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

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Microorganisms are destroyed
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Most bacteria, fungi, and molds are killed by temperatures above
135
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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

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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
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Many starches must be heated in order for the thickening process to take place
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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
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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
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Monitoring timing and temperature is essential to achieve the
proper degree of doneness
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Things that happen if food is overcooked:
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Texture is destroyed and foods become mushy and disintegrate, or
tough and stringy

Proteins will curdle or toughen
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Moisture is lost

Sugars burn causing a bitter taste
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Green vegetables loose color
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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
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Conduction:

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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:
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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
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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
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Sautéing is traditionally done in a sauteuse, and it can also be done in
a griddle or in a wok
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Meat, poultry, seafood, vegetables, and starches can all be sautéed
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Sautéing transfers heat through conduction
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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
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Uses hot fat to cook a food item
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It cooks the food in enough hot fat to cover it halfway
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The food is turned during the cooking process in order to
cook the food completely
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May also be called shallow fat frying
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Large or thick pieces of meat, fish or poultry can be pan
fried
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Heat is transferred through conduction
Deep frying

Is a method that cooks food in enough fat to fully cover
them
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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
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Most deep fried foods are coated with flour, breading, or
batter before being fried
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This method transfers heat by convection
Grilling

Cooking method that uses radiation from a heat source
located below the food
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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
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It produces a robust flavor and is a healthy way to cook
Broiling
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Uses radiation from a heat source located above
the food
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Often used as a finishing process to brown cooked
foods
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Gratiner means to brown a foods product
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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
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Today it is mostly done in the oven
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Cooks food by surrounding it with hot air, during cooking
the food is uncovered so the moisture released can
evaporate
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The product to be roasted is placed on a rack so air can
circulate evenly on all sides
Baking
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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
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The temperature range for poaching is 160 to 180
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The poaching liquid transfers heat to the food by convection

A properly poached product maintains its shape and delicate texture
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Two distinct techniques:
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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
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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
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Steaming may be done in a steamer or steam oven
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Pressure steamers use a tightly sealed compartment with
pressurized steam for greater heat transfer
Combination methods
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Braising: combines the process of browning and simmering
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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:
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Stewing the vegetables or ingredients are cut into smaller
pieces.
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Either the braising or simmering technique can be used to
make a stew
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The ingredients for stew cook in enough liquid for them to
float freely during the cooking process