Key points
Lipids include fats (solid at room temperature) and oils (liquid at room temperature).
Lipids are an important part of a healthy diet. The body uses lipids as an energy store, as insulation and to make cell membranes.
Lipids in food
Video
Discover how lipids are used in making ice cream
My name's Raj. I make and sell ice-cream in my ice-cream parlours.
In order to make ice-cream, you need three essential ingredients, that's milk, cream, and sugar. The milk contains some fat, and the cream that we're using also contains fat as well. And fats are a type of a lipid. Fats are generally solid at room temperature. Examples of that is butter, lard.
Oils are a type of lipid. They're liquid at room temperature, vegetable oil for example.
When you try to mix lipids with water, it's very difficult to get them to mix, so they're insoluble. So we've got various different elements in the ice-cream mixture, one of which is water, one of which is fat. And in order to get those to bind together, we need an emulsifier. An emulsifier bonds those two things together to ensure that they don't separate when we freeze the mixture into ice-cream.
An example of an emulsifier is egg yolk. And that's used in traditional baking or traditional ice-cream making. We use alternatives to egg, use something called Guar which is a natural product but has the same properties.
It's extremely important to get the ratios right in ice-cream. If you put too much water in the ice-cream, for example, when you freeze the ice-cream, that water will turn into crystals which is not really nice when you're eating the ice-cream.
The best thing about my job is making sure my customers are completely satisfied, they come in with a smile on their face and they leave with a smile on their face, but also I get to eat my product.
Can you answer these questions based on the video?
1. What do you need to make ice cream?
2. What is the name for something that binds things together such as egg yolk in ice cream?
Milk, cream and sugar.
An emulsifier.
The types of lipids
Lipids are formed of carbon, hydrogen and oxygen atoms. There are two types of lipids:
Oils - These are liquid at room temperature. Fish has a high oil content.
Fats - These are solid at room temperature. Butter is high in fat.
Here are some examples of foods which contain lipids:
| Fats | Oils |
|---|---|
| Butter | Seeds |
| Beef | Nuts |
| Cheese | Fish |
How does the body use lipids?
Every cell in your body has a cell membrane which is made of lipids. Some hormones, including sex hormones, are made from a lipid called cholesterol.
Fat is also an important energy store for the body. In addition, the layer of fat under your skin provides insulation and thin layers of fat protect vital organs.
How much lipid do you need?
Lipids are an essential component of a balanced diet. In the body, lipid molecules can be broken down to make smaller molecules of fatty acids and glycerol.
Some fatty acids, called essential fatty acids, are vital for health. They can be found in foods such as nuts, seeds or fish.
It is important not to each too much fatty or oily food. This is because small amounts of lipid-rich foods can store large amounts of energy. Eating too much fatty or oily food, whilst not getting enough exercise, may cause obesity. Adults and teenagers are advised to eat no more than 70 g of fat per day.
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