(fw) Acrylamide hit the headlines in the media not so long ago. Swedish researchers discovered in 2002 that this carcinogenic compound is formed in the corresponding foodstuffs when they are baked, roasted, fried or toasted. Subsequently there were numerous studies to investigate how the acrylamide level in such foods could be reduced. In collaboration with the biscuit manufacturer Kambly, researchers at ETH Zurich’s Institute of Food Science and Nutrition have now shown how this can be achieved for biscuits. (1)

Industrial manufacture

Led by Felix Escher and Renato Amadò, the researchers concentrated their analyses essentially on the baking powder and sugar. They already knew from earlier studies that these factors play a decisive part. The food technologists tested various recipes in extensive experiments in the factory. “Our study enabled us to show that the suggested modifications work on an industrial scale,” explains Thomas Amrein, the doctoral student responsible for the study. “The remit from Kambly was clear: the high quality of the products must not be impaired in any way.”

What actually happened was that the manufacture of the biscuits, which undergo further processing in a second step, was examined in minute detail. These semi-finished products are of interest because acrylamide can also be formed during the second baking process. However it turned out that the new recipes can also reduce the formation of acrylamide in a second baking process.

A 70 percent reduction

The level of acrylamide in the biscuits can be reduced by up to 70 percent if sodium bicarbonate is used as baking powder instead of ammonium bicarbonate. Replacing what is known as invert sugar, a mixture of glucose and fructose, with a solution of sucrose (i.e. with ordinary household sugar) also lowers the concentration of the problem substance dramatically.

Adding a larger amount of tartaric acid also has beneficial effects. In practice this is often used as an additive when sodium bicarbonate is employed as the raising agent. However, Amrein explains that the opportunities for reducing acrylamide formation by using tartaric acid are limited. “If too much acid is added, this has an adverse effect on the taste and colour. That is exactly what we wanted to prevent.”