Storing food safely - potatoes
Uncooked potatoes are best kept somewhere cool and dry, but don't keep them in the fridge. Putting potatoes in the fridge can increase the amount of sugar they contain, and lead to higher levels of a chemical called acrylamide when the potatoes are baked, fried or roasted at high temperatures.
Acrylamide is a chemical found in starchy foods that have been cooked at high temperatures. These include crisps, chips, bread and crispbreads. It was first discovered by scientists in Sweden in 2002.
Acrylamide causes cancer in animals and so might also harm people's health.
Acrylamide is produced naturally
Acrylamide is produced naturally when starchy foods are cooked at high temperatures. From the research available so far, it seems that boiling food doesn't produce acrylamide.
It isn't possible to stop acrylamide being produced or to remove it from foods once it has been produced. Therefore, research is being carried out to find out how the levels of acrylamide produced in food can be reduced.
home-cooked foods compared to processed foods
The Food Standards Agency (FSA) has carried out research including tests on pre-cooked, processed and packaged foods, plus chips that were prepared from potatoes and cooked by the researchers. High levels were found in the home-cooked foods and in the processed foods.
Cooking and storing potatoes
If you want to help reduce the amount of acrylamide in your diet, here is some advice on cooking and storing potatoes.
Potatoes should be kept somewhere cool and dry but not in the fridge. This is because putting potatoes in the fridge can increase the amount of sugar they contain, this could lead to higher acrylamide levels when the potatoes are roasted, baked or fried at high temperatures.
Additionally, research carried out by the FSA has shown that if you are making your own chips, they contain less acrylamide when they are cooked to a lighter colour than chips cooked to a darker colour.
You can also reduce acrylamide levels by soaking potatoes in water for 30 minutes before frying them. But remember excess water should be dried off before putting the chips into hot oil. If you are using frozen chips, the levels of acrylamide are lower when the cooking instructions on the packaging are followed.
Continued research in to acrylamide
The FSA has carried out its own research, which confirmed the original findings of the scientists in Sweden who discovered acrylamide. The FSA has also played a significant role in contributing to European and international efforts to find out how acrylamide forms in food.
Although some studies have already been carried out, further research is needed to work out how best the issue might be resolved. As part of the international efforts to investigate acrylamide, the FSA is continuing to fund research.
The FSA's research includes projects investigating acrylamide in the UK diet, the effect of home cooking on acrylamide, how it is formed, and how levels can be reduced. The main aim is to minimise the amount of acrylamide present in food.
Legal limits for acrylamide in food
There is no general limit set for acrylamide in food because levels of this sort of chemical should be kept as low as is reasonably practical. There is a legal limit set for acrylamide from plastics used in contact with food, such as packaging, so that acrylamide from this source should not be found in food at levels at or above 10 parts per billion.
The FSA is working with the food industry to increase knowledge and understanding. As part of the international effort, the food industry is also carrying out research to find ways of reducing the levels of acrylamide in food.