Day 3• Baking Process

• Sensory properties of food

Words, Phrases, and Concepts

• Structure builder• Toughener• Tenderizer• Moistener• Drier• Air bubbles• Foams and

sponges• Hydration• Gluten

• Batters and doughs

• Oven spring• Starch granules• Starch

gelatinization• Maillard browning• Amylase• Retrogradation

Introduction

Three stages in baking process:

I. Mixing

II. Baking

III. Cooling

Introduction

Success in the bakeshop starts with a properly-balanced formula that contains a balance of:

• Tougheners and tenderizers.• Moisteners and driers.

Introduction

Structure builder – Also called toughener.– Examples: flour, eggs, cocoa powder,

cornstarch.• The proteins and starches in flour, eggs, and cocoa

powder are the actual structure builders.

– Holds the volume and shape of baked goods in place.

– Too much structure results in tough, hard baked goods.

Introduction

Tenderizer– Interferes with the formation of structure.– Examples: sugars and syrups, fats and oils,

leavening agents – Softens baked goods, making them easier to

bite into.– Too much tenderizing leads to crumbling or

collapse.

Introduction

Moistener– Thins out batters and doughs.– Examples:

• Water (moisture) and ingredients that contain water, including milk, eggs, cream, and syrups.

• Oil and melted fat.

Introduction

Drier– Opposite of moistener.– An ingredient that absorbs moisteners.Examples: flour, cornstarch, dry milk solids, cocoa

powder.

Stage I: Mixing

• Mixing method is important– Example: muffins mixed using muffin method

compared with creaming method

• Ingredient temperature is important– Example: pie pastry dough mixed with cold

vs. warm ingredients

Stage I: Mixing

As batters and doughs are mixed:• Ingredients are distributed evenly throughout.• Air bubbles are mixed in and reduced in size.

– Lightens batter/dough.– Provides for proper leavening and crumb formation.

note: batters/doughs are considered foams

because air bubbles are trapped.

Stage I: Mixing

As batters and doughs are mixed (cont.):• Large solid particles are worn down, layer by

layer, into smaller ones.– Allows them to dissolve or to hydrate faster.

• Fats/oils break into small chunks or droplets.

Stage I: Mixing

Role of water in mixing:• Dissolves small molecules.

– Activates them.– Examples: sugar crystals, baking powder.

• Hydrates large molecules and particles.– Hydration: layers of water surround large molecules

(driers), swelling and suspending them.– Activates them.– Example: formation of gluten.

Stage I: Mixing

Role of water in mixing (cont.):• Hydrates and activates yeast.• Adjusts batter/dough temperature.

Example: bread dough.

• Adjusts batter/dough consistency.– Batters are high in moisture; thin and pourable.– Doughs are low in moisture; thick and moldable.

Stage I: MixingMany ingredients are significant sources of water in the bakeshop.

Stage II: Baking

• During baking: – Heat is slowly conducted from the outside in.– Heat transforms batter/dough from a foam

that traps air bubbles to a porous sponge that does not.

• Term sponge is used whether product has a springy, spongy texture or not.

Stage II: Baking

Crumb, or grain, of baked goods consists of air cells surrounded by porous cell walls.

Stage II: Baking

Baking involves at least eleven events.– Is complex.– Events occur concurrently and influence each

other.– Many would never occur at room temperature;

this is, heat is required.– Several have no upper limit; that is, they

continue for as long as baked good is in oven.Examples: protein coagulation, starch gelatinization, evaporation of gases.

Stage II: Baking

1. Fats Melt.• Most melt between 90º and 130ºF (30º–55ºC).• Results in:

• Increased volume, or rise: trapped steam and air expand.

– The later fats melt, the more rise.

• Increased tenderness: melted fats coat structure builders.

– The sooner fats melt, often the more tenderness.Example: oil and pie pastry dough.

• Thinned batters and doughs.Example: high-fat cookie dough and spread.

Stage II: Baking

2. Gases Form and Expand.• Starts at room temperature; continues until

about 170ºF (75ºC).• Three most important leavening gases: air,

steam, carbon dioxide.• Results in:

• Increased volume or rise: expanding gases push on cell walls.Example: Oven spring

• Increased tenderness: expanding gases thin cells walls, making them easier to bite.

Stage II: Baking

3. Microorganisms Die.• Microorganisms include: yeast, mold, bacteria,

viruses.• Most die at 135 –140ºF (55–60ºC).

• Depends on microorganism and amount of sugar or salt.

• Results in:• Fermentation stopping.• Safer food, since pathogenic bacteria are killed.

Examples of pathogens: Salmonella bacteria, hepatitis virus.

Stage II: Baking

4. Sugar Dissolves.• Heat of oven dissolves sugar that did not

dissolve during mixing.• Results in:

• Moistening, tenderizing, browning, sweetening.• That is, sugar now acts like sugar.

Thinned batters and doughs. Dissolved sugar pulls water from driers.

Note: other solutes that dissolve during baking include acid salts in baking powder

Stage II: Baking

5. Egg and Gluten Proteins Coagulate.• Starts at 140 –160ºF (60–70ºC).• Egg proteins:

• Unfold (denature) and bond, forming a network of stretched-out clusters of egg proteins.

• Heat dries out and stiffens the proteins.

• Results in formation of rigid structure that sets the final size and shape of baked goods.

Stage II: Baking

6. Starches Gelatinize.• Starts at 120 –140ºF (50–60ºC).• Starch granules, tightly-packed with starch

molecules, swell and soften.• Results in:

• Thickening of batter/dough.• Formation of rigid structure that sets the final

size and shape of baked goods.

• Besides heat, water is required.• Bread dough vs. cookie dough

Stage II: Baking

7. Gases Evaporate.• Starts at about 160ºF (72ºC).• Rigid cell walls rupture from pressure of

expanding gases; gases escape.• Results in:

• Formation of dry, hard (white) crust.• Weight loss.• Aroma loss.

Stage II: Baking

8. Caramelization and Maillard Browning Occur on Crust.• Begins at 300ºF (150ºC) and above.

• Temperature of crust rises only after water evaporation slows.

• Caramelization: breakdown of sugars.• Maillard browning: breakdown of sugars and

proteins together.• Results in:

• Brown color.• Baked flavors.

Stage II: Baking

9. Enzymes are Inactivated.• By about 160 –180ºF (70–80ºC).

• Below this temperature, rising oven temperatures increase enzyme activity.

• Enzymes are:• Proteins.• Biological catalysts; that is, they speed up

chemical reactions.• Denatured by heat.

• Example: amylase.

Stage II: Baking

10.Changes Occur to Nutrients.• Examples of nutrients: proteins, fats,

carbohydrates, vitamins, minerals.• Results in:

• Proteins and starches becoming more digestible.

• Destruction of certain vitamins (Vitamin C and thiamin).

Stage II: Baking11.Pectin Breaks Down.

• Pectin holds fruits together.

• Dissolves when heated.• Results in softened fruit.

Stage III: Cooling

• Carryover cooking continues until baked goods reach room temperature.

• Changes occur during cooling and continue during storage.– Changes occur even when baked good is

properly wrapped.

• Many changes result in firming of baked goods as they cool.– Best to cool products to 100ºF (38ºC) or

below before slicing.

Stage III: Cooling

Eight main changes:1. Gases contract; weak structure collapses.

• Example: soufflés

2. Fats resolidify.• Decrease in greasiness, but product could become

hard and waxy.

3. Sugars recrystallize.• Provides crunchy crust in low-moisture products.

4. Starch molecules bond and solidify.• Called retrogradation; major cause of staling.

Stage III: Cooling

Eight main changes (cont.):5. Proteins bond and solidify.

• Contributes to staling.

6. Moisture is redistributed within crumb.

7. Moisture moves from moist crumb to dry crust.• Crust loses crispness; can become tough and

rubbery.

8. Flavors evaporate or become trapped by starches.• Brief reheating in oven recovers some lost flavor.

Words, Phrases, and Concepts

• Sensory perception• Sensory evaluation• Hue• Opacity• Sheen• Flavor• Umami

• Chemoreceptor• Orthonasal/retronasal• Astringency• Trigeminal effect• Mouthfeel

Introduction

Sensory perception:– Receptors on sense organs detect stimuli.

Examples of receptors:– Taste cells on taste buds in mouth.– Olfactory cells at top of nasal cavity.– Rods and cones in eyes.– Hair cells in inner ear.

– Brain interprets signals.

Introduction

Sensory properties:

• Appearance

• Flavor

• Texture

Introduction

Sensory evaluation:– Systematic and objective evaluation of the

sensory properties of foods.– Different from eating for enjoyment.– People vary in their abilities.Example: supertasters and nontasters

– Takes practice and concentration.

Appearance

We do “eat with our eyes.”– Sight is highly developed in humans.

Different aspects of appearance:– Color; also called hueExamples: red, blue, green

– Opacity; also called cloudiness• Contrasts with clarity or translucency

– Sheen; also called gloss• Contrasts with matte or dull.

Appearance

Perception of appearance is based on light that is: – Reflected (bounces off)– Transmitted (passes through)

Appearance

Our perception of appearance is affected by:

• The light source.

• The object itself.

• The surroundings.

AppearanceThe light source:

• If light source changes, appearance changes.– Includes differences in the type of lighting and

its intensity.

Example: bakeshop vs. dining room lighting.

Appearance

The object:

• Different objects absorb, reflect, and transmit light differently.– Some differences are chemical in nature.

• Ingredient or formula differences.Example: cake made with darker yolks.

• Bake time or temperature differences.– Chemical changes occur during baking.

Example: higher heat causes more browning.

Appearance

The object: • Different objects absorb, reflect, and

transmit light differently. – Some differences are physical in nature.

• Differences in air incorporation Examples: batters and egg whites.

• Differences in surface smoothnessExample: sugar crystal size in fondant.

Appearance

The surroundings:

• Can influence our perception of an object.

• A type of optical illusion.Example: white cake on white plate and on

black cake.

Flavor

• More important than appearance and texture to customers.

• Also called taste.• Three components:

– Basic tastes– Smell– Trigeminal effects.

• Chemical in nature.– Flavor molecules must interact with and excite chemoreceptors on sense organs.

Flavor

Basic tastes:• Sweet, salty, sour, bitter, umami.• Perception of certain flavor molecules: sugars,

salts, acids, caffeine, etc.• Perceived by chemoreceptors: taste cells on

taste buds.

Flavor

Basic tastes:• Requires saliva to carry flavor molecules to taste

cells in crevices in mouth.

Flavor

Do not confuse sourness with bitterness or astringency.

• Sourness is immediate and causes salivation.Examples: pickles, yogurt, buttermilk

• Bitterness is often delayed and lingers.Examples: unsweetened chocolate, black coffee

• Astringency is often delayed and causes drying; makes tongue feel rough.

Examples: strong black tea and grape skins

Flavor

Umami:– Fifth basic taste.– Means tastiness or savoriness in Japanese.– Important in savory items only: quiche,

focaccia, pizza.

Flavor

Smell:– Also called aroma or olfaction.– More complex than basic tastes.

• Humans can differentiate thousands of different smells.

• Most smells consist of hundreds of separate chemicals.

– Chemoreceptors: olfactory cells at top of nasal cavity.

FlavorSmell:

– Aroma molecules must evaporate to reach the olfactory cells.

– Two pathways: orthonasal and retronasal.

Flavor

Trigeminal effects:– Pungency of ginger– Burn of cinnamon– Cooling of mint– Heat of hot

peppers– Tingling of carbon

dioxide– Sting of alcohol

Flavor

Trigeminal effects are also called:– Chemical feeling factors– Pungency– Chemical irritation– Chemosensory irritation– Chemesthesis

Flavor

Trigeminal effects:– Chemoreceptors: free nerve endings just

beneath surface of skin.– Flavor molecule must be absorbed through

skin.

Flavor

Factors affecting flavor:– Nature of ingredient.Example: sugar and high-intensity sweeteners

– Product temperature.Example: sweetness, saltiness and temperature

– Product texture and consistency.Example: thin vs. thick liquids.

Flavor

Factors affecting flavor (cont.):– Presence of other flavors.Example: sugar and acid

– Fat content.Example: low-fat and fat-free foods

Texture

Examples of texture terms:

– Hard– Tough– Chewy– Crumbly, short, or mealy– Thick– Springy– Chalky– Moist– Dry

– Soft– Tender– Gummy– Brittle– Thin– Spongy– Gritty– Pulpy– Smooth

Texture

• Like flavor, is complex.• Appearance hints at texture• Evaluated by tasting and determining how

food:– Feels against the soft tissues of the mouth.

• Typically called mouthfeel

– Responds to squeezing, biting, chewing, etc.– Responds to heat of mouth– Sounds

Lab

• Taste bud test

• Gr 1: Muffins- creaming

• Gr 2: Muffins- 1 stage

Lab

• Gr 3 and 4:

• Poach eggs- Add vinegar to water

• Bring water to boil- Reduce to simmer- Swirl- add egg

• Gr 3- 30 sec. Gr 3- 1 min

• Gr 4- 1.5 min., Gr 4- 2 min.