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Basic Cooking Methods Heat and Food • Effects of Heat on Food – Food are composed of proteins, fats, carbohydrates, and water, plus small amounts of other compounds such as minerals, vitamins and pigments (coloring agents), and flavor elements. • Carbohydrates – Starches and sugars are carbohydrates. – There are two important changes in carbohydrates » Caramelization- is the browning of sugars. » Gelatinization occurs when starches absorb water and swell. Heat and Food • Fruit and Vegetables Fiber – Fiber is the name for a group of complex substances that give structure and firmness to plants. » Fiber can not be digested. – The softens of fruits and vegetables in cooking is, in part breaking down the fiber – Sugar makes fiber firmer. Fruit cooked with sugars keep its shape better than cooked with out sugar. – Baking soda( and other alkalis) makes the fiber softer. » Vegetables should not be cooked with baking soda because they become mushy. • Proteins – Protein is the major component of meats, poultry, fish, eggs, milk, and milk products. – Coagulation. Proteins consist of long chains of components called amino acids. These normally form tight coils. As proteins are heated, the coils gradually unwind, the protein is then called denatured. Heat and Foods • Proteins contd. – The important fact about denaturing is that when a protein coils unwind they become attracted to each other and form bonds which is coagulation. – Many protein foods such as meats, contain small quantities of carbohydrates. When proteins are heated to about 310 degrees , the amino acids in the proteins chains react with carbohydrates molecules and undergo a complex chemical reactions. The result is that they turn brown and develop rich flavors, this is called the Mallard Reaction. – Connective Tissues are special proteins that are present in meats. – Acids, such as lemon juice, vinegar, and tomato products , do two things. » They speed coagulation » They help dissolve some connective tissue. Heat and Food • Fats – Fats are present in meats, poultry, fish, eggs, milk products, nuts, whole grains, and to a lesser extent, vegetables and fruits. • Fats are also important as cooking mediums, as for frying. – Fats can be either solid or liquid at room temperature. • Liquid fat are called oils. – When fats are heated, they begin to break down. • The temperature at which this happens is called the smoke point. – Many flavor compounds dissolve in fat, so fats are important carriers of flavor. Heat and Food • Minerals, Vitamins, Pigments, and Flavor Components – Minerals and vitamins are important to the nutritional quality of the food. – Some of these components are soluble in water, and others are soluble in fats. – Vitamins and pigment may also be destroyed by heat, by long cooking, and by other elements present during cooking. – It is important, then to select cooking methods that preserve, as much a possible, a food’s nutrients, taste, and appearance. Heat and Food • Water – Nearly al food contains water. – Water exists in three states, solid (ice), liquid, and gas( water vapor or steam). • At sea level, pure liquid water becomes solid or freezes at 32 degrees or below and turns into steam at 212 degrees. – Water can also turn from liquid to gas at lower temperatures. • When water turns to gas at any temperature, the process is called evaporation. – Many minerals and other compounds dissolve in water, so water can be a carrier of flavor and of nutritional value. – When water carries dissolved compounds, such as salt or sugar, its freezing points are lowered and its boiling point is raised. Heat Transfer • Conduction – Conduction occurs in two ways: • When heat moves directly from one item to something touching it – Ex. From the top of the range to a soup pot placed on it, from the pot to the broth inside, and from the broth to the solid food items in it. • When heat moves from one part of something to an adjacent part of the same item – Ex. From the exterior of a roast to the interior, or from a sauté pan to its handle. • Different materials conduct heat at different speeds. – Heat moves rapidly through copper, aluminum, more slowly in stainless steel, more slowly yet un glass and porcelain. Air is a poor conductor of heat. Heat Transfer • Convection – Convection occurs when heat is spread by the movement of air, steam, or liquid • There are two kinds of convection: – Natural » Hot liquids and gases rise while cooler ones sink. – Mechanical » In convection ovens and convections steamers, fans speed the circulation of heat Heat Transfer • Radiation – Radiation occurs when energy is transferred by waves from a source to the food. – The ways themselves are not actually heat energy but are changed into heat energy when they strike food being cooked. • There are two kinds of radiation are used in the kitchen: – Infrared » Boiling is the most familiar example of infrared cooking. – Microwave » In microwave cooking, the radiation generated by the oven penetrates partway in the food, where it agitates the molecules of water. Cooking Times • It takes time to heat a food to a desired temperature, the temperature at which a food is “done” ( meaning the desired changes have taken place). This is affect by three factors: – Cooking Temperature • This means the temperature of the air in the oven, the fat in the fryer, the surface of a griddle, or liquid in which a food is cooking. – The speed of heat transfer • Different cooking methods transfer heat at different rates. – An example is air is a poor conductor of heat, while steam is much more efficient. A jet of steam will easily burn your hand, but you can safely reach into an oven at 500 degrees. This is why it takes longer to bake potatoes than to steam. Cooking Times • Size, temperature, and individual characteristics of the food. – Example: a small roast beef will cook faster than a large one. – A chilled steak takes longer to broil than one at room temperature. Cooking Methods • Cooking methods are classified as moist heat or dry heat. – Moist heat methods • Are those in which the heat is conducted to the food products by water or water based liquids such as stocks and sauces, or by steam. – Dry heat methods • Are those in which the heat is conducted without moisture that is by hot air, hot metal, radiation or hot fat. Dry heat are broken into two categories: dry heat with fat and dry heat with fat. Moist Heat Methods • Poach, Simmer, and Boil – Poaching, simmering, and boiling all mean cooking a food in water or a seasoned or flavored liquid. The temperature of the liquid determines the method. • Boil – To boil means to cook in a liquid that is bubbling rapidly and is greatly agitated, the temperature of the liquid will f no higher. • Simmer – A simmer means to cook in a liquid that is bubbling gently at a temperature of a bout 185 to 205 degrees » Most food cooked in liquid are simmered. • Poach – Poaching means to cook in a liquid, usually a small amount, that is hot but not actually bubbling. Temperature is about 160 to 180 degrees. » Poaching is used to cook delicate foods, such as eggs and fish. Moist Heat Methods • Blanch – To blanch means to cook an item partially and briefly usually in water but sometimes by other methods. There are two ways to blanch. » Ex French fries are blanched in oil. » Place the food item in cold water, bring to a boil and simmer briefly. Cool by plunging into cold water. » Place the item un rapidly boiling water and return the water to the boil. Remove item and cool in cold water. – Steam • To steam means to cook foods by exposing them directly to steam. – In commercial cooking, steaming is usually done in a special steam cookers which are designed to accept standard-size pans. Steaming can also be done on a rack above boiling water. Cooking in a steamjacket kettle is not steaming because the steam does not actually touch the food. • The term steaming also refers to cooking an item tightly wrapped or in a covered pan so that it cooks in the steam for med by it s own moisture. En Papillote means wrapped in parchment paper or foil. Baked Potatoes that are wrapped in foil are actually steamed. Moist Heat Methods • Steam Contd. – Steam at normal pressure is 212 degrees, the same as boiling water, yet it carries much more heat than boiling water and cooks food rapidly. – A pressure streamer is a steam cooker that holds in a steam under pressure. – Steam is widely used for vegetables. It minimizes the dissolving away of nutrients that occurs when vegetables are boiled. Moist Heat Methods • Braise – To braise is to cook covered in a small amount of liquid, usually after preliminary browning. • In most case the liquid is served with the product as a sauce. • Braising and stewing are two different cooking methods. – Braising is used for large amounts of meat and stewing is for small cuts of meats. • Braise meats are usually browned first using a dry-heat method such as pan-frying. • Braising also refers to cooking some vegetables, such as lettuce, and cabbage, at a low temperature in a small amount of liquid with out first browning in fat • Foods being braise are usually not completely covered by the cooking liquid. • In some preparations, especially of poultry and fish, no liquid is added. • Braising maybe done on the range or in the oven. Oven braises have three major advantages: – Uniform cooking – Less attention required – Range space is free for other purposes Dry Heat Methods w/out fat • Roast and Bake – – To roast and to bake both mean to cook foods by surrounding them with hot, dry air, usually roasting in an oven. The term roasting usually applies to meat and poultry. Baking term is used for pastries and breads, vegetables. • • • • • • Broil – – – Roasting/baking is cooking uncovered is essential to roasting. Meat is usually roasted on a rack. When roasting in a conventional oven, the cook should allow for uneven temperatures by occasionally changing the position the position of the product. Barbeque means to cook with dry heat created by the burning of hardwood or the hot coals of this wood. Smoke-roasting is a procedure done on top of the stove in a closed container, using wood chips to make smoke. To broil mean to cook with radiant heat from above. Broiling is a rapid, high heat cooking method used mainly for tender meats, poultry, fish and a few vegetable items. • • • • • Turn heat on full. Use lower heat for larger, thicker items and for items to be cooked well done. Preheat the broiler Foods may be dipped into oil to prevent sticking and to minimizing drying. Turn foods over only once, to cook, to cook from both sides and to avoid unnecessary handling A low intensity broiler called the salamander is used for browning or melting the top of some items before service,. Dry Heat Methods w/out fat • Grill, Griddle, and Pan-Broil – They are all dry heat cooking methods that use heat from below. • Grilling is done over an open faced grid over heat source, which may be charcoal, an electric element, or gas heated element. The temperature is regulated by moving the items to hotter or cooler places on the grill. • Griddling is done on a solid cooking surface called griddle, with or without small mounts of fat to prevent sticking. The temperature is adjustable and much lower than on a grill. • Pan broiling is like griddling except that is done in a sauté pan or skillet instead if on a griddle surface. Fat must be poured off as it accumulates, or the process be comes pan frying. No liquid is added, and the pan is not covered, or it will steam. Dry Heat Methods using Fat • Sauté – Sauté means to cook quickly in a small amount of fat. There are two important principles. • Preheat the pan before adding the food to be sautéed. The food must be cooked at high heat or it will begin to simmer. • Do not overcrowd the pan. Doing so lowers the temperature too much and again the food begins to simmer in its own juices. – Meat to be sautéed are often dusted with flour to prevent sticking and to help achieve uniform browning. – After a food is sautéed, a liquid such as wine or stock is often swirled in the pan to dissolved browned bits of food sticking to the bottom which is called deglazing. – Stir frying is a variation of sautéing. • Pan Fry – Pan frying means to cook in a moderate amount of fat in a pan over moderate heat. • Pan frying is similar to sautéing except that more fat is used and the cooking time is longer. Dry Heat Methods with fats • Pan frying is usually done over lowered heat than sautéing because of the larger size of the pieces being cooked. • Most foods must be turned at least once for even cooking. Some larger foods may be removed from the pan and finished in the oven to prevent excessive surface browning. • Deep frying – To deep fry means to cook a food submerged in hot fat. Quality in a deep fried product is characterized by the following properties: • • • • • Minimum moisture fats absorption Minimum moisture loss Attractive golden color Crisp surface or coating No off flavors imparted by the frying fat. • Pressure Frying – This means deep frying in a special covered fryer that traps steam given off by the foods being cooked and increase the pressure inside the kettle.