Many companies including McDonald’s and Kellogg are purging artificial colours from their foods, but don’t expect your cheeseburgers or cereal to look much different.
Colours send important signals about food, and companies aren’t going to stop playing into those perceptions.
McDonald’s announced in September that it had removed artificial colours from many of its burgers and Kellogg has pledged to remove them from its cereals by the end of this year.
But it’s not just processed and packaged foods that create illusions with colours .
Check the packages of most cheddar cheeses, and they’ll likely list an ingredient called annatto, a plant extract commonly used for colour.
The practice reaches back to when cheesemakers in England skimmed the butterfat from milk to make butter. The leftover milk was whiter, so cheesemakers added pigments to recreate butterfat’s golden hue.
Another cheese that sometimes gets cosmetic help: mozzarella.
Mozzarella sometimes gets its bright white from titanium dioxide, a common ingredient derived from natural sources.
Without it, mozzarella would be beige or off-white. T he whitening is done because most mozzarella starts with cow’s milk, which can have yellow hues.
In Italy, mozzarella is traditionally made with water buffalo milk, which is whiter because the animal can’t digest beta carotene .
Many home cooks think darker egg yolks are fresher or more nutritious. But the colour may be the result of marigold petals, alfalfa or colouring products in chicken feed.
Yolk colour is primarily determined by the carotenoids — naturally occurring pigments in plants — that hens eat, and it’s easy to change yolk colours by simply altering hens’ diet.
Yolk colours varied more when chickens were fed whatever was available in the barnyard. Commercial feed has made yolk colours more consistent, but synthetic colour additives are not allowed for chicken feed.
Bright pink flesh may signal freshness to shoppers eyeing salmon filets, which is why farmed salmon may have been fed synthetic astaxanthin, a version of a naturally occurring compound.
The Food and Drug Administration notes that manufacturers have to declare on labelling if colour additives were used for salmon.
It may not sound appetizing, but manufacturers know the difference colour can make. Salmon with a darker flesh can more per kg when offered side by side with lighter salmon, according to research by animal feed maker DSM.