Fats and Oils

a macronutrient
general term is lipids
oils are liquid at room temperature and fats are solid
composed of fatty acids and glycerol.

Fats are a good source of energy and insulation. It keeps our bodies warm because it is stored under the skin and a layer of fat protects our vital organs such as liver and kidneys. It is a good source of vitamins D, E and K and helps us to feel full after eating, called a feeling of satiety. It is used in foods to give texture and flavour - for example, shortcrust pastry; fat is rubbed in to shorten gluten strands.

Saturated and Unsaturated Fats:

Different combinations of carbon, hydrogen and oxygen produce different types of fats.

Saturated fats:

One carbon atom cobmined with two hydrogen atoms
Mostly solid at room temperature
For example, butter, lard, animal fat found on meat
Too much saturated fat can cause high blood cholesterol, increased risk of heart disease, diabetes and obesity.

Unsaturated fats:

Normally liquid or soft at room temperature.
Monounsaturated fats contain a pair of carbon atoms with one hydrogen atom attached, allowing them to take another carbon atom. They are soft at room temperature but harden in the fridge. They are found in animal and vegetable fats such as avocado and olives and can help to lower blood cholesterol and reduce the risk of diabetes and cancer.
Polyunsaturated fats have two or more pairs of carbon atoms that can take up more hydrogen atoms. They are soft and oily at room temperature and in the fridge.

Hydrogenation:

When manufacturers change the structure of fats in products by adding hydrogen to vegetable oils; the process of turning oils into solid fats.
This creates man-made molecules called trans-fatty acids
Turns oils into solid fats and makes them behave like saturated fats. It is much cheaper than solid fats like butter
Used in foods like cakes and biscuits
Very bad for your cardiovascular system, and may increase risk of heart disease and breast cancer.
Many manufacturers are reducing the use of trans-fatty acids.

	Created by holly m over 7 years ago

Note on Macronutrients and Micronutrients, created by holly m on 13/02/2019.