E- Numbers

S3 Chemistry Mini-Assignment

What are E- Numbers• E numbers are codes for chemicals which can be used as food

additives for use within the European Union (the "E" prefix stands for "Europe").

• They are commonly found on food labels throughout the European Union.

• Having a list for food additives was first agreed upon in 1962 with colours.

• In 1964 the directives for preservatives was added, 1970 for antioxidants and 1974 for the emulsifiers, stabilisers, thickeners and gelling agents.

In this assignment we will investigate the E –Numbers relating to colouring agents to foods.

• E- Numbers from E 100- E199 are related to colour. • Some sweets and other food stuffs gain certain

colours by mixing E- Numbers. • Think, how many E-Numbers must one packet of m&

m’s contain. • Different E- Numbers are used to gain different

colours e.g. E129 – allura red • It is essential people are made aware of the E-

Numbers contained in their foods for many reasons.

Reasons to Avoid E-Numbers

• If you already suffer from asthma or any other form of breathing problem there are some E numbers that could make your condition worse.

• Some people may be allergic to certain E- numbers.• Some E -numbers may cause stomach upset. • Some of the E -numbers that the UK government

have suggested children should avoid, particularly if they’ve shown any signs of suffering from hyperactivity, are as follows.

Due to this….

• It is essential chemists can separate coloured substances into their different E- Numbers.

• Once separated chemists can identify certain E- numbers and research the health effects these E- Numbers may cause.

When doing your own research, you must research the following E- Numbers

• Allura Red (E 129)• Brilliant Blue (E 133)• Quinoline Yellow (E 104)• Sunset Yellow (E 110)• Green S (E 142)• Carmine (E120)

Chromatography is a technique used to separate a mixture substances.

There are two phases in Chromatography:

1. Mobile phase2. Stationary phase

The mobile phase flows through the stationary phase and carries the components of the mixture with it.

The different components travel at different speeds.

Chromatography

Think of Chromatography as a race .......

Waiting at the starting line, you have a mixture of chemicals. Just like the runners waiting to start.

When the race starts, the runners spread out because they have different abilities.

In exactly the same way the chemicals in the liquid mixture spread out because they travel at different speeds over the stationary solid.

Smaller, more soluble molecules will travel through the stationary phase faster and will be identified first.

Bigger, less soluble molecules will travel through the stationary phase slower than smaller molecules and will be identified last.

Packing the Column

1. Insert a loose plug of mineral wool into the syringe.

2. Add talc to roughly 8cm3 line. Insert the plunger to ensure the talc is fully compressed.

3. Insert another plug of mineral wool. Insert the plunger, press down firmly and remove.

4. Add 2-3cm3 of distilled water.

5. Insert the plunger and press to force the water through.

Extracting the Dye

1. Add 5 ml of distilled water to a beaker.

2. Put two sweets (of the same colour) into the water.

3. Once the dye has dissolved, remove the sweets from the mixture.

4. Put the mixture aside, this will be used later.

Running the Column

2. Put a layer (a few mm) of fine sand on top of the dye.

3. Fill the syringe to 10cm3 with distilled water.

1. Add 0.5cm3 of the extracted dye using a pasteur pipette.

4. Insert the plunger and apply pressure.

Collecting the Dyes

2. When you see the first hint of colour, start collecting in the first test tube.

3. When you see the colour changing, start collecting in a second test tube.

1. To start with, let the liquid drip into a beaker. Watch very carefully for the first signs of colour.

4. Each colour should be collected in a different test tube.

5. If the syringe runs dry add more distilled water and continue.