Food technology

Food technology

All food contains nutrients and there are five different groups.

1. 0.        0.                        Proteins
2. 1.        1.                        Fats
3. 2.        2.                        Carbohydrates

These are macro nutrients (big nutrients).

1. 0.        0.                        Vitamins
2. 1.        1.                        Minerals

These are known as micro nutrients (small nutrients). We need a lot of macro nutrients and only a small amount of micro nutrients. Macro nutrients are broken down into smaller components in order to be digested.

Water is also very important as we need it to keep our cells digested, but it is not a nutrient.

Macro Nutrients

These are long chains of units. As a plant or animal grows, they build up chains of nutrients.

Fat can also be referred to as lipid.

These long chains are made up of amino acids. Glycerol and fatty acids are the basic building blocks of fat when they are linked together. Carbohydrates are built up of units called saccharides.

Meat, fish, eggs, cheese and milk are five foods that contain lots of protein as they are all of animal origin. Quorn is the only vegetarian option that contains a lot of protein, other than soya.

Lard is 100% fat. Butter and margarine are around 87% fat. Other pure fats are olive oil and sunflower oil; they contain some vitamins and minerals too. Pastry is also quite high in fat.

Carbohydrates are split into two groups: sugars and starch

Sugars:

Sugar, honey, treacle, golden syrup.

Starchy

Potatoes, bread, pasta, breakfast cereal, rice.

These are all filling foods that need to be eaten at every meal.

N.S.P – Non-starch Polysaccharide is also known as fibre. It isn’t a nutrient but it is vital to maintain a healthy digestive system as fluid makes it swell to work properly.

Carbohydrates

Carbohydrates are made up of basic units called saccharides. These are a mixture pf carbon, hydrogen and oxygen. A monosaccharide has a chemical formula of C6H12O6. The formula can be put together in 3 different ways.

1. 0.        0.                        Glucose (G)
2. 1.        1.                        Fructose (F)
3. 2.        2.                        Galactose (Ga)

Any ingredient ending in ‘ose’ is a carbohydrate, these are the only monosaccharides; all carbohydrates are broken down into these components. A monosaccharide is a single sugar molecule.

They link together in chains of two to start off with, these are called disaccharides and you can make these combinations: (G-G) (G-Ga) and (G-F)

You will never get fructose and galactose together. When the disaccharides are formed, a molecule of water is lost, so the chemical formula turns into C12 H22 O11. Two molecules of glucose is called maltose. Glucose and fructose together is called sucrose and glucose and galactose together is called lactose. Lactose is the sugar contained in all natural milk from mammals. All sugar is pure sucrose. Maltose is the disaccharide found in all starchy foods which then go on to form long chains. Any more than three units in a chain is called a polysaccharide, the chemical formula for a polysaccharide is C6H10O5.

The primary function of food is to provide the body with the energy it needs to keep life going. Carbohydrates are important nutrients because they:

•                         Supply energy for all activities
•                         Supply energy to maintain a normal body temperature
•                         Supply indigestible fibrous materials to aid digestion
•                         Are important in the structure of cells

Carbohydrate is the principle constituent of all normal diets, and of all food components it is carbohydrate that generally provides the most energy. Most carbohydrates are plant products. They are the sugars, starches, cellulose and lignin in plants. Some carbohydrate in the form of glycogen is stored in the liver.

All green plants contain chlorophyll; they use this chlorophyll, energy from the sun, water from the soil and carbon dioxide from the air to photosynthesise. At first, very simple monosaccharides are formed. As the process of photosynthesis continues, the monosaccharides are linked together for form disaccharides. Eventually these disaccharides are joined in longer chains to make polysaccharides.

Monosaccharides

Glucose, fructose and galactose- these are known as the three simple sugars. Although they have the same chemical composition, they differ in the arrangement of the atoms. The body is able to use all these simple sugars to produce energy.

1. Glucose is the sugar which forms the repeating unit of which starch is composed. In consequence, it is the breakdown product of starch digestion, and the main form in which all carbohydrates are used by the body.

It is a white solid and has a melting point of 146C. Glucose is found in fruits, honey, onions and sweetcorn. It is also available as a powder, tablets or a colourless liquid. It is often used in the confectionary industry. Glucose is easily oxidised and because of the ease with which it will reduce oxidising agents, glucose is said to be a reducing sugar.

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