Flashcards in Food Science Deck (20):
Give 5 reasons as to why food is cooked?
1. To make it safe to eat
2. To improve shelf life
3. To develop flavours
4. To improve textures
5. To give variety in the diet
What is conduction?
The transfer of heat energy through the vibration of particles
What is convection?
The transfer of heat energy through gases (in a cycle)
What is radiation?
The transfer of heat energy through waves of radiation
Give a few examples of water based cooking methods?
What is braising, blanching, and poaching?
1. Braising - slowly cooking food in an ovenproof pot with the lid on
2. Blanching - part-cooking food in boiling water for a short time before putting it in cold water
3. Poaching - Putting food in a pan of liquid below boiling point (80 degrees)
Give 2 fat based cooking methods?
What is a difference between dry frying and roasting?
Fat is added to food when its roasted but fat isnt added to food that is dry fried
When food is cooked, the proteins d.... and c....
denature and coagulate
What is coagulation?
When denatures protein molecules join together to other molecules and trap water between them
Give an example of a food that uses trapped air?
Describe the process of gelatinisation?
1. When you heat starch granules with a liquid, the bonds between the starch molecules start to break, allow water molecules to enter. This causes starch granuels to swell in size and soften
2. Between 62, and 80, the granules burst open and release starch into the liquid
3. The release of starch causes liquid to thicken
3. When it cools, the liwuid solidifies and a solid gel is formed (used to make set desserts like custard)
What is dextrinisation?
When starchy molecules are cooked with dry heat and the starch molecules in the food break down into smaller molecules called dextrins
What is caramelisation?
When sugar molecules break down at a high temperature, turn brown and change flavour
What does shortening do for food?
Gives food a crumbly texture
Ability to be spread and shaped
How does an emulsifier prevent oil and water from separating?
emulsifiers have two different ends, a hydrophilic and hydrophobic end. Water molecules bond to the hydrophilic side and oil molecules bond to the hydrophobic end to prevent them from separating
Give examples of chemical raising agents?
- Baking Powder
- Bicarbonate of Soda
- Self-raising flour
Give an example of biological raising agents?