Carbohydrates are energy foods. They include sugars, starches and cellulose. Food sources include rice, maize, pasta, flour etc.
Characteristics of carbohydrates:
1. The elements that make up carbohydrates are carbon, hydrogen and oxygen.
2. These elements combine in different ways to form:
- simple sugars for example glucose, fructose, etc.
- complex sugars for example lactose.
- starches for example rice, yam etc.
- cellulose for example present in some vegetables.
3. All sugars are sweet, but they vary in sweetness.
4. Sugars are soluble in water. They form crystals in dry form.
5. Simple sugar are colourless. Starches are white un colour. They are insoluble in water.
6. Starches are often stored as starch grains in plant cells.
7. Starches and complex sugars are broken down to simple sugar before animals can use them.
8. The last products of carbohydrates digestion is glucose.
9. Dry heat causes sugar t melt into a brown honey-like substance called "caramel".
Effects of heat on carbohydrates:
- place about 40g of sugar into a small sauce pan.
- heat gently, do not stir.
- continue heating until there is colour change.
A brown honey-like substance is formed. This is called caramel. This process of production of caramel is known as caramelization. Different shades of brown (from light to very dark brown) can be obtained depending on how long it is heated.
4. Continued heating of sugar after caramelization, causes the sugar to change and burn.