Lab 7: Baking 3 Flashcards
Why are aspartame acceptable for moderate use in diabetic or weight loss diets?
They do not affect the blood glucose levels
What happens when artificial sweeteners are exposed to high temperatures for long periods of time?
what artificial sweeteners were used in the lab when baking?
Some may lose their sweetness
Splenda and Sugar twin were used in the lab instead of Equal
What may occur when artificial sweeteners are used in baking?
the baked good may turn out dense, less tender, or it may not become brown or crispy.
What is stevia?
A herb, used as a sweetener in South America
How much sweeter is stevia than sugar?
300x
Reducing ___ of the sugar from the original recipe will yield good results
1/3
Fruit juices and concentrates and sugar free spreads may be used as a sweetener but what other sugar may they contain?
fructose
How can the nutritional value of bread be enhanced?
Add fruits, nuts, seeds, WW flour,
What is the enzyme that yeast produce in bread?
What is its purpose?
zymase
converts glucose and fructose into CO2, alcohol and other flavour components
What are the 3 types of yeast used?
Active dry yeast
Instant yeast
Compressed yeast
What is the ideal temperature for active dry yeast?
what else should be added to activate the yeast?
How can you tell that the yeast is still viable?
43-46C w/ sugar
The yeast will produce a foam if it is viable
Why do we want warm water and not hot water or cold water when activating dry yeast?
Temperatures above 60C kill the yeast
Temperatures below 38C cause glutathione to be leached from the yeast cells. The yeast is unable to limit gluten development
How is instant yeast different than active dry yeast?
Why can instant yeast withstand hotter temperatures than active dry yeast?
It is finer, new, more soluble form of dry yeast
Does not need to be rehydrated. Added to the dry ingredients
Water can be as hot as 50C, because it is added to the flour mixture containing yeast, quickly cools the liquid.
How is compressed yeast used?
Should be soften for a short period of time in warm water (27-30C) before combining with dry ingredients
What is a sour dough starter?
Mixture used in making bread w/o using yeast.
A starter is used, it is a living culture of acid. It tolerates yeast and lactobacillus bacteria in symbiotic relationship
How is sour dough starter made?
Mix flour, water, yeast
Left to ferment at RT for a few days. Lactobacillus uses saccharides in flour to produce lactic acid and acetic acid. Low pH, favourable for CO2 formation from yeast.
Describe sourdough bread.
Do they have a longer or shorter shelf life?
more coarse texture, acidity breaks gluten strands. Slightly sour and acidic, due to acetic and lactic acid and other acids.
Longer shelf life
What are the optimal temperatures for yeast growth?
At what temperature is fermentation slow? too fast?
30-35C
below 24C is too slow,
above 37C is too fast
Which sugars are used by yeast during fermentation? (4)
Glucose, fructose, sucrose, maltose
T or F: yeast cannot use milk as a food. Why?
T: Cannot use lactose for fermentation
Why is too much sugar bad during fermentation?
Draws water away from yeast, decreases gluten formation (too tender)
During kneading, what network forms in the dough?
forms a strong network of gluten (gluten in and gliadin proteins)
What is the ideal environment for the gluten network? Why?
Gluten network absorbs more water and forms a better network when cold
A mature ripe dough has an optimal balance of ?
Extensibility and resistance with maximal gas retention.
during fermentation what occurs?
Gluten becomes more elastic, acidity and volume increase
The time of fermentation depends on what? (4)
- Type of flour
- Type of yeast
- Temperature
- concentration of salt and sugar
High temperatures during fermentation produce what kind of dough?
A sticky dough, hard to handle
Production of bacteria that produces undesired flavours
Under fermented doughs produce what kind of bread?
Coarse, compact and small breads
Over fermented doughs produce what kind of bread?
Coarse, small, pale in colour (less sugar). Often have a sour odour (overproduction of lactic acid)
What is the ideal set up when letting dough rise?
hot pan of water in the oven, with the oven light on
How can you tell when dough is done rising?
Push fingers down in the dough. If it does not regain its shape after an imprint is made
Why do we punch dough down? (3)
- Prevents air holes from getting too big and forming an uneven grain.
- Prevents films of gluten from overstretching. -Redistributes yeast, nutrients and heat so that the yeast is surrounded by a new food supply
What is proofing?
The final shorter rising period after the dough has been shaped.
Insufficient proofing causes the product to
tear along its sides during the first few minutes of baking
Over-proofing creates a bread with
large holes or crumbly texture
Can bread dough be frozen? What needs to be done?
Yes
Extra yeast can be added to the recipe, as some will die
Freeze the dough before the final rise
Thaw frozen dough for 3 hours before proofing
Why is the top of the bread dough slashed before placing it into the oven?
To release steam
Why when making some French bread, are ice cubes added to the oven?
To create steam, to form a soft crust
