This video will help a student to learn basic cooking principle thereby enhancing basic knowledge in planning a therapeutic diet.
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Language: en
Added: Nov 30, 2020
Slides: 60 pages
Slide Content
cooking
Purposes of cooking
To improve the appearance,flavorand taste of food and also
helps to develop, blend or alterflavors
To bring about structural changes in food. Meatfibersare
tenderized and the cellulose in vegetables and fruits is
softened so that they are easier to chew and digest
To stimulate the appetite and the digestive juices. It gives
food an attractive appearance, aroma and taste
To improve the keeping quality of food. It destroys some of
the harmful micro-organisms such as yeasts,and bacteria
that are naturally present
Principles of cooking
Heat is the most important factor behind cooking.
When food is cooked, it destroys the micro organisms and
makes food easier to ingest and digest.
BASIC COOKING PRINCIPLES
Effects of heat on food
Foods are composed of:
Carbohydrates
Fats
Proteins
Water
Minerals, Vitamins & Pigments
BASIC COOKING PRINCIPLES
CARBOHYDRATES
oStarches and sugars are both carbohydrates found in:
fruits, vegetables, grains, beans and nuts. Meats and
fish also contain a small amount
oTwo most important changes caused by cooking:
Caramelization
Gelatinization
Caramelization
oBrowning of sugars (browning vegetables and golden
colour of bread crust)
Gelatinization
oStarches absorb water and swell (thickening sauces)
BASIC COOKING PRINCIPLES
Fat Facts
Present in:
Meats, poultry, fish
Eggs, milk products
Nuts and whole grains
Fruits and vegetables
Break down when heated
Smoke when they become hot enough
Higher smoke point fats are good for deep frying
BASIC COOKING PRINCIPLES
Types of Heat Transfer
Conduction
Convection
Radiation
BASIC COOKING PRINCIPLES
The science of heat…
Cooking is the transfer of heat energy from some source
to the food
Cooking Methods
Moist Heat
Poach, simmer, boil
Cooking in water or seasoned,
flavored liquid
Steam
Expose foods directly
to steam
Braise
Cooked covered in a small
amount of liquid
Boiling
Cooked with enough water
over fire
Stewing
Food is cooked using a lot of liquid. Different kinds of
vegetables or meat are chopped, diced or cubed and added
to the pot. The liquid is slightly thickened
The only disadvantage is that some of the vegetables
might be overcooked and thus the nutrient content
becomes much less.
Sauté
To cook quickly in a small amount of fat
Preheat the pan
Do not overcrowd the pan
Meats are sometimes dusted with flour first
Pan is deglazed with a liquid after sautéing to dissolve
brown bits of food on the pan bottom
Pan-Fry
To cook in a moderate amount of fat in a pan over
moderate heat
Similar to sauté, but more fat is used
Usually done over lower heat
Amount of fat depends on food being cooked
Food is normally turned at least once
Deep-Fry
To cook submerged in hot fat
Barbequing
It is most suitable to cooking meat cutlets, fish or chicken
pieces.
The food is usually marinated with spices and tenderizers
(for meat cuts) for sometime before it is cooked.
With this method of cooking, a sheet of metal with stands
is heated up and oil is used to cook the food.
A sufficient amount of oil is heated up and food is added.
The food is then turned over a couple of times before it is
dished out.
Basting
This method of cooking is usually associated with
roasting.
The juice or liquid that comes out of the meat being
cooked is spooned over the roast frequently while it is
being roasted.
The outer part of the meat is moistened frequently during
the cooking process with the juice that is being spooned
over.
Usually, the extra juice from the cooked meat is added to
a mixture to make the meat sauce.
Blanching
It is a cooking process wherein the food substance, usually
a vegetable or fruit, is plunged into boiling water,
removed after a brief, timed interval, and finally plunged
into iced water or placed under cold running water to halt
the cooking process.
Food is blanched :-
to soften it
to partly or fully cook it
to remove a strong taste (for example of cabbage or
onions).
Dry Heat
Roast/Bake
To cook foods by surrounding them with hot, dry air
Cook uncovered
Meats cooked on a rack
Change position of product occasionally
Smoke roasting
Broil
To cook with radiant heat
from above
Used for tender items
Salamander
Itis a low-heat broiler
Grill
To cook with heat from below on an open grid
Griddling is done on a solid surface
Preservation of nutrients in cooking
Keep fruits and vegetables cool to prevent enzymes from
destroying vitamins.
Refrigerate food in airtight moisture-proof containers. The
loss of nutrients is slowed near freezing temperatures, at high
humidity, and less air contact.
Avoid trimming and cutting fruits and vegetables into
small pieces.
The greater surface area allows oxygen to break down
vitamins faster.
The outer leaves of all greens and under the skins of fruits
and vegetables, such as potatoes, carrots and apples, have
more nutrients than the inner portion
Microwaving cooking, steaming, or using a pan or wok
with very small amounts of water and a tight-fitting lid are
best.
More nutrients are retained when there is less contact
with water and a shorter cooking time with less exposure
to heat.
Cook fruits and vegetables with their skins on
Minimize reheating food.
Do not add baking soda to enhance a vegetable’s green
color. Alkaline products destroy vitamins.
Store canned goods in a cool place and serve any liquid
packed with the food. If you don’t need all the liquid to
cook the food, reserve the remainder for soup stock.
Keep milk refrigerated and tightly capped, away from
strong light.
Riboflavin is very sensitive to direct light.
Cook vegetables in a minimum amount of water or to use
the cooking water in soups and gravies.
Boiling rice in excess water and discarding the gruel
(kanjee)also results in loss of some amount of minerals
and vitamins.
Food storage
Freezers and thawing food
Freezer temperature should be maintained below 0°F.
Food should never be thawed at room temperature, this
increases the risk of bacterial and fungal growth and
accordingly the risk of food poisoning.
Once thawed, food should be used and never refrozen.
Frozen food should be thawed using the following
methods:-
Microwave oven
During cooking
In cold water (place food in watertight, plastic bag;
change water every 30 minutes)
Throw out foods that have been warmer than 40 °F for
more than 2 hours.
If there is any doubt at all about the length of time the
food has been defrosted at room temperature, it should be
thrown out
Refrigeration
Refrigerators should be set to maintain a temperature of
40 °F or below.
Storing oils and fats
Oils and fats can begin to go rancid quickly when not
stored safely.
Rancid cooking oils and fats do not often smell rancid
until well after they have spoiled.
Oxygen, light and heat all contribute to cooking oils
becoming rancid.
To help preserve oils from rancidification, they should be
refrigerated once opened.
Unopened oils can have a storage life of up to one year,
but some types have a shorter shelf-life even when
unopened (such as sesame
Vegetables
The guidelines vary for safe storage of vegetables under
dry conditions (without refrigerating or freezing).
This is because different vegetables have different
characteristics, for example, tomatoes contain a lot of
water, while root vegetablessuch as carrots and potatoes
contain less.
Many cultures have developed innovative ways of
preserving vegetables so that they can be stored for
several months between harvest seasons.
Techniques include pickling, home canning, food
dehydration, or storage in a root cellar.
Many factors affect the amount of time that a vegetable
can be kept in dry storage, as well as the temperature
needed to preserve its usefulness. The following guideline
shows the required dry storage conditions:
Cool and dry: onion
Cool and moist: root vegetable, potato, cabbage
Warm and dry: winter squash, pumpkin, sweet potatoes,
dried hot peppers