EU reveals acrylamide recommendations
recommendations on how companies can change their processes to
lower the formation of the chemical by up to 80 per cent when
manufacturing susceptible foods.
In a final report issued this week, the EU-funded Heatox project collected additional advice for those manufacturing potato, cereal and coffee products. The project's findings adds to growing accumulation of methods to reduce acrylamide as collected in a series of guides collected by the Confederation of the Food and Drink Industries of the EU (CIAA). The CIAA's acrylamide 'Toolbox' guides are targeted at the EU's small and medium sized companies, which may not have the necessary resources to adequately research methods developed by their larger competitors. The Heatox researchers consulted with the CIAA during the project period, and some of the findings of the project were added to the industry toolbox. The additional advice issued this week is expected to be added to the CIAA's guides. The Toolbox focuses on french fries and crisps, bread, bakery wares, and breakfast cereals, and coffee. In the area of potato products, the Heatox researchers say they have found that blanching in combination with acid treatment, has a great potential to reduce the acrylamide levels in crisps as well as in French fries. Blanching could typically reduce the acrylamide level by 50 per cent in crisps, the researchers stated. With acidic blanching, using citric or lactic acid, researchers found that acrylamide levels were reduced by about 80 per cent in French fries. The products did not have a significant acidic aftertaste as evaluated by expert panels. The researchers also studied the influence of frying conditions. They developed a fry simulator - a computational model estimating the impact of various processing parameters on the formation of acrylamide in French fries. "For crisps very promising results have been obtained with vacuum frying, in particular in combination with pre-treatment involving blanching and acid treatment," they stated. Heatox researchers also worked on cereal products, focussing on bread and baking. They performed studies all the way from the raw materials to the final baking processes. They claimed to have shown that the asparagine content of the grain or flour is decisive for the acrylamide level in the bread. "The bran and germ fractions are especially high in asparagine, so the composition of the flour mix is of great importance," they advise. "However, whole grain products are beneficial from many nutritional points of views so the risk to benefit balance must always be taken into consideration." Yeast fermentation also plays an important role in influencing the final acrylamide level, they discovered. "Prolonged fermentation may be an efficient way to minimise the acrylamide formation," they stated. "We have shown that the fermentation not only reduces the sugar content in the dough, but also specifically decreases the asparagine content." Free asparagine may be reduced also by sour dough fermentation. However, the bakers yeast may be less effective during a following yeast fermentation, they stated. "We have also shown that the formation of acrylamide during baking may be reduced by addition of free glycine," they stated. All the findings on cereal products have since been incorporated in the CIAA Toolbox, they noted. The scientists also claim to have shown that the use of steam during the final part of the baking process is a possible way to reduce the acrylamide formation. In one example they managed to reduce the acrylamide level by 40 per cent with no significant changes of the sensory quality of the bread. They also evaluated new alternative baking technologies, such as air jet impingement and infrared radiation heating. With infrared heating they have examples of reducing the acrylamide level by 60 per cent with retained sensory properties, Heatox reported. The evaluation of the new technologies are in the process of being published and have not yet included in the Toolbox. "Concepts like these have to be seen as options that have to be optimised for each specific application," they cautioned. Coffee processing was another study area within Heatox. The researchers studied the roasting process and evaluated the influence of raw material parameters. They investigated various coffee bean varieties and found that the choice of coffee bean is important in acrylamide formation. For example Arabica tends to form less acrylamide than Robusta. Acrylamide levels also decrease with an increased degree of roasting, they found. "However, this knowledge is very difficult to implement rapidly into practical minimisation actions, since the roasting and the choice of coffee bean are the key determinants for the flavour properties of the final product, and flavour is the main characteristic for a specific brand or product," they stated. They also noted that the coffee roasting process is not very well understood by science. "We don't know what other substances may be formed when the process is changed," they stated. "Our findings regarding coffee are in concordance with what is presented in the Toolbox." The main finding of the study was the conclusion that acrylamide and 50 other heat-induced compounds in foods may cause cancer. The study adds to the accumulating evidence that acrylamide, formed in foods during heating or frying processes, poses a health problem, and puts more pressure on processors to reduce the chemical in their products. Reduction may involve reformulation, revising processing and cooking times, or the use of varieties of ingredients that do not result in as much acrylamide formation as their counterparts. Heatox was launched to fill in the gaps on the formation of acrylamide in cooked foods and provide advice to industry. The team found toxicological evidence suggesting that acrylamide in food may cause cancer, Hetox reported. "Their findings also suggest that there are ways to decrease exposure to acrylamide, but not to eliminate it," the report stated. "Laboratory experiments succeeded in reducing acrylamide levels in bread and potatoes by adjusting the oil to potato ratio in semi-industrial fryers or minimising long yeast fermentation." They calculated that successful application of all presently known methods would reduce the acrylamide intake by 40 per cent at the very most. The Heatox project also found that acrylamide is not the only genotoxic compound that forms when food is heated. The scientific team has created a database of about 800 heat-induced compounds, of which they say 52 are potential carcinogens based on their chemical structure. "Other compounds formed during cooking of food, for example HMF, Furan, and a variety of Maillard reactants and lipid oxidation products may also constitute an increased cancer risk for consumers," they stated. Future research should focus on these compounds, the researchers advised in the report. Acrylamide appears to form during processing as a result of a reaction between specific amino acids, including asparagine, and sugars found in foods reaching high temperatures during cooking processes. The process is known as the Maillard reaction. This occurs at temperatures above 100°C (212°F). Acrylamide hit the headlines in 2002 when scientists at the Swedish Food Administration first reported unexpectedly high levels of the potential carcinogen in carbohydrate-rich foods cooked at high temperatures. Until then acrylamide was known only as a highly reactive industrial chemical, present also at low levels for example in tobacco smoke. Since the Swedish discovery a global effort has been underway to amass data about this chemical. More than 200 research projects have been initiated around the world, and their findings co-ordinated by national governments, the EU and the United Nations. The EU three-year project began in November 2003, bringing together 24 research teams from 14 countries. Most project partners are universities or research institutes, but national authorities and a European consumer organisation are also involved. The Heatox project has also produced intake calculations, chemical reaction models, exposure assessments, in vivo and in vitro toxicity testing, mitigation proposals to reduce intake, analytical methods for biomarkers and levels and a risk characterisation, of the chemical. About 40 individual research papers have been published in international scientific journals by Heatox's scientists as a result of the project. The data was used to produce a six-page acrylamide reduction guide for food processors, one that complements those already produced by EU industry for various food sectors. Last year the European Commission called on member states to check annually whether acrylamide levels are falling, serving to put additional pressure on processors to reduce the chemical in their products. The Commission is asking member states to perform the surveys annually in 2007, 2008 and 2009. In 2005, the European Food Safety Authority (EFSA) endorsed a the risk assessment on acrylamide in food, which was carried out by the Food and Agriculture Organisation and the World Health Organisation. In that assessment the UN organisations concluded that the margins of exposure for average and high consumption consumers were low for a compound that is genotoxic and carcinogenic and that this factor may indicate a human health concern. Earlier this month scientists who conducted a study of about 62,000 women in the Netherlands concluded that increased dietary intakes of acrylamide could raise the risk of endometrial and ovarian cancer by 29 and 78 per cent, respectively. A wide range of cooked foods - prepared industrially, in catering, or at home - contain acrylamide at levels between a few parts per billion (ppb) to over 1000 ppb. The foods include bread, fried potatoes and coffee as well as specialty products like potato crisps, biscuits, crisp bread, and a range of other heat-processed products. To view the final Heatox report go to www.heatox.org.