Flashcards in Fat Deck (15)
What is the chemical name for fat? What is the molecule made up of?
It is made up of 3 fatty acids and 1 glycerol.
What is the difference between fats and oils?
Fats are usually solid at room temperature e.g. butter, lard. They are usually from animal sources
Oils are usually liquid at room temperature e.g. olive oil, vegetable oil. They are usually from plants
Name the functions of fats. Name the functions of oils
Providing the fat soluble vitamins (ADEK) - not the water soluble ones (B group, C)
Creates adipose tissue (look like baked beans) which insulates to keep your body warm
Protects our vital organs
Provides the essential fatty acids - omega 3 and 6
Makes all body cells
Concentrated source of energy - 1g = 9kcal
Oils functions are pretty much the same
Name the functions of fat in food
Improves texture (crispy, crumbly, moist)
Makes food easier to swallow
Takes longer to digest and slows stomach from emptying
Name the three pairs that fats can be grouped into
Visible and invisible
Animal and Plant sources
Saturated and unsaturated
Name some examples of visible and invisible fats in food
Visible - fat layers on meat, white marbling inside meat, butter on toast
Invisible - Crisps, biscuits, cakes, fat droplets in emulsions
What is an emulsion?
When fat droplets are distributed in water
Give three sources of animal fats.
Give three sources of plant fats.
Animal: Butter, ghee, lard, meat, meat products, oily fish (e.g. tuna, salmon), hard cheese, cream, eggs, chocolates, pastries
Plant: Vegetable, plant and seed oils, avocados and olives, nuts, nut products, seeds, fat spreads
What is hydrogenation? Is it good or bad and why?
The process of when vegetable oils are ‘hardened’ to be solid at room temperature.
It is bad because it contains trans fat which are thought to cause heart problems. Manufacturers should be reducing this
Describe saturated fats
Single bonds of carbon atoms in the carbon chain. These bonds are hydrogen bonds. They are solid at room temperature and are generally made from animal products. Saturated fats are linked to heart disease since they lead to fatty deposits around the heart. Foods high in this will contain cholesterol. Most people in the UK eat too much saturated fat.
Describe unsaturated fats
A fat is unsaturated if some of the hydrogen bonds are missing. When a hydrogen bond is missing, it creates a double bond of carbon atoms. Unsaturated fats are liquid at room temperature. They can lower your blood cholesterol. Sources include fish, vegetable oils, nuts and seed. Studies SUGGEST that they are better than saturated fat. They reduce the risk of heart diseases
Describe the chemical structure of saturated fat
Single bonds between a chain of carbon atoms with two hydrogen bonds on each C atom. At one end of the chain there is a single hydrogen atom. At the other end there is a single bond with an oxygen atom leading to a single bond with a hydrogen atom as well as a double bond from the C atom to another oxygen atom. All bonds are saturated fully with hydrogen.
Describe the chemical structure of unsaturated fat
The same as saturated except the not all bonds are saturated with hydrogen to there is a double bond between these two carbon atoms. This also can causes a slight ‘kink’ in the structure showing their fluidity at room temperature.
Name the two types of unsaturated fats. What is the difference? Which one is healthier?
Monounsaturated and Polyunsaturated
Monounsaturated fats have one double bond whereas polyunsaturated fats have two or more
Polyunsaturated fats are healthier