Acrylamide is a chemical compound that forms naturally in starchy foods when they are cooked using high-temperature methods such as frying, baking, or roasting. This byproduct of the cooking process occurs when temperatures exceed 120°C (248°F). Laboratory tests indicate that acrylamide can cause cancer in animals, leading health organizations to conclude that dietary exposure presents a potential human health concern. Consumers can significantly reduce the amount of acrylamide they consume by implementing changes to food preparation and cooking practices.
How Acrylamide Forms in Common Foods
Acrylamide formation is linked to the Maillard reaction, the chemical process responsible for the browning and flavor development in cooked foods. This reaction involves an interaction between the amino acid asparagine and reducing sugars like glucose and fructose, which are naturally present in many plant-based foods.
The highest concentrations of acrylamide are found in carbohydrate-rich foods that undergo dry, high-heat processing. Primary sources include potato products, such as French fries, potato chips, and roasted potatoes, due to their high starch and asparagine content. Other major contributors are grain products like breakfast cereals, cookies, crackers, and toasted bread. Coffee is also a source, as the compound forms during the roasting of the beans.
Cooking Methods That Minimize Acrylamide Production
Temperature control during the application of heat is one of the most effective strategies for minimizing acrylamide formation. Generally, temperatures should be kept as low as possible while still ensuring the food is properly cooked and safe for consumption. For frying potato products, the oil temperature should ideally not exceed 175°C (347°F).
Monitoring the color of the cooked food serves as a practical visual guide for reducing acrylamide. Aim for a “golden yellow” color or lighter when cooking starchy items like potatoes or bread. Excessive browning or charring should be avoided, as the darker, crispier areas contain substantially higher levels of acrylamide.
Cooking time is equally important, as longer heating periods allow for greater compound accumulation. When baking or roasting, follow the minimum recommended cooking time and remove food from the heat as soon as it reaches the desired light color. Selecting moist cooking methods, such as boiling or steaming, rarely results in acrylamide formation because the food temperature does not exceed the boiling point of water.
Storage and Preparation Tactics
Modifying the food before it is cooked can significantly reduce the concentration of chemical precursors. Raw potatoes should be stored in a cool, dark location, such as a pantry, and not in the refrigerator. Storing potatoes below approximately 6°C (43°F) increases their reducing sugar content through a process called cold sweetening, which leads to higher acrylamide levels during cooking.
Preparing sliced potatoes by soaking them in water before frying or roasting can also lower the final acrylamide level. Submerging cut potatoes in water for 15 to 30 minutes helps to rinse away some of the free sugars and asparagine present on the surface. After soaking, the potato pieces must be thoroughly drained and blotted dry to prevent oil splatter during cooking and ensure proper browning.
Another effective preparation technique for cut potatoes is blanching, which involves briefly boiling the food before the final high-heat cooking step. This process reduces the levels of both free asparagine and sugars within the potato flesh, limiting the reactants available for the Maillard reaction. For grains and rice, a simple rinsing before cooking may help to wash away some surface sugars, offering a minor reduction benefit.