New research out of the US suggests that the amount of the potentially carcinogenic substance acrylamide in fried or baked starch foods depends on the length of time for which the foods were heated.

Since Swedish scientists discovered acrylamide in baked potatoes, crisps and other starchy foods cooked at high temperatures earlier this year, research authorities around the world have been conducting their own research.

Tests unveiled by the US Food and Drug Administration show differing levels of acrylamide even within the same brand of food, reports Nationwide News. For instance, FDA researchers tested hot chips purchased from four restaurants belonging to the same fastfood chain, and reported a threefold disparity between the batches with the highest and lowest levels of acrylamide.

Moreover, they tested 25 identical bags of crisps, but only two of these bags had precisely the same level of acrylamide.