Bread & Pastries Flashcards
What are the key ingredients in dough?
- Yeast
- Flour
- Water
- Salt
What are the 3 categories of leaveners?
- Biological
- Chemical
- Vaporous
What is a biological leavening leavening agent?
Yeast
what was the first to leaven?
Sourdough
What is sourdough?
A collection of wild yeast and bacteria the fall into a glop of water and flour
When was yeast first recognized? By who?
1600-1800
- Von Leewonhoeks microscope
- Louis Pasteur
Yeast produces ____, which ferments ___
Zymase
Ferments sugar
What is the reaction that enzyme catalyzes?
Glucose -> Ethanol + CO2
What are the 3 basic functions of yeast?
- Co2 leavens dough
- Variety of by products contribute to the bread flavour
- fermentation process develops the dough
____ is Baker’s yeast used in break making
Saccharomyces Cerevisiae
Why is s. cerevisiae used in baking ?
- Good Co2 production
- Development of desirable flavour
- Adequate keeping qualities
What are the 3 kinds of yeast?
- compressed
- Active dry
- Instan yeast
What is compressed yeast?
- Marche Lobo yeast
- Fresh
- require refrigeration (perishable)
What is active dry yeast?
- Dehydrates
- Rehydrates in water at 43-46C
At a higher temp, active dry yeast is activated/inactivated?
Inactivated
At a lower temp, active dry yeast ___ into liquid, which __ bread dough
leaches cell contents into liquid
Softens
What is instant yeast?
Soluble and is added directly to dry ingredients
What is the optimal temp for yeast activity?
30-35C
What are some other optimal conditions for yeast activity?
- Hydration
- pH 4-6
- Food (sugar)
Under high osmotic pressure (salt/sugar concentration) yeast activity is (activated/inhibited)
inhibited
Yeast needs __
Glucose
What is “sugar” that we add to dough during baking?
Sucrose (glucose, fructose)
What is found in flour?
1-2% sucrose, starch
What does sucrose and starch break down into?
Sucrose breaks down into glucose, which undergoes fermentation to produce ethanol and CO2
Enzymes ___
hydrlyze larger chains
What reactions does a-flour amylases catalyze?
a-amylase: starch -> random smaller pieces
What reaction does b-flour amylase catalyst?
starch->maltose
What are the two predominant enzymes in baking?
1) Flour amylases (alpha and beta)
2) yeast (Maltase and Invertase)
What does the yeast maltase enzyme catalyze?
Maltose -> glucose + glucose
What does the yeasts enzyme Invertase catalyze?
sucrose -> glucose + fructose
Amylase enzymes catalyze a ___ reaction
Hydrolysis
What is the definition of the fermentation process?
The ABILITY of yeasts which are naturally found in AIR, WATER and LIVING ORGANISMS, to process CO2 through fermentation
Sugar is present in ____
Small and Large amounts
What is a small amount of sugar? what does it do?
< 8% weight of flour
Provides a readily available substrate for immediate gas production by yeast
What does a larger amount of sugar do? (3)
- Inhibits yeast activity
- Tenderizes gluten proteins
- Browning (maillard rxn)
What is the function of wheat flour? What proteins do they provide?
Provides glutenin and gliadin form which gluten is developed during hydration and mixing
Why is liquid necessary in bread?
to hydrate proteins and starch for gluten development
What is the most common liquid used in bread making?
Milk
Whys is milk the most utilized? (4)
- Adds nutrient
- Finer Texture
- Improves crust/crumb flavour and texture
- WHEY softens dough, decreases volume
Addition of milk in bread making may cause a soft dough and a decrease in volume due to the whey protein - how can this be avoided?
Milk can be scalded to denature the whey proteins
How much salt is added to flour?
<2% flours weigh
What are the 3 main functional properties of salt?
- Stabilizes yeast activity (slows activity)
- Changes rheological properties of dough (liquid/flow)
- Firming effect on gluten
how does salt have a firming effect on gluten? (2)
- Increase water gelding capacity of dough
- Increase mixing requirement of doiugh
Salt influences ___
dough FIRMNESS (think of how firm play dough is)
What is an optional ingredient in bread making?
Eggs
When fat is added, how much does it contribute in respect to weight of flour?
<3% weight of flour
What are the 4 functional properties of fat in flour?
- Increases loaf volume
- Gives a more uniform and tender crumb
- Improves slicing properties
- decrease staling
Name the 7 additives/dough conditioners (SOFA-ACE)
- Surface Active Agents
- Oxidizing Agents
- Fibers
- Antioxidants
- Antimolding Agents
- Ca2+/NH4+ salts
- Enzymes
What are the 2 surface active agents? What are 2 examples of each?
1) Dough conditioners: polyethylene monostearate & polysorbate 60
2) Dough softeners: (monoglycerides, sodium stearyl-2-lactate)
What does polysorbate 60 do?
Dough conditioner
Strengthens the gluten structure and improves its gas-retaining ability
What do monoglycerides do?
Dough softener
Increases shelf life of bread by retarding firming of crust
What are some examples of oxidizing agents? What do they do?
K+/Ca2+ bromates and iodate
-Set the structure of the protein network in dough
What are the 2 kinds of fibres?
Cellulose or bran
What are the 2 kinds of antioxidants?
BHA
BHT
What are 2 antimolding agents? What do they do?
Sodium and calcium propionate
Inhibit the growth of spore forming organisms
What are the 3 functions of calcium/ammonium salts?
- Supply nutrients
- buffering
- Ca2+ has firming effect on gluten
What are enzymes? What do they do?
Proteases improve dough handling and extensibility
In the italian crusty bread, what is the function of sodium sterol-2-lactylate?
Dough softener
In the Italian crusty bread, what is the function of malt extract ester of mono/di glycerides?
Malt extract: provide nutrients and enzymes to yeast (from barley)
Esters: dough softeners
What is the role of calcium sulphate? Calcium propionate? Calcium iodate?
Sulphate = strengthener Propionate = Inhibits mold growth Iodate = OA, sets protein structure
What are the 4 steps in breadmaking?
- Mixing and kneading
- Fermentation/rising
- Punching down
- Proofing
What is the result of the mixing and kneading stage?
Numerous cells of air are incorporated and development of the gluten structure in the doiugh
What is the result during fermentation/rising?What happens after?
Decrease on PH due to the production of CO2 and lactic acid.
After, gas vacuoles are formed.
What does punching down permit?
A uniform distribution of fas cells throughout he dough
What does proofing allow?
for the dough to rise in the pan after fermentation and before baking
From a scientific perspective, what is kneading?
Unfolds and alight the initially tables gluten molecules crosslinks by SULPHIDE bonds
What kind of bonds does gluten have?
Sulfide bonds
Describe the 3 steps in kneading
1) Doughs furthest edge is lifted up and folded towards nearest edge
2) The heels of both hands push firmly against the fold
3) dough is turned a quieter turn and process is repeated
Dough is __
developed my kneading
What causes the dough to rise in fermentation?
Carbon dioxide produced by yeast, and and enzyme and pH change takes effect
Optimum proofing cells are ….
Uniform, intact
Over proofing cells are ___
Lysed
What does over proofing do?
produces a low volume bread due to the the collapsing and escape of fermentation gases of the cells (lyse)
What happens during the first few minutes of baking> At what temp is yeast inactivated?
-Yeast activity stimulated -CO2
-Volum increases (oven spring)
yeast inactivated at ~60C
adequate volume dependant on the ability of the gluten mass to do what? 92)
- Expand
- Produce thin cell walls that hold up gas to the point of setting the structure
How is the brown colour of the crust formed?
- Mailard rxn
- Caramelization of sugar
Which of the following is a result of baking?
A) Changes in appearance, texture, flavour, aroma
B) Yeast killed
C) Protein coagulation
D) Starch swells & gelatinizes
E) Fat Melts and crumbs develop
F) All of the above
F) All of the above
After baking what two things happen?
1) starch is gelatinized
2) gas vacuoles ate dispersed throughout the structure
What is the flavour of bread from?
Volatile and nonvolatile substances produced during fermentation
What is staling?
Involves the amylopectin of starch to undergo retrogradation (crystallization)
Describe the path of amylose from fresh baked bread to stale bread,
Fresh: amylose and amylopectin swollen and randomly orientated
Cooling: Amylose aligns and crystallizes
Staling: Amylopectin realigns and reforms crystallites?
Can staling be reversed?
Yes, through heating which will allow for unaligning and recrystallization of amylopectin (amylose still aligned)
Simplest yeast bread is made from what 3 ingredients?
Flour, water and yeast
What are the two types of pastry?
Non laminatad
Laminated
What are some examples of non laminated pastries?
Pie, tarts, tartlets, brioche, choux
What are some examples of laminated pastry?
puff, quick, phyllo, croissant, danish
What are the two desirable characteristics of pastry?
Flakiness and tenderness
What does flakiness depend on?
An imperfect blend of fat and flour (degree of separation)
Name 3 ways fat is the major contributor of flakes in pastry
- Size of its parcticles
- firmness
- spreadable
Flakiness is measured by the __
size of its flakes
List the types of pastries (3) from flakiest to least flaky
Long flake > Short flake > Mealy
Scientifically, how does fat work in pastry?
The hydrophobic fat will not associate with the water vapour (steam) since it is hydrophilic, bouncing off the “walls” of the fat layers, puffing up,
Tenderness is maximized when ____
fat coats flour, preventing hydration of flour particles and therefore inhibiting gluten formation
The shortening power of fat is related to its degree of saturation (T/F)
FALSE, shortening power related to degree of unsaturation
The more unsaturated the fat the more (tender/dense) the pastry
more tender
Oil has a greater/lesser shortening power than butter or lard
greater bc its unsat
How many cups of fat/cup of flour in pastry?
1/4 to 1/3 cup
Name 5 things that develop gluten strands and decrease tenderness (SFPOL)
- too little shortening
- too much flour during rolling
- increasing protein content
- over manipulation
- increasing liquid
What two ingredients can be aded to pastry to toughen it?
Salt and water
Describe the classic pastry method
1) flour/salt sifted together
2) cold fat cut in (pastry blender)
3) Cold water sprinkles one TBSP at a time over the flour
4) Dough is well mixed, wrapped and refrigerated to chill the fat.
When mixing puff pastry, it is muted into __
2 separate mixtures
What are the 2 separate mixtures of puff pastry?
fat component (butter block) Dough
what is the fat/butter block?
- fat
- flour
- sat
- acid (vinegar)
what is the dough?
flour, salt, water, and a bit of fat
When making puff pastry, it is important to remember to do what?
Chill the fat
How does puff pastry appear when insufficiently filed? excessive folding?
Insufficient = large steam pockets/high volume Excessive = very small steam bookers and low volume
