Dry food containing low amounts of carbohydrates are at risk of increased acrylamide levels, says a new study sponsored by the European Science Foundation.
Formulating foods with oils with a reduced susceptibility like palm oil are likely to have lower acrylamide levels, particularly fat-rich and sugar-free foods, according to findings published in Food Research International.
The presence of antioxidants was found to reduce the formation of acrylamide, said the researchers, with the effects linked to a prevention of fat oxidation.
“These findings suggested that lipid oxidation could become a relevant factor for acrylamide formation, particularly for dry foods with low carbohydrate content,” wrote the researchers, led by Vincenzo Fogliano from the Department of Food Science at the University of Napoli “Federico II”.
Acrylamide is a suspected carcinogen that is formed during by heat-induced reaction between sugar and an amino acid called asparagine. Known as the Maillard reaction, this process is responsible for the brown colour and tasty flavour of baked, fried and toasted foods.
Despite being a carcinogen in the laboratory, many epidemiological studies have reported that everyday exposure to acrylamide in food is too low to be of concern.
The compound first hit the headlines in 2002, when scientists at the Swedish Food Administration first reported unexpectedly high levels of acrylamide, found to cause cancer in laboratory rats, in carbohydrate-rich foods.
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 Italian researchers, in collaboration with scientists from Turkey, formulated a range of fat-rich model systems and measured acrylamide levels following heating.
Results showed that the degree of oxidation of the fat was a significant influence on acrylamide formation. Indeed, “the effect was more evident in sugar-free system where lipid become the main sources of carbonyls”, said the researchers.
“In the sugar-containing model systems, lipid oxidation level moderately influenced the acrylamide formation, while the effect became more pronounced in the systems with low water content and with low carbohydrate concentration such as for example roasted nuts, seeds or pulses,” they added.
The subject of antioxidants and acrylamide is “controversial”, said the researchers, but results from their study indicated that antioxidants like catechins could protect against acrylamide formation “related to the inhibition of the formation of lipid oxidation products”, they added.
The type of oil or fat used in the formulation also influences acrylamide levels, said the researchers with acrylamide formation higher in systems containing sunflower oil than in systems made with palm oil which has a lower susceptibility to oxidation, they added.
Source: Food Research International
Published online ahead of print, doi: 10.1016/j.foodres.2010.01.013
“Lipid oxidation promotes acrylamide formation in fat-rich model systems”
Authors: E. Capuano, T. Oliviero, O.C. Acar, V. Gokmen, V. Fogliano