Day 3 • Baking Process • Sensory properties of food
Dec 29, 2015
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
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 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 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