Compounds from grape seeds called proanthocyanidins had the greatest acrylamide reduction potential, with a 62.2% reduction reported in potato starch-based foods, according to findings published in the Journal of the Science of Food and Agriculture.
In different foods, such as cookies, researchers from the University of Hong Kong and the Republic Polytechnic in Singapore report that clove bud extracts were the most effective, with a 51% reduction of acrylamide observed when used at a level of 4%.
“This study may provide some valuable information on using dietary plant materials as additives/ingredients to mitigate acrylamide formation for developing healthy foods,” wrote the researchers, led by Yi-Zhong Cai from the University of Hong Kong.
The acrylamide story
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.
Current commercial approaches
Approaches already used by the food industry to help reduce acrylamide levels include converting asparagine into an impotent form using an enzyme, binding asparagine to make it inaccessible, adding amino acids, changing the pH to alter the reaction products, cutting heating temperatures and times, and removing compounds from the recipe that may promote acrylamide formation.
Enzymes such as DSM’s Preventase and Novozyme's Acrylaway, work by converting asparagine into aspartic acid, thereby preventing it from being converted into acrylamide. The effect is a reduction in acrylamide in the final product by as much as 90 per cent.
While the plant extracts used in the current study do not achieve reductions as high as these enzymes, there appears room for improvement.
The researchers tested the acrylamide-inhibiting activity of a range of plant extracts, including cinnamon, clove, coriander, cumin, turmeric, and grape seed.
Results showed that, of all the extracts tested, the best performance for reducing the level of acrylamide in cookies by 51% when used at a level of 4%. In addition, aqueous extracts performed better than raw powder, said the researchers.
In a potato-starch based food system, the best performance was observed for proanthocyanidins from grape seeds (62% reduction), followed by an aqueous extract of clove buds (57%).
“It may be feasible to use some of the tested dietary plant materials to reduce acrylamide formation in cookies and other starchy foods,” concluded the researchers.
Source: Journal of the Science of Food and Agriculture
Volume 91, Issue 13, pages 2477-2483, DOI 10.1002/jsfa.449
“Dietary plant materials reduce acrylamide formation in cookie and starch-based model systems”
Authors F. Zhu, Y-Z. Cai, J. Ke, H. Corke