What type of connective tissue is heat resistant and does not change during cooking?

The correct answer is elastin. This type of connective tissue is known for its toughness and elasticity, which allows it to withstand changes in heat without breaking down during cooking processes. Unlike collagen, which tends to soften and break down when exposed to heat, elastin retains its structure even after prolonged cooking.

Elastin is primarily found in certain animal tissues, particularly in the connective tissues of tendons and ligaments, where its ability to return to shape after stretching is essential for the functionality of these structures.

The other options, while important types of connective tissues, involve changes when exposed to heat. Collagen, for example, becomes more tender when cooked, particularly when moist heat is applied over time, as it converts to gelatin. Fibrous tissue is a broader category that can include collagen as well, making it inherently more susceptible to heat. Adipose tissue is primarily fat and does not possess the properties associated with elastin or collagen in the context of cooking temperatures.