Transcript Chapter 18
Chapter 18 Cooking principals What is cooking? Is the process of preparing food for eating by applying heat The ability to cook food meant a longer, healthier life Foods are cooked because: Cooked food is safer to eat Cooked food is more digestible The texture, taste aroma, and appearance of foods are improved What happens to foods as they are cooked Microorganisms are destroyed Most bacteria, fungi, and molds are killed by temperatures above 135 Once cooked to this temperature it must be held at this temp Connective tissue in meats breaks down Heat is used to make tough pieces of meat and poultry tender and easier to eat Connective tissues are tough fibers that hold the muscles together, and becomes tender when it is properly cooked Proteins coagulate When heated many solidify or become firm. Coagulation is the reason the texture of many foods change when cooked Fibers in vegetables break down Makes up the cell structure of most plants are broken down with heat This makes cooked vegetables tender and release nutrients Starches absorb liquid Are used to thicken liquids such as sauces and soups Many starches must be heated in order for the thickening process to take place When starches are combined with a hot liquid, they absorb the liquid like a sponge and swell in a process called gelatinization Flavors blend and change Flavors change when raw food is cooked The most common flavor change is the caramelization of sugars, resulting in richer, more complex aroma and flavor Flavors of proteins are also changed by heat, amino acids change when heated create new flavors It also helps to blend or marry the flavors multiple ingredients Effects of overcooking Monitoring timing and temperature is essential to achieve the proper degree of doneness Things that happen if food is overcooked: Texture is destroyed and foods become mushy and disintegrate, or tough and stringy Proteins will curdle or toughen Moisture is lost Sugars burn causing a bitter taste Green vegetables loose color Nutrients are lost and destroyed Methods of heat transfer How heat is transferred to the food has a distinct effect on how the finished product will turn out Cooking methods use conduction, convection, or radiation Conduction: Is the transfer of heat energy from one object to another through direct contact Heat is conducted from the heating element through pots and pans to the food Convection: Is the manner in which heat energy travels through liquids and gases. Natural convection occurs when warm air rises to the top of the oven when a warmer liquid rises to the top of the pot Convection oven circulates air with a fan Radiation: Is the transfer of heat energy through waves No conductor is necessary to cook with radiation A broiler transfers heat to food by a means of radiation Microwaves cook food by radiation, through not heat radiation Cooking methods Methods used to cook foods can be classified as: Dry heat Moist-heat Combination methods- combine both dry heat and moist heat in the same recipe Some cooking methods transfer heat using two or more of these Dry heat methods: Transfer heat to food by conduction, hot air convection, or radiation Many dry heat methods begin with a high temperature to create browning and improve flavor They do not break down fibers or connective tissues as well as moist methods This type of cooking is often used with tender products Dry heat methods include sautéing panfrying, deep frying, grilling, broiling, roasting, and baking Sautéing: Means to quickly cook an item in a small amount of hot fat over high heat Sauté in French means to jump Sautéing is traditionally done in a sauteuse, and it can also be done in a griddle or in a wok Meat, poultry, seafood, vegetables, and starches can all be sautéed Sautéing transfers heat through conduction Sweating is cooking food in a small amount of fat using low heat in order to soften the food without browning, typically used with onions, garlic, mirepoix. panfrying Uses hot fat to cook a food item It cooks the food in enough hot fat to cover it halfway The food is turned during the cooking process in order to cook the food completely May also be called shallow fat frying Large or thick pieces of meat, fish or poultry can be pan fried Heat is transferred through conduction Deep frying Is a method that cooks food in enough fat to fully cover them Enough fat must be used in order to have proper cooking, if too little is used it is hard to maintain the fats high temperature when food is added Results from not using enough oil is a limp and greasy rather than crisp Most deep fried foods are coated with flour, breading, or batter before being fried This method transfers heat by convection Grilling Cooking method that uses radiation from a heat source located below the food Can be cooked over a variety of heat sources, gas, electric burners, charcoal, or hard wood Juices dripping from the food on the flames creates smoke, which is often used to add flavor to the food It produces a robust flavor and is a healthy way to cook Broiling Uses radiation from a heat source located above the food Often used as a finishing process to brown cooked foods Gratiner means to brown a foods product Browned foods are often described by the French term au Gratin Roasting Was originally done by turning meat placed on a spit or skewer over the radiant heat of a fire Today it is mostly done in the oven Cooks food by surrounding it with hot air, during cooking the food is uncovered so the moisture released can evaporate The product to be roasted is placed on a rack so air can circulate evenly on all sides Baking Baking is done in an oven Is used to cook foods with a certain amount of moisture, the moisture might be a stock, sauce, or custard Baked products are often cooked covered to keep the moisture in the product Both baking and roasting use a combination of convection and radiation to transfer heat to foods Some require a gentle heat so they are baked in a water bath, it regulates the heat so the product cooks very slowly. Baking in a water bath is also called baking au ban marie Moist heat methods Use liquid or steam in the cooking process At lower temperatures, moisture is more effective at heat transfer than air. Moist methods are best used for tougher cuts of meats and fibrous vegetables Poaching Cooking food in a liquid at relatively low temperature The liquid is often flavored Used for delicate products that might fall apart if cooked at higher temperatures The temperature range for poaching is 160 to 180 The poaching liquid transfers heat to the food by convection A properly poached product maintains its shape and delicate texture Two distinct techniques: Shallow poaching: poaching in a small amount of liquid that is often used to make a sauce after the poaching Deep poaching: enough liquid is used to cover the product, not used to create a sauce used for items such as eggs, whole fish, large cuts of poultry Simmering Cooks food in liquid at a temperature just below boiling, the proper temperature for simmering is 185 to 205 Temperature range is important for lower temperatures are not hot enough to break down connective tissues. Temperatures above 205 toughen proteins and make the cooking liquid cloudy It is used to make stocks and broths as well as cooking tough cuts of meat and poultry Boiling Is cooking in a liquid at its highest possible temperature. At sea level water boils at 212 degrees Fahrenheit Boiling liquids move rapidly creating a vigorous rolling motion and large bubbles Transferring heat through convection Steaming Is a moist method that cooks food products by surrounding it with steam vapor Steam is hotter than boiling water Steaming may be done in a steamer or steam oven Pressure steamers use a tightly sealed compartment with pressurized steam for greater heat transfer Combination methods Braising: combines the process of browning and simmering First the food is browned on all sides, in a small amount of fat then liquid is added and then it is simmered Braising has the ability to tenderize tough cuts of meat or poultry like simmering and it also has the rich flavor and color of sautéed items. The first process is done on the stovetop over high heat, then it can be covered and can be finished of on the stovetop or in the oven. Stewing: Stewing the vegetables or ingredients are cut into smaller pieces. Either the braising or simmering technique can be used to make a stew The ingredients for stew cook in enough liquid for them to float freely during the cooking process