Substitution of certain ingredients could reduce acrylamide content of finished products by as much as 70 per cent, say Swiss researchers.
The new study, a collaboration between the Institute of Food Science and Nutrition at ETH Zurich and the Swiss biscuit manufacturer Kambly, reports that substitution of key ingredients could significantly reduce the acrylamide content of a semi-finished biscuit product.
"Experiments on an industrial scale with a semi-finished biscuit gave evidence that these three approaches are feasible and that the sensory properties of the semi-finished products as well as the finished products conform to a high-quality standard expected by the food industry and the consumer," wrote lead author Maya Graf in the journal LWT Food Science and Technology.
Acrylamide is a carcinogen that is created when starchy foods are baked, roasted, fried or toasted. It 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 researchers, led by Renato Amado from ETH Zurich, looked at the effects of replacing the baking agent ammonium hydrogencarbonate with sodium hydrogencarbonate, an inverted sugar syrup with a sucrose solution, and addition of extra tartaric acid on the acrylamide content of a biscuit.
Since the biscuit produced was a semi-finished product that is not consumed directly but ground to crumbs and used in further biscuit production, the researchers also looked at the effect of a second baking process.
Batches of 410 kg of biscuit dough were prepared by using type 550 wheat flour, water, powdered sugar (sucrose), vegetable fat, sodium chloride, milk powder, inverted sugar syrup, a starch preparation, and a baking agent.
The baking agent used was either a combination of both ammonium hydrogencarbonate and sodium hydrogencarbonate, or the latter by itself.
After five minutes of baking at 225 to 230 degrees Celsius, the researchers found that the acrylamide content of the biscuit was reduced by 70 per cent if sodium hydrogencarbonate was used alone.
The use of sucrose syrup also decreased the acrylamide content by a similar magnitude if used in place of an inverted sugar syrup.
However, lead author Maya Graf stressed that this measure is "limited to products where the browning is not of primary importance."
Addition of extra tartaric acid, an organic acid often used in baking with sodium hydrogencarbonate to improve leavening, was found to reduce the pH of the biscuit mix and thus affect acrylamide formation.
By including 244 g of tartaric acid, an increase of almost 50 g per 100 kg from the standard preparation, the researchers found that the acrylamide content of the semi-finished biscuits was reduced by almost a third.
"However, the amount of acid to be acid may be limited, mainly for sensory reasons," said Graf, referring to the possible production of an acidic taste.
"Other groups of bakery products may behave differently," concluded Graf, "especially the leavening and the texture might be critical points if the product is directly consumed."