What causes foods to brown during cooking?

Foods brown during cooking primarily due to caramelization of sugars when exposed to heat. This process occurs when sugar molecules break down and form new compounds, resulting in a rich color and complex flavors. Caramelization typically begins at temperatures of around 320°F (160°C), leading to the desirable browning seen in a variety of foods, such as sautéed vegetables, roasted meats, and baked goods.

This browning is not only visually appealing but also contributes to the development of flavors that are a hallmark of well-cooked dishes. The Maillard reaction, another browning process, can also occur alongside caramelization when proteins and sugars react under heat, adding further depth to the flavor and color.

Other factors like the presence of additives or mixing with acidic ingredients do not directly cause the browning effect in the same way as caramelization does. Oxidation of nutrients can lead to color changes in some instances, but it is primarily associated with degradation rather than the desirable aesthetic and flavor enhancements achieved through caramelization and the Maillard reaction.