The Crazy Sources of Red Food Dye
By: Sam Westreich
Tags: Health, Diet, Science, Food, Environment

Even before I learned that “red velvet cake” was just chocolate cake with red food coloring, I considered it one of my favorite flavors — ironically, second only to (un-dyed) chocolate.

A surprising amount of the food we consume contains various compounds to add color. Marshmallows look white, but they contain blue coloring (to keep them from growing less bright as they sit on shelves). Starbucks uses food coloring in its strawberry drinks. And frozen meat, like fish and crab meat, contains red food coloring to make it more appealing.

But where do we get this food coloring from? In the case of many red dyes, it comes from an unexpected source:

The crushed bodies of a Central and South American insect, called the Cochineal.

What’s the history of our use of a crushed-up bug for our red food coloring needs? What foods contain this insect product?

And can we avoid eating insect-based dye — or are the alternatives even worse?

Let’s dig into the red meat of this cool intersection of food and biology.

Carmine Red, the Aztec Secret

A little insect biology on the Cochineal: this critter is a scale insect (not a beetle) that thrives on cacti. It drills little holes in the cactus and sucks moisture and nutrients from the plant.

In order to repel other insects, birds, or other creatures that may find it to be a tasty snack, the Cochineal produces a nasty-tasting compound called carminic acid. And these bugs contain a lot of carminic acid — between 17–24% of the bug’s dry weight is made up of just this compound!

If you harvest a bunch of these bugs, crush them up, and dunk them in an acidic solution, the carminic acid can be extracted. When extracted and processed through mixing with salts, the result is carmine dye, which is a brilliant, vibrant red color.

(You may also recognize this color under other names, including Cochineal extract, Natural Red 4, E120, or Crimson Lake.)

Thankfully, these bugs grow and reproduce quickly, since it can take 70,000 individual Cochineal insects to produce a pound of Carmine Red dye!

A cochineal insect on its preferred food, the prickly pear cactus. Source.

Cochineal were harvested by the Aztecs in Central America to produce red dyes, and when the Spanish invaded, they claimed the secret of Carmine Red as their own. They managed to keep the source of this dye as a secret for more than two hundred years; it wasn’t until the late 1700s that a Frenchman managed to infiltrate a Cochineal plantation and steal samples of the bug and its cactus food source.

Carmine Red isn’t the only red dye that’s produced today — in fact, the production of Carmine dye was nearly wiped out in the 1900s as more synthetic dyes were discovered — but it’s still in widespread use in various foods. It’s also used in many beauty products, such as in those vibrantly red lipsticks.

But if we can make synthetic dyes, why would we keep using Carmine Red?

Coal Produces Other Colors Besides Black

When we talk about coal, we usually picture a deep, inky black substance. But coal byproducts — and petroleum byproducts as well — can also be used to produce other colors.

There are several azo dyes, which are named after the presence of two rings connected by a pair of nitrogen atoms. These dyes are all synthetic, produced first from coal byproducts, and later from petroleum products.

These petroleum-based synthetic dyes include two, named amaranth dye and Allura Red — which you may recognize from some food labels as Red 2 and Red 40, respectively.

Mmm, love how that Red 40 dye gives my ketchup that added kick that perfectly offsets my hot dog. Photo by Pedro Durigan on Unsplash

Red dyes made from petroleum products are in many of the red-colored foods that we eat, including ketchup, candy, and soda.

But when we’re dealing with consuming chemicals derived from fossil fuels, there are added concerns, generally related to the possibility of cancer.

For example, let’s look at amaranth, the azo compound that’s commonly labeled today as Red 2.

It was used widely throughout the 1900s, up until 1971 — when scientists in the Soviet Union published an article suggesting that it may be able to cause cancer when consumed at high doses. This caused an outcry among the public, and five years later, the FDA issued a ban after concluding that Red 2 was linked with cases of cancer in rats.

Interestingly, although Red 2 is still illegal in the United States, it was not banned in the European Union and is still widely used in food products sold there.

And conversely, the European Union requires that any food containing Red 40 must be explicitly labeled. In the United Kingdom, certain synthetic food dyes are also under additional examination, as there may be a potential link between hyperactivity in children and the consumption of artificial coloring agents. The evidence is not overwhelming, but scientists and government groups are cautious about the human consumption of petroleum products.

Bugs or Petroleum?

In the end, there are potential risks to either artificial color additive that we put in food; the Carmine Red dye produced from the Cochineal insect can occasionally cause an allergic reaction, and it’s technically not a vegan product, since it’s derived from insects.

The many synthetic red dyes, however, including Red 2 and Red 40, are derived from petroleum products and have occasionally been linked to cancer or hyperactivity. Neither of these links has been fully confirmed and they often are based on consuming very large doses — but they’re not guaranteed better options than Carmine Red.

A few years ago, after an outcry over Starbucks’ use of Carmine Red dye in their strawberry flavored drinks, the company promised to replace the dye with another, based on tomato extract. The choice was made to ensure that their menu would be vegan, rather than from health concerns.

In the end, however, I think that most of us, once we get past the initial shock, would rather have a food coloring based on insects, rather than on petroleum derived products. And now you’ve got a fun story to share at the next family barbecue, when you see someone reaching for the ketchup!