Research groups in Switzerland and the UK have discovered why potato crisps and certain baked foods carry high levels of a dangerous cancer-causing agent. The findings could have implications for food safety.
The recent discovery that crisps, crackers and some baked goods contain high levels of the nerve poison and probable carcinogen, acrylamide, sent shock waves through the food industry. It meant that some of the most popular snacks and roasted foods represented a cancer hazard as a result of the necessary cooking process.
Separate teams at the Nestlé Research Centre in Lausanne and the University of Reading have now discovered how the cancer agent gets into the food, and are publishing details of the acrylamide mystery today in the journal Nature.
Potatoes and most cereals, particularly rye, are rich in an amino acid called asparagine. The researchers found that asparagine changes into acrylamide at standard baking temperatures when in the presence of sugar and a solvent such as water. Asparagine is the main amino acid in potatoes used for the manufacture of crisps, representing 40 per cent of the total amino acid content.
About 14 per cent of the amino acid in wheat is asparagine and 18 per cent in high-protein rye flour.
The interaction between the amino acid, sugar and water is known as the "Maillard reaction", the research teams note.
"Products of the Maillard reaction are responsible for much of the flavour and colour generated during baking and roasting," the Reading authors said.
Yet the very chemical reactions needed to make crisps and crackers appealing to the eye and palate are also responsible for producing the harmful acrylamide.
"Our findings indicate that the Maillard-driven generation of flavour and colour in thermally processed foods can under particular conditions be linked to the formation of acrylamide," the Swiss team noted.
The findings could have implications for food safety. It may be possible to find cereal and potato varieties with lower levels of asparagine.