Light Affects Perceived Meat Color

By Christopher R. Raines

You may have never considered the enormity of light nor how light affects the perceived color of everything we see – meat included.  It is very possible (I’ve seen it happen! And you may have, too!) that you take something out of the self-serve meat case at the grocery store, move on to a different section, and somehow, some way, the meat looks different.  Perhaps it looks grayer, or perhaps there’s a yellowish tinge to it.  Does this mean that the fresh pork chops you’ve selected have gone “bad” in the very short time between taking it out of its display case and moving on to the potato chip aisle? Probably not. (And as an aside, it’s always best to select meats and other refrigerated foods last, then proceed directly to the checkout lane.) Presently,  most meat cases are illuminated with fluorescent bulbs, and much of the remainder of the store may be illuminated by some sort of metal halide or other “industrial light.”  So now you might be thinking:  “Ah ha!  They lit the meat case funny to try to dupe me into buying something that was a funny color!”  Again, probably not. In all reality, the light in the meat case may be “truer” than the rest of the light in the store.

Consider the visible light spectrum, and all the wonderful colors it can create — as in, all the colors we see.  In short, certain light types emit certain wavelengths, and those wavelengths that are reflected by an object are the same which we see and therefore, we are able to associate a color with the object.  This is why light type can so greatly affect the perceived color of fresh meat and subsequently impact perceived freshness and quality.

Fresh beef, pork and chicken, and salami illuminated by seven different fluorescent lights.  Original photos taken at and compilation developed at Kansas State University.

Fresh beef, pork and chicken, and salami illuminated by seven different fluorescent lights. Original photos taken at and compilation developed at Kansas State University.

The mosaic image above is one of my favorites pictures! What you see in it are pieces of the same beef steak, pork chop, chicken breast, and salami slice displayed under seven different kinds of fluorescent light.  As clearly illustrated, there are marked variations in appearance of the same product.  Using the images above and previous information supplied in the literature (1, 2, 3), I and a group of other meat scientists at Kansas State University developed a guide we call Meat Lighting Facts and it is available for download*.  In this guide we explain some of the jargon used by the lighting industry to describe lights, and supply some “Do” and “Don’t” tips for meat retailers wanting to best display meat products.

*When viewing Meat Lighting Facts on your computer screen, or if you print it out yourself, keep in mind that the true color may have been slightly distorted from the original. All monitors and printers are a little different, and so are the colors they render. Even so, what you’re viewing should illustrate similar color differences among different lights featured in the guide.

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