What term is used to describe fat that has taken up oxygen and released hydrogen?

The term that best describes fat that has taken up oxygen and released hydrogen is "rancid." When fats undergo oxidation, they react with oxygen in a process that can lead to the formation of free radicals and other compounds, resulting in off-flavors and odors commonly associated with rancidity. This process can significantly affect the quality, safety, and nutritional value of food products containing fats.

Rancidity signifies that the fats have degraded, often leading to undesirable sensory qualities. The process of fats becoming rancid is linked to various factors, including exposure to heat, light, and air. Understanding rancidity is particularly important for food science as it impacts food storage, shelf life, and consumer acceptance.

The other options do not accurately describe the situation where fat has interacted with oxygen. For instance, "oxidized" might refer to the process that leads to rancidity, but it does not specifically denote the state associated with the release of hydrogen. "Hydrogenated" refers to the process of adding hydrogen to unsaturated fats, which is often done to make them more stable and solid at room temperature, while "dehydrated" pertains to the removal of water rather than the interaction of oxygen with fats.