Do invisible food colorings exist?

Is it possible to create food dye that is not visible in normal lighting conditions?

For example, something that fluoresces under a blacklight, but is safe to ingest.

Tonic water will fluoresce under uv light, but it isn’t invisible. Just a thought.

I’ve seen commercial goods that have them, but don’t know if the colorants are available at the retail level.

There are quite a few answers if you Google “Glow in the dark food coloring,” though.

^tattoo inks as well.

Could you be a little more specific about what you want to do with it? Tonic water will glow very bright white under blacklight. A chlorophyll rich herb infused oil will glow red.

A lot of drinks that come in individual-serving tetra packs are invisible, because the package is opaque and it is consumed through an opaque straw stuck to the box, so the consumer would have to go to a great deal of difficulty to view the product. Yet, in their infinite wisdom, the marketers have added a few artificial food colorings to the product which no consumer will ever actually see. In practice, these qualify as “invisible” food colorings.

Sure, I was going to dye some salt and use color to gauge how much salt to use without adversely affecting the dining experience.

That’s…really cool! So you need not only something that is invisible under natural light, but also tasteless and that won’t dissolve the salt crystals. I admit, I’m stumped.

(Excellent observation, thanks.)

I’d wager it’s a “confirmation of value” move - drops always spill and if they were clear, there would be a perception that the buyer is just getting flavored water instead of a yummy, healthful blast of… synthetic berry flavor.

What’s even more interesting is that they are food colors that *stain *things. Would seem even more counterproductive except as confirmation that the liquid is somehow “real”…

You have a number of problems to solve - finding a nontoxic tasteless compound that is florescent will be hard: florescence is a consequence of the complex structure of organic molecules, and that complexity is also related to the taste/odour of the molecule. For example, the florescence of tonic water is due to the quinines, which are also responsible for the bitter taste of tonic water. Second, your food may contain strongly florescent compounds that hide your additive. Finally, the food may be opaque so you can’t see any florescence.

Toothpastes may contain brighteners that cause teeth to glow in ultraviolet light. Presumably not all that harmful an additive. The residue left on the teeth should be effectively invisible, but possibly white-tinged.

I am unable to Google the right magic terms to find out what this is. I keep getting a lot of products or generic whitener/brightener discussion without a discussion of the actual additives. Does anyone have access to the book Why There’s Antifreeze in Your Toothpaste?

I think you might be confusing this with the brighteners used in laundry soap, which definitely do work by (1) remaining behind on the fabric and (2) converting UV to visible bluish-white light.

I can’t think of any safe (or even GRAS) substance that would stick to teeth and do this.

Thanks for the replies so far. I was thinking of doing this with soup to begin with. So it can be dissolved in water (or something equally neutral). The soup is non-opaque.

However, maybe it would be easier to use a hydrometer for that purpose.

I was making some wontons and needed to salt the mixture used in the filling. It contains raw meat and egg, so I didn’t want to taste it directly. In that application, the colored salt could be mixed with water. It also doesn’t matter that the filling is opaque since it’s thoroughly mixed. But even if you were salting, say a pork chop, you can still gauge the amount by the color of the appearance of the surface.

So, just to make sure you’re not setting yourself up for failure, have you tested to see if salt water glows under UV light?

If salt water did that, people would have some pretty neat glowy aquariums. Anyone here have a blacklight and a salt-water aquarium?


You lost me there?

Do you mean the taste? Or the look of it - I’m not sure I follow. If looking for the taste - why not check the taste directly - and measure the correct amount?

I think I’m missing something - so I am all up for hearing more.

You mention something about soup being clear and it being useful for that - but I still don’t follow.

Are you looking for an easy to tell sort of general shade of color? But you’d use a black light?

Not sure if it is any help - but they make colored salt - I’m sure you probably know that, but if you are looking for something easy to see - there is always that - not very invisible though.

I want to know how salty my food is without tasting it. For example, I don’t want to lick a raw pork chop. But I need to season it as part of the preparation process before cooking it.

I could use regular food coloring. Suppose I use red. Well the raw meat is already red. So it’s hard to tell how much redder it got. Suppose I use green. Well, now I can tell how much salt was used. But when it’s cooked, a green pork chop might be unappetizing. Sam I am, I do not like green eggs and ham and all that. I suppose brown might work.

Now instead suppose you had a black light in your kitchen and fluorescent salt. You turn on the black light, season your food (pork chop, soup, anything). It glows a certain amount. You can judge how salty by the amount of glow. More glow = more salty.

Once it’s seasoned, you turn off the black light, and your food can be cooked and it does not look an unappetizing shade of neon green. Anyway, that’s the idea in terms as simple as I can make.

The OP is hoping to tell whether or not there’s enough salt in it without having to taste it, as he wants to add the appropriate amount of salt before the meat is done cooking. If he can use the color of the UV-irradiated broth as an indicator, he can tell how much salt is in it without having to taste it.

Another interesting technique to consider is to follow the recipe.

Never heard of the dreaded “season to taste” instruction, eh? I hate recipes that tell you to toss on about 5 integral spices “to taste”. Sorry, this is the first time I’m making this and I don’t know what it’s supposed to taste like yet (that’s why I’m using a recipe in the first place!). How am I supposed to know what ratio of spices to use? Worse in the cases the op describes, with raw meats where tasting is not an option. I’ve also read that salt creates different intensities of flavor depending on when it is added (before or after cooking for instance), so you can’t necessarily add at the end. It’s an annoying little conundrum.

Not even getting into the reverse conundrum where someone who made the recipe loves salt or some other seasoning far more than you do, and writes the recipe with an explicit amount to add.

I feel ya OP, sometimes it’s hard to tell exactly how much salt you’ve added but thankfully I haven’t oversalted yet. Gotten close a couple times though!