When food becomes tough and chewy after being heated in a microwave, it is often due to the overcooking or uneven heating of certain components within the food.
Loss of moisture: One common reason for food becoming tough and chewy in the microwave is the loss of moisture. As mentioned earlier, microwaves primarily interact with water molecules in the food to generate heat. During the heating process, water molecules can evaporate, causing the food to dry out. When food loses its moisture content, it can become dry and tough.
Uneven heating: Microwave ovens work by emitting microwaves that penetrate into the food and generate heat. However, microwaves can create hotspots or areas with more intense heating in certain parts of the food, while other areas may remain relatively cool. If the food is not stirred or rotated during the cooking process, some parts of the food might become overcooked and tough, while others remain undercooked.
Protein denaturation: Proteins in food can also be affected by microwave heating. When proteins are exposed to high temperatures, their molecular structures can change, a process known as denaturation. This denaturation can lead to the proteins becoming less tender and more chewy.
Starch gelatinization: In some cases, foods that contain starch can become chewy in the microwave. Starches in food can undergo gelatinization when heated, which involves the swelling of starch granules and the release of water. However, if the gelatinization process is not properly controlled, the starch can become overly firm and make the food chewy.
To avoid food becoming tough and chewy in the microwave, it's essential to pay attention to cooking times, stir or rotate the food during the cooking process, and use microwave-safe coverings or microwave-safe containers to help retain moisture and prevent overcooking. By practicing proper microwave techniques, you can achieve better results and maintain the desired texture of the food.