What Additive Is It...?

[mneeley490]

I've been looking at some of the great stuff you all have been making, and this thought occurred to me.

What is it that gives some store-bought cured meats, like Canadian bacon or ham, that titanium, rainbow-colored effect? Always wondered if I was being poisoned?

 

[voyager 663rd]

A reaction as a result of curing the meat with #1 cure (nitrite is the chemical responsible).

 

[cptnding]

Yep it's the curing and to me the dryer the cut of meat is the more pronounced that look will be.
Try making some of Bear's dried beef. Every slice is a rainbow
I've never noticed it with belly bacon even dried for over two weeks after smoking so maybe fat content has something to do with it as well.

 

[Fueling Around]

The leaner cuts of meat, cure #1, and added salt produce the rainbow sheen.
I don't see as much sheen in my low salt cures of pork tenderloin into Canadian bacon.
Fattier cuts such as pork belly or beef navel has the sheen in the meat, but you cannot see it from the glare of the fat.

 

[zwiller]

Not sure it's cure, I've had it happen on non-cured fare. This is EOR made as sauerbraten. No cure, dry brined with salt, pickling spice, and WP then SV'd. Yeah, it was glorious. Run before this I used the traditional wine etc and it totally denatured and turned to mush.

 

[SmokinEdge]

I believe it’s the composition of the lean muscle fibers. It’s normal.

 

[smokerjim]

See this quite often with eyerounds. Has nothing to do with cure.

 

[PolishDeli]

The greenish sheen (iridescence) you see is often associated with cured meats; but the curing does not cause it directly. i.e., you are not seeing NaNO2 or any of its byproducts.

Instead, what you are seeing the result of a “thin-film interference effect”. It is the same physics that causes rainbows in soap bubbles and puddles at gas stations. When light hits a smooth surface with a few extremely thin, stacked layers, the light reflects off each layer. These reflected light waves then overlap and cancel or reinforce each other, which splits the light into its individual colors (the rainbow effect). In the case of meats, the thin layers causing the effects are A-bands (myosin filaments) and I-bans (actin filaments) which are proteins that make up sarcomeres – the basic units of muscle fiber.

This effect is seen in cured meats because the processing (curing and cooking) causes the muscle fibers to tighten and align more neatly. When the meat is sliced smoothly across the muscle grain (perpendicular to the fiber), it cleanly exposes the highly-organized, repeating stack of A-bands and I-bands, making the iridescence visible.

 

[chef k-dude]

According to AI scraping the web:

"The rainbow colors on meat, known as iridescence, are caused by light diffraction due to the microscopic structure of the meat fibers. This phenomenon is normal and does not indicate spoilage, as long as the meat is fresh and has no off odors or sticky texture."

 

[mneeley490]

Wow, okay, good to know it's not some chemical they use to clean the processing equipment.
I've never seen it on anything I've made.

 

[zwiller]

Here I was thinking it was some kind of salt crystallization.

 

[Florida Chris]

According to AI scraping the web:

"The rainbow colors on meat, known as iridescence, are caused by light diffraction due to the microscopic structure of the meat fibers. This phenomenon is normal and does not indicate spoilage, as long as the meat is fresh and has no off odors or sticky texture."

The AI explanation is accurate. It's called Rayleigh scattering. Same reason the sky is blue during the day and orange at sunset.

During the day sunlight takes a more direct path us. This allows the shorter wavelengths (blue light) reach us. Blue is UV, so this also explains why you get sunburns in the afternoon but not at sunset. The sun isn't farther away at sunset (at least not enough to matter) but the atmosphere filters out the UV.

Opposite happens at sunset. There's more of the atmosphere for the light to travel thru, which filters out the shorter wavelengths (blue) but allows the longer wavelengths to pass thru (red).

No, I didn't stay at a Holiday Inn last night. Photonics Engineer for 30 yrs.

I play with lasers and get paid to do it. And absolutely YES!!!!! It's fun AF every day.

 

[PolishDeli]

F Florida Chris
How would Rayleigh scattering cause iridescence? Rayleigh scattering is caused by electromagnetic radiation (light) being elastically scattered by particles whose diameter in much smaller than the wavelength of light. It is fundamentally different from diffraction and thin film interference.

Diffraction is caused by light bending as it passes through small openings, periodic structure, or edges. Think of the grooves in a CD: light is bent when it reflects from those grooves. This bending creates different paths for the light waves. These different light paths overlap and result in constructive or destructive interference, which separates the light into a rainbow

Thin film interference is caused by light reflecting from planer interfaces and constructively/destructively interfering to cause a rainbow (like a puddle at a gas station).

Meat iridescence is most likely caused by thin film interference (https://doi.org/10.1111/ijfs.14626).

 

[hoity toit]

Not sure it's cure, I've had it happen on non-cured fare. This is EOR made as sauerbraten. No cure, dry brined with salt, pickling spice, and WP then SV'd. Yeah, it was glorious. Run before this I used the traditional wine etc and it totally denatured and turned to mush.

View attachment 724984

That looks awesome my friend. I would chow down on that anytime.

HT