FOSC201 - food colours and additives

Why food colours are used

Make food more attractive, appetizing

Make up for colour lost during processing

Provide colour to colourless foods

Allow consumers to identify on sight

Food colour definition

Substance that imparts colour when added to food or drink

• natural pigments

• artificial colours

Natural colours - chlorophylls

Green in veg and fruit

• porphyrin ring

• magnesium core

• phytol side chain

Natural colours - carotenoids

Yellow/orange in fruit and veg

Precursor for Vit A

• pumpkin

• carrots

• toms

• sweet potato

Natural colours - anthocyanins

Red, violet, blue in fruits flowers and veg

• red cabbage

• radishes

• aubergines

• berries

change colour with pH

Natural colours - Betalains

Red, violet, yellow

Natural confectionary colourant

• Beetroot

Natural colours - curcumin

Yellow

• tumeric

Natural colours - cochineal

red

• insects

Natural colours - Haem

red/brown

red in oxygenated form

brown when oxidised

• animal blood and muscle

Artificial food colourants properties

Water soluble

Light sensitive

Some pH, SO2 and ascorbate sensitive

Health implications of artificial colours

“possible link between consumption of artificial colours and increased hyperactivity” in children

Food additives definition

Any compound not typically consumed as a food by itself and not normally used as an ingredient in food but is intentionally added to perform a technological function

3 classifications of food additives based on function

Technological

• pH control

• Viscosity

• Stability

• Homogeneity

Biological

• maintain stability

• inhibit degradation

• increase shelf life

Sensorial

• Colour

• smell

• flavour

3 techniques for analysing food additives

Spectroscopic

Chromatographic

E100-E199

Colours

E200-E299

Preservatives

E300-E399

antioxidants, acidity regulators

E400-E499

Thickeners, stabilisers, emulsifiers

E500-E599

Acidity regulators, anticaking

E600-E699

Flavour enhancers

E700-E799

antibioticcs

E900-E999

Glazing agents, gases, sweeteners

E1000 - E1599

Additional additives