
Given that it is very difficult to ensure consumers enact a permanent change in their food preparation habits, it makes much more sense for manufacturers to reduce acrylamide and the precursors to acrylamide at the factory source.
So far, however, workable solutions to the acrylamide problem have been hard to find, and food manufacturers will need robust and effective tools to meet anticipated acrylamide regulatory limits or voluntary reduction guidance. Today, though, an innovative non-GM yeast (Saccharomyces cerevisiae) with the ability to reduce acrylamide by up to 95 percent with minimal changes to the food production process is now available for precommercial review from Renaissance Ingredients Inc.
Using Yeast to Reduce Acrylamide
As mentioned, when starchy, carbohydrate-based foods such as potatoes, wheat, rice and other grains are heated above 120 °C (by frying, baking, roasting or toasting, for example), the naturally occurring amino acid asparagine reacts with sugars to form acrylamide. Although some yeast has an innate ability to consume asparagine, under most food processing conditions, this ability is minimal. Therefore, conventional yeast is not effective at mitigating the presence of acrylamide.
Instead, using a classic, adaptive evolutionary strategy to select for the yeast’s ability to quickly degrade asparagine in all conditions, Renaissance developed a non-GM yeast strain capable of quickly and easily reducing the incidence of this carcinogen in a wide variety of foods. Importantly, since yeast is a traditional food processing agent/ingredient that has been used safely for thousands of years, it is a natural fit for use by food manufacturers.
“Our research team has put years of work into developing our non-GM acrylamide-reducing yeast. We are extremely pleased with the efficacy, speed and simplicity of this important new advance in acrylamide mitigation,” says Dr. Matthew Dahabieh, president of Renaissance Ingredients.
Potato Fries and Chips: 70% Reduction in Acrylamide
Multiple studies from groups around the world confirm that french fries, chips and other fried potato products contain very high levels of acrylamide—up to 5,000 ppb in some cases. The popularity of fried potato products makes them a significant exposure threat to consumers given that they can provide 50 percent or more of the daily dietary acrylamide exposure of adults. In-house laboratory testing shows that its acrylamide-reducing (AR) yeast is highly effective in significantly lowering the levels of acrylamide in fried potato products.
For potato fries and chips, for instance, the ability of a “wash” of AR yeast in water was assessed for its ability to consume asparagine on the surface of the potato slices before deep-frying. The test found that a short soak (e.g., seconds to minutes just before the potato pieces are further processed, packaged and frozen) removes approximately 70 percent of the asparagine. Since there is less asparagine to begin with, the chips contain 70 percent less acrylamide after they are deep-fried by the restaurant or end consumer. Although using yeast in this process does not affect the taste or other attributes of the cooked product, if desired, any residual yeast on the outside of the potatoes can be easily removed by quickly rinsing the treated potatoes with fresh water before further processing.
Even better results can be expected when this AR yeast wash is applied to thinly cut potato products, such as shredded hash brown potatoes or finely sliced potato chips and fries. This is because the increased surface area of these thin pieces exposes much more asparagine for the AR yeast to remove.
“We’re confident we’ll be able to collaborate with industry partners to apply our AR yeast to a variety of potato products to deliver significant reductions in acrylamide. This method is robust, consistent and minimally disruptive to both product sensory attributes and current industrial potato processing practices,” says Dahabieh.
Bread and Bakery Products: 80% Reduction in Acrylamide
This AR yeast is a specialty baker’s yeast strain that recently received generally recognized as safe notification from FDA—the same status as conventional baker’s yeast—and can therefore supplement or replace the baker’s yeast currently being used widely in baking applications. Laboratory testing on white and whole wheat bread found that AR yeast consistently delivered an 80 percent reduction in acrylamide.
“The performance of our AR yeast in reducing acrylamide levels in bread by 80 percent has been excellent. These results confirm the seamlessness of using AR yeast in all varieties of baked goods,” notes Dahabieh.
Bread is a major concern given that acrylamide levels can rise significantly after toasting and other cooking practices common in homes and restaurants. In addition, bread and baked products can often account for a significant portion of the public’s daily exposure to acrylamide. In further laboratory testing, dark toast made from white bread leavened with conventional yeast contained up to 195 ppb of acrylamide—6.5 times more than the same piece of untoasted bread. Similarly, dark toast made from whole wheat bread contained up to 300 ppb—a level 8.5 times higher.
“Our AR yeast has demonstrated excellent consistency in reducing acrylamide by 80 percent across all levels of toasting,” Dahabieh explains. “In many cases, the acrylamide content of dark-toasted bread made with our AR yeast is less than that of untoasted bread made with conventional yeast. Essentially, our AR yeast eliminates the significant increase in acrylamide that is produced when bread and baked goods are toasted or cooked further at home.”
Consumer Cooking Can Greatly Increase Acrylamide Levels
As shown by the difference between bread and toast, end-user cooking practices can significantly raise acrylamide levels in all foods. This is a major concern for government regulators and food manufacturers; that is, while acrylamide levels can be reasonably low when foods leave the point of manufacturing, they can rise substantially when any asparagine remaining in the food is heated to high temperatures during home or restaurant cooking. This phenomenon can occur in any food that contains high amounts of unreacted free asparagine in the presence of reducing sugars, such as processed potato products and sliced bread. The longer a food containing asparagine is exposed to high temperatures during subsequent cooking stages, the more acrylamide will be produced, until potentially all of the asparagine has been converted into acrylamide.
“Our studies confirm that traditional restaurant and consumer cooking practices can result in elevated levels of acrylamide in toasted bread, processed potatoes or any food that has residual amounts of asparagine. The good news is that our data also show that AR yeast has the ability to lower this ‘acrylamide potential’ by degrading asparagine so that it is no longer present to form acrylamide in downstream cooking processes,” says Dahabieh. “We are now looking to engage with collaborative partners to confirm and refine the efficacy of AR yeast in scaled-up food manufacturing processes, so as to effectively lower both acrylamide levels and acrylamide potential in foods.”
Snack Food, Cereal and Other Extruded Food Products
This AR yeast can be used to supplement or as a replacement for conventional yeast in any snack food that already uses yeast as an ingredient. In addition, for non-yeast-containing foods such as processed potatoes, cereals or snacks, simple treatment methods can be developed to deliver the AR yeast during production to reduce acrylamide levels. Going even further, for food processes in which potato, wheat or other flours are combined with liquid, such as to be extruded into shapes or develop into coating mixes, incorporating AR yeast into the recipe allows for a significant amount of asparagine being consumed during the mixing process, reducing acrylamide levels in the final cooked product.
Looking to the Immediate Future
Renaissance Ingredients can be contacted by potential food-industry manufacturing partners to review the use of AR yeast in their unique products and processes in baking and other products. As mentioned, incorporating the AR yeast into almost any recipe can be accomplished with minimal process and product impacts, especially when yeast is already an ingredient. Processed potato products—which contain some of the highest levels of acrylamide of all foods investigated and which therefore receive the most negative news coverage—are another key market in which positive benefits could be achieved quite quickly.
Food manufacturers will undoubtedly welcome the food safety advance represented by this exciting, new clean-label product. Not only can this yeast reduce the health threat posed to both adults and children by acrylamide, but it also can illustrate the food industry’s commitment on behalf of customers to make their products as contaminant-free as possible. In short: Safety first.
Steve Campbell is a Vancouver, Canada-based communications consultant who writes for and about food technology companies. He can be reached at firstname.lastname@example.org.
2. Pedersen M et al. 2012. “Birth Weight, Head Circumference, and Prenatal Exposure to Acrylamide from Maternal Diet: The European Prospective Mother–Child Study (NewGeneris).” Environ Health Perspect 12:1739–1745.
3. Barrett J. 2012. “Crispy Cravings May Affect Baby’s Health: Prenatal Acrylamide Exposure Is Associated with Reduced Birth Weight.” Environ Health Perspect 12:a475.
4. Swedish National Food Administration. 2002. Analytical Methodology and Survey Results for Acrylamide in Foods.