Applying Science Flashcards
Why should you avoid storing bakery products in a refrigerator?
Water molecules detach themselves from the starch molecules and the starch molecules begin to take their original shape and harden again. The cool temperatures of the refrigerator make the dehydration process happen more quickly. This is what causes bread to stale
What steps would you take to slow staling in bread and cakes and how do these actions work at the molecular level?
- Bread- add more water because water molecules compete with the amylose-amylopectin interactions involving hydrogen bonds that cause staling.
- Cake- add more sugar because sugars compete with the amylose-amylopectin interactions involving hydrogen bonds that cause staling.
- Both- store frozen or at room temperature, because the staling rate is maximum at 4°C
If you make bread in an atmosphere of pure oxygen why do you get poor gas cell structure?
Yeast fermentation quickly consumes the oxygen so that are no gas cell nuclei to be inflated and so create good gas cell structure
What does solid bakery fat do in bread making?
It is coated with protein which as the dough expands is deposited on the inside of growing gas cells stabilising them
When mixing cake batter what happens during the early part of mixing?
Ingredients are blended and soluble ingredients dissolve
How do you measure how much air is in a cake batter?
By weighing a known volume and calculating its specific gravity (density).
In a high ratio cake batter is the flour concentration higher or lower than in a low ratio cake batter?
Lower
What do sugar crystals do during mixing before they dissolve that helps produce a better cake?
They aid air incorporation by cutting grooves in plastic fat. Air is trapped in the grooves.
Baking powder contains sodium bicarbonate, acid and cornflour. What is the purpose of each component?
Acid reacts with the sodium bicarbonate in wet batter to release carbon dioxide from the sodium bicarbonate. Cornflour keeps baking powder dry so that the reaction does not take place during storage.
In a cake made from flour, sugar, butter, egg, salt, baking powder and water what are the emulsifiers?
Lecithin in the egg yolk and protein, in the egg white
Why might it help to drop a cake in its tin a short distance when taking it out of the oven?
The shock may burst any remaining intact bubbles ensuring that the steam-filled foam is fully converted to a sponge. It will prevent the cake collapsing.
Which of these help prevent excessive gluten development in pastry? • Rolling pastry out • Allowing pastry to relax • Using low protein flour • Keeping everything cool
- Rolling pastry out. No
- Allowing pastry to relax. Yes
- Using low protein flour. Yes
- Keeping everything cool. Yes
Name two oxidising improvers that are permitted in breadmaking?
- Ascorbic acid (vitamin C)
* glucose oxidase.
Why is wheat containing cereal α-amylase avoided for bread making, but fungal α-amylase is sometimes added?
α-amylase is needed during bread making when it digests starch to provide yeast food, but it spoils baked bread by producing sticky crumb.
Fungal α-amylase is easily inactivated by heating so it will not be active in baked bread, whereas cereal α-amylase is more stable and can remain active after baking.
What does xylanase do to dough and how does it do it?
What does xylanase do to dough and how does it do it? Xylanase is a dough softener. Wheat contains arabinoxylan which can bind a lot of water. Xylanase digests arabinoxylan so that it does not bind water. The water that is released softens the dough.
