Colour - Good and Bad Additives

This month Wellbeing's Nutritional Therapist, Kate Arnold discusses good and bad colour in food.

Colour and the appeal of various foods is closely related. Just the sight of food stimulates neurons in the hypothalamus. In trials, people presented with food to eat in the dark reported an important missing element for enjoying their meal: the actual sight of the food. For the sighted, the eyes are the first place that must be convinced before a food is even tried. This means that some food products fail in the marketplace not because of bad taste, texture or smell but because the consumer never got that far. Think how picky we have become with regard to the shape, colour and texture of our food and if any of you saw The Great British Waste Menu, on BBC1 a couple of weeks ago, what happens to so much of our food is that its just dumped because it does not fit into what we find acceptable.

The sight and smell of food is vital to our digestion. We need the salivary glands to start working and good digestion starts with the eyes and the taste buds. Bland food is traditionally the food for people who are recovering from illness. Whilst visiting someone is hospital recently, the bland food epidemic so common in institutions was at the forefront of my mind. White macaroni cheese on a white plate followed by white ice cream in a white container failed to get my taste buds going. Not an ounce of colour anywhere and hardly appealing to the eye.

There are three main classes of colour in foods: natural colours, browning colours, which are produced during cooking and processing, and additives. The principal natural colours, most of which, in refined form, are used as additives, are the green pigment chlorophyll, the carotenoids, which give yellow to red colours, and the flavonoids, with their principal subclass the anthocyanins, which give flowers and fruits their red to blue colours.

There has been much interest in carotenoids in recent years especially in beta carotene - besides being a natural orange pigment (in carrots, mango etc) it is converted in the body to vitamin A and has antioxidant powers and may be beneficial in reducing the risk of some cancers.

Food additives

Increasingly, food additive colours are based on anthocyanins derived from sources such as red grapes or beet but the first additive colours were the synthetic dyes. When synthetic dyes were discovered (mauve was the first, discovered in 1856 by the English chemist William Perkin) they were initially used in textiles, but by 1900 eighty chemical dyes were used in food in the USA. Chemical dyes have stronger colours than natural colouring agents such as cochineal. Many of these dyes were originally derived from coal-tar, and were commonly called ‘coal-tar dyes'. The term is still sometimes used although the dyes are no longer made from this source. Chemically, the dyes are azo dyes, that is they contain the azo group, which confers bright colours which vary in hue depending on the rest of the molecule.

In 1937 the dye butter yellow (dimethylazobenzene) was found to cause cancer in rats. The other azo dyes became suspects and one by one they have been weeded out of the list of acceptable additives. Today a limited range of azo dyes are still used. Several years ago, the makers of M&M's which contain a variety of different coloured chocolate sweets, added blue to its pack. Apparently, the result of a vote by M&M fans. It does raise a few questions as of all the colours in the spectrum, blue is actually an appetite suppressant. Weight loss plans suggest putting your food on a blue plate. Or even better than that, put a blue light in your refrigerator and watch your munchies disappear!

Colour in foods can be seen mostly in fruit, vegetables, salad and herbs and as we are all meant to be eating five portions every day, we could be eating a rainbow of different colours on a daily basis. Colour is of course added to foods, and only as recently as ten years ago, buying a strawberry yoghurt still meant buying a pink yoghurt that had never really seen a strawberry but was full of colouring. We have come a long way now and most shoppers are savvy to the horrors of brightly coloured foods. I think its still pretty obvious if there is an artificial dye in a food, as it will look unnatural but still check the label. You can get wonderful natural colours like turmeric, saffron etc. Purified raspberries, blueberries or strawberries give terrific colours. Even peas made into soup have a fantastic natural colour. Colour is also so important in children's diet as it is hard enough getting the five portions of fruit and vegetables into their daily diet. Colour (natural not added!) can really help-children as we know love bright colours.

Kate's Guide to Good and Bad Additives

Colours (E100 -E180)

Good
Riboflavin E101
Carotene E160
Bad
Tartrazine E102
Coal or azo dyes E104-142
Caramel E150
Coal tar dyes E151-155
Aluminiun E173
Silver E174

Preservatives (E200-290)

Bad
Sorbates E200-E203
Benzoates E210-E219
Sulpur-Sulphites E220-E227
Misc E230-E249
Nitrates E250-E252
Diacetate E262
Propionates E281-E283
Carbon dioxide E290
Good - there are very few good preservatives!

Antioxidants (E300-E321)

Good
Ascorbates E300-E304
Tocopherols E306-E309
Bad
Gallates E310-E312
BRA E320
BHT E321

Emulsifiers, stabiliser and others (E322-E925)

Good
Lecithin E322
Nicotinic acid E375
Pectin E440
Bad
EDTA E385
Carrageenan E407
Sulphuric acid E513
Potassium hudronxideE525
Sodium ferrocynadeie phosphate E535
Sodium injositate E631
Monosodium glutamate E621
Chlorine E925

Coloured foods and their health benefits

Green
e.g’s artichoke, asparagus, beans, broccoli, celery, leeks, peas, pepper, sprouts, courgette, marrow, kale, spinach, spring greens. Benefits: phytochemicals inc lutein. Good for detoxing.

Red, purple and orange
e.g’s beets, carrots, aubergine, pumpkin, squash, red cabbage, red peppers, sweet potato, tomato, yam, noni, pomegranates.
Benefits: high in lycopenes. May help decrease risk of prostate cancer.

Leafy green
e.g’s Bok choi, cabbage, chicory, chives, endive, kale, lettuce, parsley, spinach, swiss chard, watercress. Benefits: good levels of magnesium and excellent for cultivating prebiotic activity in the gut.

Blue/Purple
e.g’s bilberry, blueberry, elderberry
Benefits: high in anythocyanins. Good for the heart, improve circulation and prevent blood clots.

White/Green
e.g’s garlic, onions, leeks, celery.
Benefits: high in allicin which is anti-viral, anti-fungal and anti-bacterial. Celery contains organic sodium which keeps fluids in joints healthy.

Orange
e.g’s squash, pumpkin, carrots.
Benefits: rich in beta carotene - a by product of vitamin A which aids cell growth.