Mad Food Science

Chemistry + Cupcakes

Food Colouring

As you can imagine, I was quite tempted to blog about unicorns this week. Being both magical and delicious, unicorn is the perfect ingredient for any dish. However, the one that I acquired (seriously, you can find anything at St. Lawrence Market!) somehow managed to escape in the night, and all it left behind was a handful of magical rainbow turds.

I don’t know what it is, but there is just something more fun about making coloured things vs. non-coloured things. It’s the (not-so-inner) child in me. But what is food colouring? And where does it come from? And how long will my tongue be purple?

Food colouring can be either natural or artificial. The natural ones can come from all sorts of different plants, and even animals or insects. Basically, anything that can stain can be a food colouring. Beets, algae, tumeric, caramel – all natural sources of colour. And that’s fine and good, if you’re a dowdy pioneer woman who wants a pretty purple sun dress to impress the burly stable boy. But real men prefer chemicals.

Blue #1 (E133) is made of aromatic hydrocarbons from petroleum (sounds appetizing, right?), and gives the brilliant blue colour you see in “blue raspberry” products: candy, popsicles and whatnot. Only about 5% of it is absorbed by your body on its way through, so the other 95% will usually lead to blueish-green stools (yes, I’m going to be adult about this and call them “stools”). Strangely, Blue #1 can also cause an allergic reaction in people with moderate asthma.

On the positive side, the chemical structure of Blue #1 is similar to another compound (OxATP) that blocks nerve damage following spinal injury – but without toxic side effects. A study from 2009 demonstrated that rats that had Blue #1 injected into their injured spines showed improved recovery.

Red #40 (E129) was originally made from coal tar, but is now made from petroleum like it’s blue cousin (I guess that’s a step up?). It’s not very popular in Europe, where it’s either not recommended for children or outright banned, but in the USA it’s used for all sorts of food, cosmetics and drugs. Red #40 has had a scandalous life, with various studies linking it to a rise in ADHD in children (hence the banning), but since correlation does not equal causation, it stays in use in many places throughout the world because compared to other red colourings it’s not that bad. I doubt that brings much comfort to any of you parents.

Yellow #5 (E102), or tartrazine, is a lemon yellow dye from the same chemical family as Red #40. Similarly, its been linked to hyperactive disorders in children like ADHD, and like its blue cousin its been linked to allergic reactions. Many manufacturers are now trying to steer towards easily-produced natural yellow food dyes, like beta carotene, to avoid both the bad reactions and the bad press. Speaking of bad press, during the 90s, Yellow #5 was rumoured to be associated with decreased potency, testicle and penis size, and sperm count – none of which was ever scientifically proven.

Yellow #6 (E110) is actually an orange colour (think Orange Crush) called “Sunset Yellow” that’s widely used in food products. It’s why the powdered cheese on Cheetos stains everything you touch for days afterwards. When mixed with red food dyes, it creates a brown colour that’s commonly added to chocolates and caramels.

Green #3 (E143) is a sea green colour, and is the least used of all the artificial food dyes. Probably because its been linked with tumours and mutations in animal experiments. Yikes! A safer place to use Green #3 is in the molecular biology lab, where scientists use it to stain DNA and proteins to help make them visible.

Blue #2 (E132) is an indigo dye that’s also used a lot in scientific research because of its ability to indicate pH. Below pH 11.4, it’s indigo, but above pH 13.0 it turns yellow. Handy if you can’t remember which bottle is full of bleach! (hint: it’ll be the one that turns yellow, or, you know, the one that smells like bleach). In obstetrics, it can be injected into the amniotic sack to check for leaks. Fetuses and bicycle tires: more in common than you thought!

Red #3 (E127) is a cherry-pink colour that’s commonly used in Europe where Red #40 is banned, but less so in North America. It’s the dye in those tablets that the dental hygenist made you chew to show you all the plaque on your teeth (followed by an instruction/guilt session on how to brush properly).

All of this research leads me to only one conclusion:
Unicorns are on the verge of extinction because all of the food colouring they ingest (as evidenced by rainbow stools) has given them such bad ADHD that they can’t even focus for long enough to procreate.

Mind = blown. You’re welcome. 

  • 4 March 2012
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