Chapter 4 : Basic cooking principle & food science

Basic Cooking Principle and

Chapter 4

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Principle and Food Science

อาจารยปวิธ ตันสกุลสาขาวิชาอุตสาหกรรมทองเที่ยวสํานักวชิาการจัดการ มหาวทิยาลัยวลัยลักษณโทร. 2225 email: [email protected]

Outline – Basic Cooking Principle 1. Heat and Food

� Effect of Heat on Foods� Heat Transfer� Heat Management

2. Cooking Methods� Moist-Heat Methods

By Aj. Pavit Tansakul WMS : Tourism Industry 2

� Moist-Heat Methods� Dry-Heat Methods� Combine Methods

3. Building Flavor� Building Flavor Profile � Seasoning and flavoring ingredients� Using Herbs and Spices

Heat and Food

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Heat and Food

Heat and Food• To cook food means to heat it in order to

make certain changes in it. Skillful cooks know exactly what changes they want to make and what they have to do to get them right.

• To learn these cooking skills, it is important

By Aj. Pavit Tansakul WMS : Tourism Industry

• To learn these cooking skills, it is important for you to know why foods behave as they do when heated. For this, you have to study the theory.

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What is Heat?What is Heat?

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What is Heat?• Heat is a form of energy associated with the motion of atoms

or molecules. When a substance absorbs heat, its molecules move faster.

• In liquids and gases, the molecules move more quickly from place to place and bounce off each other more frequently.


place to place and bounce off each other more frequently. • In solids, the molecules stay mostly in place, but they vibrate

with more energy. • Temperature can be defined as a measure of this molecular

activity. The higher the temperature, the faster the molecules are moving.

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What is Heat?• When fast-moving molecules in hot substances

come in contact with slower moleculesin cold substances, the fast molecules bump into the slower ones and transfer some of their energy, making the slower molecules


their energy, making the slower molecules move faster, or heat up.

• Thus, as heat is transferred the hot substance loses energy and the colder substance gains energy.

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What is Heat?• The moving molecules in a liquid such as

water sometimes move to the surface withenough energy to break through and escape to become a gas. This is called evaporation.

• When the molecules in the liquid move faster,


• When the molecules in the liquid move faster, more of them can escape in a shorter time.This is why hot water evaporates more quickly than cold water.

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What is Heat?• When we add enough heat to foods, the

molecules may move so fast the structure of the food changes.

• For example, sucrose (regular sugar) may break apart and form new molecules that happen to


apart and form new molecules that happen to have a brown color and the taste of caramel. Or protein molecules may break apart and reform with a different structure. Creating these molecular changes is called cooking.

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Effects of Heat on foods

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on foods

Effects of Heat on foods• Effects of Heat on foods

– Food are composed of proteins, fat, carbohydrates, and water, plus small amount of other compound such as vitamins, pigments, and flavor element.

– It is important to understand how these


– It is important to understand how these components react when heated or mixed with other foods.

– In other words, when you know why foods behave as they do, you can understand how to get them to behave as you want them to.

Effects of Heat on Foods1. Carbohydrates2. Fruit and Vegetable Fiber3. Proteins4. Fats


4. Fats5. Mineral, Vitamins,

Pigment, and Flavor Components

6. Water

1. Carbohydrates• Starches and Sugar are carbohydrates, They found

in fruits, vegetables, grain, bean, meat and fish.• For the cook, the two most important changes in

carbohydrates caused by heat are

caramelization and gelatinization.


caramelization and gelatinization.

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1. Carbohydrates• Caramelization is the browning

of sugars. The browning of saut้ed vegetables andthe golden color of bread crust are forms of caramelization.

• Gelatinization occurs when


• Gelatinization occurs when starches absorb water and swell. This is a major principlein the thickening of sauces and in the production of breads and pastries.

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2. Fruit and Vegetable Fiber1. Fiber is the name for a group of complex substances

that give structure and firmness to plants. Fiber cannot be digested.


2. Fruit and Vegetable Fiber2. The softening of fruits and vegetables in cooking is,

in part, the breaking down of fiber. 3. Sugar makes fiber firmer. Fruit cooked with sugar

keeps its shape better than fruit cooked without sugar.

4. Baking soda (and other alkalis) makes fiber softer.


4. Baking soda (and other alkalis) makes fiber softer. Vegetables should not be cooked with baking soda because they become mushy and lose vitamins.

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3. Proteins• Proteins consist of long chains of

components called amino acids. • These chains normally form tight

coils. • As proteins are heated, the coils


• As proteins are heated, the coils gradually unwind.

• At this point, the protein is said to be denatured.

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3. Proteins• For the cook, the

important fact about denaturing is that, when the protein coils unwind, they become


unwind, they become attracted to each other and form bonds. This bonding is called coagulation.

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3. Proteins• The coagulated proteins form a solid network of bonds

and become firm. As the temperature increases, the proteins shrink, become firmer, and lose more moisture.

• Exposure of proteins to excessive heat toughens them and makes them dry.


and makes them dry. • Most proteins complete coagulation or cooked at 71O–

85OC

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3. Proteins• Many protein foods, such as meats, contain small

quantities of carbohydrate. • When proteins are heated to about 154OC, the amino

acids in the protein chains react with the carbohydrate molecules and undergo a complex chemical reaction.


chemical reaction. • The result is that they turn brown and develop richer

flavors. This reaction is called the Maillard reaction. • It is what happens when meat browns

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3. Proteins• Connective tissues are special proteins

present in meats. • Meats with a great deal of connective tissue

are tough, but some connective tissues are dissolved when cooked


dissolved when cooked slowly with moisture. Cooking tough meats properly, therefore, makes them more tender.

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3. Proteins• Acids, such as lemon juice, vinegar, and

tomato products, have two effects on proteins:• They speed coagulation.• They help dissolve some connective tissues.


4. Fats• Fats are present in

meats, poultry, fish, eggs, milk products, nuts, whole grains, and, to a lesser extent,


to a lesser extent, vegetables and fruits. Fats are also important as cooking mediums, as for frying

•

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4. Fats• Fats can be either

solid or liquid at room temperature.

• Liquid fats are called oils. When solid fats


oils. When solid fats are heated, they melt, or change from solid to liquid. The melting point of solid fats varies.

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4. Fats• When fats are heated, they begin to break

down. When hot enough, they deterioraterapidly and begin to smoke. The temperature at which this happens is called the smoke point, and it varies by type of fat.


point, and it varies by type of fat. • A stable fat—one with a high smoke point—is

an important consideration in deep-fat frying.

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5. Minerals, Vitamins, Pigment and Flavour

• Minerals and vitamins are important to the nutritional quality of the food.

• Pigments and flavor components are important to a food’s appearance and taste and maydetermine whether the food is appetizing


determine whether the food is appetizing enough to eat.

• So it is important to preserve all these elements.

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• Some of these components are soluble in water, and others are soluble in fats. All ofthese components may be leached out, or dissolved away, from foods during cooking.

• Vitamins and pigments may also be destroyed


• Vitamins and pigments may also be destroyed by heat, by long cooking, and by other elements present during cooking.

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• It is important, then, to select cooking methods that preserve, as much as possible, a


as possible, afood’s nutrients, taste, and appearance.

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6. Water• Water exists in three states:

1. solid (ice), 2. liquid, and 3. gas (water vapor or steam).

• At sea level, pure liquid water becomes solid, or


• At sea level, pure liquid water becomes solid, or freezes, at 0OC and turns to steam at 100OC

• When water molecules turn to steam and energetically escape into the atmosphere, water is said to be boiling. (boiling point at 100OC)

•

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6. Water• Water can also turn

from liquid to gas at lower temperatures. When water turns to gas at any


gas at any temperature, the process is called evaporation

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6. Water• Evaporation occurs more

slowly the lower the temperature is.

• Evaporation is responsible for the drying of foods.


for the drying of foods. • The drying of food

surfaces as they are cooked enables them to be browned.

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Heat TransferHeat Transfer

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Heat Transfer• In order for food to be cooked, heat must be

transferred from a heat source (such as a gasflame or an electric element) to and through the food.

• Understanding the ways in which heat is


• Understanding the ways in which heat is transferred and the speed at which it is transferred helps the cook control the cookingprocess.

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Heat Transfer • Heat is transferred in three ways:

1. Conduction2. Convection3. Radiation


3. Radiation

• It is important to remember that, during a cooking process, more than one of these methods of transfer may be happening at the same time

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CONDUCTION



1. Conduction1.1 When heat moves directly from one item to

something touching it—for example, fromthe 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.


the broth to the solid food items in it.

1. Conduction1.2 When heat moves from one part of something

to an adjacent part of the same item—forexample, from the exterior of a roast to the interior, or from a saute pan to its handle.


1. Conduction• Different materials conduct heat at different

speeds. • Heat moves rapidly through copper and

aluminum, more slowly in stainless steel, more slowly yet in glass and porcelain.


slowly yet in glass and porcelain. • Air is a poor conductor of heat.

CONVECTION


2. Convection• Convection occurs when

heat is spread by the movement of air, steam, or liquid (including hot fat). There are two kinds of


There are two kinds of convection:1. Natural 2. Mechanical


2.1 Natural • Hot liquids and gases rise, while cooler ones

sink. Thus, in any oven, kettle of liquid, ordeep-fat fryer a constant, natural circulation distributes heat.


2.2 Mechanical • In convection ovens

and convection steamers, fans speed the circulation of heat. Thus,


Thus,heat is transferred more quickly to the food, and the food cooks faster.

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2.2 Mechanical • Stirring is a form of

mechanical convection. Thick liquids cannot circulate as quickly as thin ones, so the rate


thin ones, so the rate of natural convection is slower.

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2. Convection• Convection is the process that carries the

heat from the heat source to the food. • Once the carrier of the heat (air or liquid)

comes in contact with the food, the heat is transferred from the carrier to the food by


transferred from the carrier to the food by conduction.

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RADIATION


3. Radiation • Radiation occurs when energy is

transferred by waves from a source to the food.

• The waves themselves are not actually heat energy but are changed into heat energy when they strike


into heat energy when they strike the food being cooked.

• Two kinds of radiation are used in the kitchen:1. Infrared2. Microwave

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3.1 Infrared• Broiling is the most familiar example of

infrared cooking. In a broiler, an electric element or a ceramic element heated by a gas flame becomes so hot it gives off infrared radiation, which cooks the food. High-intensity


radiation, which cooks the food. High-intensity infrared ovens are designed to heat food rapidly

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3.2 Microwave• In microwave cooking,

the radiation generated by the oven penetrates partway into the food, where it agitates the


where it agitates the molecules of water. The friction this agitation causes creates heat, which cooks the food.

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3.2 Microwave• Because microwave radiation affects only

water molecules, a completely waterlessmaterial will not heat in a microwave oven. Plates become hot only when heat is conducted to them by hot foods.


conducted to them by hot foods.• Because most microwaves penetrate no more

than about 2 inches (50 mm) into foods, heat is transferred to the center of large pieces of food by conduction, just as in roasting.

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Heat ManagementHeat Management

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Heat Management• Final temperature we cook

food• Rare meats & Fish = 49OC• Crisp Exterior = 200OC• Managing the heat to cook


• Managing the heat to cook foods to the desired degree is an important partof cooking.

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Doneness & Cooking Times• We say a food is “DONE” when two thing have

happened1. The interior temperature has risen to the

desired degree2. The desired changes have taken place in


2. The desired changes have taken place in the food

• Standards of doneness are different for every type of food and for every cooking method

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Doneness & Cooking Times• The time it takes to achieve doneness is

affected by three factors:1. Cooking Temperature2. The Speed of heat transfer3. Size, Temperature, and


3. Size, Temperature, and individual characteristic of the food.

Controlling Heat• To control cooking, we must control how heat

is transferred. • The kitchen contains dozens of kinds of heat

sources as well as a great array of pots, pans, and other cooking tools, Controlling cooking


and other cooking tools, Controlling cooking with so many options is a skill a cook gains with experience, by performing cooking tasks over and over

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How to Boil Water• Covering the POT• To bring water to a boil on a cooktop, we apply

heat to the bottom of a pot containing the water.• The heat is transferred to the water, raising its

temperature. Some of this heat energy quickly


temperature. Some of this heat energy quickly escapes from the top of the pot.

• If the pot is covered, much of the heat is trapped inside, and the water comes to a boil much more quickly.

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How to Boil Water• Although covering pots is a more efficient use of energy,

sometimes you must keep them uncovered:• When evaporation is desired. In many cooking operations, one

of the goals is to evaporate moisture to concentrate flavors or change textures. Keep the pot uncovered to speed evaporation.

• When the contents must be visually monitored. In some cases,


• When the contents must be visually monitored. In some cases, you must keep an eye on the food as it simmers or boils, if only to make sure it continues to simmer at the proper rate, not too fast or too slow.

• When green vegetables are cooked. Plant acids that destroy green pigments must beallowed to escape

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Boiling Oil


Controlling the Heat• When water is boiling, any additional heat is used to turn

water to steam, which then carries the heat away.• No matter how high you turn the heat, the water can

never rise above 100C. • In other words, turning up the heat under a pot that is

already boiling is a waste of energy and does not


already boiling is a waste of energy and does not decrease cooking time.

• Furthermore, the increased agitation of rapidly boiling water does more damage to delicate foods. Remember, a rapid boil is no hotter than a slow boil.

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Cooking to the centre• Heat is transferred from the outside

of food to the inside by conduction. Conduction takes time, so cooking takes time.

1. Brown the exterior with high heat, then cook to doneness at


1. Brown the exterior with high heat, then cook to doneness at lower heat.

2. Cook to doneness at low heat, then brown the exterior with a quick blast of high heat.

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Cooking Methods

2Cooking Methods

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Cooking Methods

2.1 Moist-Heat Methodsare those in which the heat is conducted to the food product by water or water-based liquids such as stock and sauces, or by steam.

2.2 Dry-Heat Methodsare those in which the heat is conducted without


are those in which the heat is conducted without moisture—that is, by hot air, hot metal, radiation, or hot fat. We usually divide dry-heat methods into two categories: without fat and with fat.

2.3 Combination Methods Moist-Heat Methods & Dry-Heat Methods

Cooking Methods• Many other factors must be considered when

choosing cooking methods for meats, fish,and vegetables, such as the flavor and appearance imparted by browning, the flavor imparted by fats, and the firmness or delicacy


imparted by fats, and the firmness or delicacy of the product.

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2.1 Moist-Heat Methods

1. Poach, Simmer, Boil, BranchPoaching, simmering, and boiling all involve cooking a food in water or a seasoned or


food in water or a seasoned or flavored liquid.

The temperature of the liquid determines the method.

2.1 Moist-Heat Methods1.1 Boil• To boil means to cook in a liquid that is

bubbling rapidly and greatly agitated. Water boils 100C at sea level.

• No matter how high the burner is turned, the


• No matter how high the burner is turned, the temperature of the liquid will go no higher.

• Boiling is generally reserved for vegetables and starches. The high temperature toughens the proteins of meats, fish, and eggs, and the rapid bubbling breaks up delicate foods.

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BOIL


2.1 Moist-Heat Methods1.2 Simmer

To simmer means to cook in a liquid that is bubbling gently at a temperature of about


bubbling gently at a temperature of about 85-96OC

2.1 Moist-Heat Methods1.3 Poach

To poach means to cook in a liquid, usually a small amount, that is hot but not actuallybubbling at 71-82OC


bubbling at 71-82 C Poaching is used to cook delicate foods such as fish and eggs out of the shell

2.1 Moist-Heat Methods1.4 Blanch• To blanch means to cook an item partially and briefly,

usually in water but sometimesby other methods1. Place the item in cold water, bring to a boil, and simmer

briefly. Cool the item by plunging it into cold water.


briefly. Cool the item by plunging it into cold water.Purpose: to dissolve out blood, salt, or impurities from meats and bones.

2. Place the item in rapidly boiling water and return the water to the boil. Remove the item and cool in cold water.Purpose: to set the color and destroy harmful enzymes in vegetables, or to loosen the skins of tomatoes, peaches, and similar items for easier peeling.


2.1 Moist-Heat Methods

2. Steam• To steam means to cook

foods by exposing them directly to steam.

• The term steaming also


• The term steaming also refers to cooking an item tightly wrapped or in a covered pan so it cooks in the steam formed by its own moisture.

2.1 Moist-Heat Methods• This method is used in cooking items en

papillote, meaning “wrapped in parchment paper” (or foil).


2.1 Moist-Heat Methods• “Baked” potatoes wrapped in foil are actually

steamed.


2.1 Moist-Heat Methods• Steam at normal pressure is 100C, the same as

boiling water. However, it carries much more heat than boiling water and cooks foods very rapidly.

• Cooking times must be carefully controlled to


• Cooking times must be carefully controlled to avoid overcooking

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2.1 Moist-Heat Methods• A pressure steamer is

a steam cooker that holds in steam under pressure. The temperature of the


temperature of the steam then goes higher than 100C

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2.2 Dry-Heat Methods1. Roast and Bake• To roast and to bake both mean

to cook foods by surrounding them with hot, dry air, usually


them with hot, dry air, usuallyin an oven.

• Cooking on a spit in front of an open fire may also be considered roasting

2.2 Dry-Heat Methods

1. Roast and Bake (Cont.)• The term roasting usually

applies to meats and poultry.

• The term baking usually applies breads, pastries,


• The term baking usually applies breads, pastries, vegetables, and fish.

2.2 Dry-Heat Methods• A roast may be browned by another cooking

method, such as pan-frying or broiling,before being placed in the oven.

• This technique is most useful for small


• This technique is most useful for small poultry and small cuts of meat, which may not brown sufficiently in the oven due to their short roasting times.

2.2 Dry-Heat Methods• To barbecue means to cook

with dry heat created by the burning of hardwood or by the hot coals of this wood.

• In other words, barbecuing is


• In other words, barbecuing is a roasting or grilling technique requiring a wood fire.

2.2 Dry-Heat Methods2. Broil • To broil means to cook

with radiant heat from above

• Broiling is a rapid,


• Broiling is a rapid, high-heat cooking method used mainly for tender meats, poultry,fish, and a few vegetable items.

2.2 Dry-Heat Methods3. Grill, Griddle and Pan Broil

dry-heat cooking methods that use heat from below Grilling is done on an open grid over a heat source, which may be charcoal, an electricelement, or a gas-heated element.


element, or a gas-heated element. Griddling is done on a solid cooking surface called a griddle, with or without smallamounts of fat to prevent sticking. Pan-Broil s like griddling except it is done in a saut้ pan or skillet instead of on agriddle surface.


2.2 Dry-Heat Methods Using FAT4. SauteThe French word saute means “to jump,” referring to the action of small pieces of food tossed in a saut้ pan 5. Pan-Fry To pan-fry means to cook in a moderate amount of fat in a


To pan-fry means to cook in a moderate amount of fat in a pan over moderate heat 6. Deep-Fry To deep-fry means to cook a food submerged in hot fat. 175-190 OC

2.3 Combination Methods 1. Braise • To braise means to cook

covered in a small amount of liquid, usually after preliminary browning.


browning.• In almost all cases, the liquid is

served with the product as a sauce.

• usually not completely covered by the cooking liquid

2.3 Combination Methods

2. StewThe term braising is used for large cuts of meat, and stewing is used for smaller items.


stewing is used for smaller items. Stews are usually cooked in just enough liquid to cover them completely

Braises VS Stews



Summery of Cooking Terms1. Bake2. Barbecue3. Blanch4. Boil5. Braise6. Broil7. Deep-fry

13. Pan broil14. Pan fry15. Parcook16. Poach17. Reduce18. Roast19. Saut้


6. Broil7. Deep-fry8. Deglaze9. Fry10. Glaze11. Griddle12. Grill

18. Roast19. Saut้20. Sear21. Smoke22. Steam23. Stir-fry24. sweat

Building Flavor

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Building Flavor

3.1 Building Flavor Profiles• Food offer complex

experiences for the senses. When composing a new dish.

• A cook must first of all understand that more than just taste should be considered.


considered. • The senses of sight, smell,

taste, and touch all come into play.

• Consider how we perceive these characteristics of a dish:

Building Flavor Profiles• Appearance

(color, color contrast, shape, shine, arrangement)

• Aroma• Taste


• Taste• Mouth feel

(texture, moistness or dryness, softness or crispness and temperature)


Building Flavor Profiles• The flavors in a dish can be thought of as primary flavors

and supporting, or secondary,flavors.

• The primary flavors are the flavors of the main ingredients. For example, the primary flavors in Irish lamb stew are lamb, onions,


lamb stew are lamb, onions,leeks, and potatoes. These are the flavors that predominate

• Other flavors, which we can call supporting flavors, support and enhance the primary flavors of the main ingredients.

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General Concepts in Flavor Building• Every ingredient should have a purpose• Ingredients can work together by harmonizing

or by contrasting• When two ingredients contrast, be sure they

balance


balance• Consider not only the component of the single

recipe but also other items that will be served with it on the plate

CLASSIC FLAVORING COMBINATIONS


3.2 Seasoning and Flavoring Ingredients

• SeasoningEnhance the natural flavor of food

• Flavoring


• Flavoringadding new flavor to food and change the original flavor

Seasoning1. The most important time for seasoning liquid foods is at the end

of the cooking process.2. Salt and other seasonings are also added at the beginning of

cooking, particularly for larger pieces of food, when seasonings added at the end would not be absorbed or blended in but just sit on the surface.

3. Adding some of the seasoning during the cooking process aids in


3. Adding some of the seasoning during the cooking process aids in evaluating the flavor along the way.

4. Do not add much seasoning if it will be concentrated during cooking, as when a liquid is reduced.

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Flavoring• Flavoring ingredients can be added at the

beginning, middle, or end, depending on the cooking time, the cooking process, and the flavoring ingredient.


Flavoring1. Only a few flavorings can be added successfully at the

end of cooking. These include fresh (not dried) herbs, sherry or flamed brandy, and condiments like prepared mustard and Worcestershire sauce.

2. Most flavorings need heat to release their flavors and time for the flavors to blend. Whole spices take longest.


time for the flavors to blend. Whole spices take longest. Ground spices release flavors more quickly and thus don’t require as long a cooking time.

3. Too much cooking results in loss of flavor. Most flavors, whether in spices or in main ingredients, are volatile, which means they evaporate when heated. That is why you can smell food cooking.

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Common Seasoning & Flavoring ingredients1. Salt2. Pepper

(black, white, green)3. Lemon juice4. Fresh herbs5. Onion, garlic,

shallot, carrot, celery


5. Onion, garlic, shallot, carrot, celery

6. Whine, brandy7. Mustard8. Grated lemon,

grated orange9. MSG

3.3 Using Herb & Spices*** pls see the Kitchen Staple


Food Science BasicsFood Science Basics

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Food Science Basics• Understanding how food reacts under certain

conditions is essential becoming a professional chef.

• From creating flavorful dish to developing an innovative shortcut, chef face challenges everyday

• The Six basic principle of food science are as


• The Six basic principle of food science are as follows:

• Caramelization •Denaturation• Maillard Reaction • Coagulation• Gelatinization • Emulsification

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1. Effect of Heat on Starches and Sugars

• The two form of carbohydrates : SUGAR & STARCH

• When exposed to heat, sugar will first melt into a thick syrup.

Caramelization / Maillard Reaction / Gelatinization


first melt into a thick syrup.• As the temperature continues to rise,

the sugar syrup changes color, from clear to light yellow to brown

• This Browning process is called CARAMELIZATION => Caramel

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• Granulated white sugar • Melts at 160๐C• Caramelize at 170๐C



• In food that are not primarily sugar or starch, a different reaction, known as the MAILLARD REACTION

• The Maillard Reaction, is responsible for BROWNING.

Temperature > 149๐C


• The Maillard Reaction, is responsible for BROWNING.

• Involves SUGAR + AMINO ACIDS• When heated, react the chemical,

Resulting in a brown color and intense flavor and aroma

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It is this react that give

coffee, chocolate, baked

goods, roasted meat

much of their rich flavor

and color

Temperature > 149๐C


• Food cooked with Moist heat => NOT BROWN(Boiling, Steaming, Poaching, Stewing)


Poaching, Stewing)• Food cooked with

Dry-heat => WILL BROWN(Sautéing, Grilling, roasting)

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Maillard reaction

• The Maillard reaction (pronounced may-YAR) is a chemical reactionbetween an amino acidand a reducing sugar,


and a reducing sugar, usually requiring heat.

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• Starch, a complex carbohydrate, has powerful thickening properties.

• When starch is combined with water and heated, individual starch granules absorb the liquid and


granules absorb the liquid and swell.

• This process, known as GELATINIZATION, it what causes the liquid to thicken

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• Root-based Starches (potato and arrowroot)– Thicken at lower temperatures but – Break down more quickly

• Cereal-based Starches (Corn and Wheat)– Thicken at Higher temperature but


– Thicken at Higher temperature but– Break don more slowly

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2. Denaturing Proteins • Nature proteins are shaped like

coils or spring• When natural protein are

exposed to heat, salt, or acid, they DENATURE – the coin UNWIND


UNWIND• When food is cooked, some of its

proteins become denatured. • This is why boiled eggs become

hard and cooked meat becomes firm

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2. Denaturing Proteins• Denaturation is a process in which

proteins or nucleic acids lose their tertiary structure and secondary structure

• by application of some external stress or compound, such as a strong acid or base, a concentrated


strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), or heat.

• If proteins in a living cell are denatured, this results in disruption of cell activity and possibly cell death.

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2. Denaturing Proteins

• When protein denature, they tend to bond together, or COAGULATE, and from solid clumps (to change from a fluid into a thickened mass)

• Egg white, which changes from


• Egg white, which changes from transparent fluid to an solid

• As protein coagulate, they lose some of their CAPACITY TO HOLD WATER

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2. Denaturing Proteins

• That why protein-rich food give off moisture as they cook, even they are steamed or poached

• Some heat-induced denaturation is REVERSIBLE through cooling


is REVERSIBLE through cooling => Juice and Become Moisture

• Denature proteins are easier to digest than natural proteins

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3. Function of Cooking Fats• Fat provides an appealing visual element when

a food appear to be moist, creamy, fluffy, or shiny.


3. Function of Cooking Fats

• During Baking Process• Fat perform a multitude of chemical functions, such as tenderizing, leavening, aiding in moisture retention


aiding in moisture retention• During Cooking Process

• Fat transfer heat to food and prevent them from sticking

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3. Function of Cooking Fats• One important aspect of fat is ability to be

heated to relatively high temperatures without boiling otherwise breaking down.

• If heated to high temperature, fat will begin to breakdown, known as SMOKING POINT


to breakdown, known as SMOKING POINT• Vegetable Oils begin to smoke at 132๐C• Animal Fats begin to smoke at 191๐C

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4. Function of Water in Cooking

• Water is the primary substance in most food.

• Fruits and Vegetables contain up to 95 percent water, Raw meat is about


water, Raw meat is about 75 percent water

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• Water Freezes at 0๐C and Boiling at 100๐C lead to EVAPORATION, which make REDUCTION

• When salt and sugar is dissolved in water, the


• When salt and sugar is dissolved in water, the freezing point is LOWEREDand the Boiling point is RAISED

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• Pure water, which is neutral has a pH of SEVEN

• The pH of a solution affects the flavor,


affects the flavor, color, texture, and nutrition quality of foods

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5. Forming Emulsions

• An emulsion occurs when two substances that do not normally mix are forced into a mixture

• Under normal conditions, FAT and water DO NOT MIX, but these two


water DO NOT MIX, but these two are MOST common ingredients in culinary emulsions

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5. Forming Emulsions

• An emulsified vinaigrette is an example of an oil-in-vinegar emulsion.

• Temporary emulsions form quickly and require only the


quickly and require only the mechanical action of whipping, shaking, or stirring

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5. Forming Emulsions• To make an emulsion stable

enough to keep the oil in suspension, additional ingredients, known as EMULSIFIERS, are necessary to attract and hold together both


attract and hold together both oil and liquid

• Commonly used emulsifiers are Egg Yolks, Mustard, Natural starches in Garlic, Corn starch, Arrowroot are used

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Q&A

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Q&A