New research suggests that different cooking practices can affect the concentration of a cancer-causing chemical in French fries.

At first glance you may assume that French fries hand cooked in a swanky restaurant are healthier than their fast food counterparts, which are produced in vast quantities numbers using automated machines.

Think again. A study suggests that the levels of a chemical called acrylamide are actually highest in more upmarket restaurants’ fries because of the way they are cooked.

Acrylamide is a chemical found in many processed foods, including French fries. Recent studies have suggested it has the ability to alter our DNA and cause cancer. The chemical is only harmful in very high concentrations, but food manufacturers and policy makers alike are keen to minimise heath risks and find ways to reduce acrylamide intake.

Acrylamide is known to arise in French fries while they are heated to high temperatures during the frying process, but concentrations can vary greatly. To find out more, a group of scientists from Universiti Putra Malaysia (UPM) and Wageningen University in the Netherlands decided to investigate how different cooking practices altered French fries’ chemistry.

They focused on three types of eateries: fast food establishments, institutional caterers (such as those found in schools and businesses) and restaurants. They took samples of French fries from each and measured their acrylamide content, noting the frying temperature, frying time and whether or not frozen fries were thawed prior to frying.

Higher temperatures and longer frying times were associated with higher acrylamide concentrations. Thawing also seemed to make a difference, with fries thawed prefrying having lower concentrations of acrylamide than those that were fried straight from being frozen.

Overall acrylamide concentration was lowest in fast food outlets and highest in restaurants. This may be because in fast food outlets fries were thawed, and then cooked at a precisely controlled temperature for a set amount of time using automated machinery. In restaurants, on the other hand, fries were cooked in a frying pan straight from being frozen, so frying temperatures and times were a lot harder for staff to keep track of.

The insights provided by this study will be used to develop better preparation guidelines for food service establishments, which will hopefully contribute to a sustainable reduction in acrylamide intake.

M. Sanny, S. Jinap, E.J. Bakker, M.A.J.S. van Boekel, P.A. Luning (2011) “Possible causes of variation in acrylamide concentration in French fries prepared in food service establishments: An observational study” Food Chemistry 132 p134-143

For further information contact:

Professor Jinap Selamat
Faculty of Food Science & Technology
Universiti Putra Malaysia