The application of heat to a food can change the taste of that certain food so that it seems to be entirely different. Here’s how:
By subjecting food to heat we are able to change its color, texture, form and flavor. For instance, as meat cooks in the oven, it shrinks and its shape changes. It goes from deep red to reddish brown. The soft texture of the uncooked meat fibers hardens and then tenderizes which changes the flavor. Fats in the tissues melt. You may notice that some fat escapes from the pan from even the best trimmed piece of meat. When meat is cooked properly, the fat and juices are dispersed among the fibers to make the meat tender. Meat that is over cooked loses too much juice and liquefied fat. Meat that is undercooked will retain its juices but the proteins will not be sufficiently cooked and the muscle will be tough.
Some foods that are heated together become completely changed and form something quite different from the original. An example would be gravy; the butter, flour and liquid, which originally have individual identities, are joined into one by heat. Slow and gentle heat makes the flour swell and absorb the liquid.
The same processes take place in vegetables and fruits; the harder fibers are softened and the starchy elements absorb liquid. Overcooking fruit makes the fibers soft and it loses its shape and becomes mushy. If you want to make jelly, the fruit should be cooked until it is completely shapeless; then it is strained to make the jelly.
Some vegetables, such as spinach, contain so much liquid that you do not need to add more for cooking. More starchy vegetables, like potatoes, need some liquid to make their starches swell and soften.
Cooking heat can be applied in many ways.
1. Hot liquid as in boiling, simmering, blanching, poaching and scalding.
2. Hot bath such as frying as in fat (or in deep fat) where foods such as French fries are immersed in the fat.
3. Hot metal as when a steak is pan broiled, or where any food is cooked in greaseless pans.
4. Radiation, where the heat is given off by the red hot coils of an electric stove unit or by the flame of the gas stove or charcoal of a barbecue.
5. Trapped heat, which is the heat contained in ovens of various kinds. This type of heat combines two basic principles: Part of the baking is done by heat coming from the hot metal walls and grill of the oven and is therefore radiant heat; the other part of the baking is done by the trapped heat, the heated air. When the oven door is opened, part of the heated air from the oven escapes and the oven temperature is reduced. This explains why oven doors should be opened as few times as possible when a delicate food like a cake is baking.
The heat adjustments between a gas and electric stove are different. On a gas stove, the degree of heat can be changed almost instantly. It takes somewhat longer for the heat to increase or decrease on an electric stove. You will have to watch your foods closely to make sure that they are not overcooked. Take your pan of food off of the stove immediately instead of just turning off the heat.
The effects of cold and heat on your foods can change their taste and texture dramatically. Some people may love raw carrots but hate them when they are cooked. Knowing how heat can affect the foods that you eat will help you become a better cook.