Extracts of green tea and bamboo leaf could reduce acrylamide formation in foods, suggests a new study from China.
Researchers from Zhejiang Universitys Department of Food Science and Nutrition investigated the potential of the antioxidant-rich extracts to reduce acrylamide formation in an asparagine-glucose model system.
"Results of mitigation effect on the generation of acrylamide showed that both antioxidant of bamboo leaves (AOB) and extract of green tea (EGT) could effectively reduce the formation of acrylamide and achieve a maximum reduction rate (74.4 per cent for the use of AOB and 74.3 per cent for the use of EGT) when the addition levels of AOB and EGT were both 0.1 micrograms," wrote Yu Zhang and Ying Zhang in the Journal of Food Engineering.
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.
Addition of AOB or EGT to the asparagine-glucose model system was tested at 180 degrees Celsius in an oven under low-moisture conditions. The active components of the extracts identified by the researchers as reducing the acrylamide formation were homoorientin and epigallocatechin gallate (EGCG), for AOB and EGT, respectively.
A kinetic study showed that the extracts worked during the formation stage, and prolonged this stage, resulting in less production over a shorter period of time. No effect was observed during the elimination stage, indicating the extracts did not affect the acrylamide once formed.
"Results demonstrated that addition of AOB and EGT could significantly affect the formation kinetic behavior of acrylamide in the low-moisture model system," wrote the researchers.
"Further studies in this domain will focus on the kinetic behavior of acrylamide affected by addition of natural antioxidants in some representative food matrix models such as potato-based model," they concluded.
The research follows similar results from the same group that reported earlier this year the potential of the bamboo leaf extract to reduce acrylamide formation in French fries and potato crisps (J. Agric. Food Chem., doi: 10.1021/jf062568i)
Source: Journal of Food Engineering (Elsevier)
Published on-line ahead of print, 2 August 2007, doi: 10.1016/j.jfoodeng.2007.07.013
"Effect of natural antioxidants on kinetic behavior of acrylamide formation and elimination in low-moisture asparagine-glucose model system"
Authors: Yu Zhang and Ying Zhang