On Multicolored Beef

Not feeling very sprightly today, I've been moving slowly around the house, watching Dr. Who episodes, stirring up caramel corn, calling companies and paying bills. Kind of overdue for lunch, but wanting to eat something before going to the supermarket one last time before Christmas, I opened the refrigerator to find a packet of sliced deli roast beef that needed to be eaten. According to the overcautious Brazilian label, it's already 3 days overdue, but still smells and looks fine. Except for something I've never noticed on meat before: a rainbow colored sheen, like an oil slick, on the edges of the whole tray. Hm. Googling is in order.

Who knew that there was this much science floating about in how we cut our meat? And that there are people out there who believe we can all "agree that we need to understand the scientific basis of the fibrous connective tissues in meat." (I, for one, never knew that this was supposed to be a concern.) There are discussions on boards like this one debating whether the sheen we see is interference, refringence or birefringence...

But don't worry. There's nothing wrong with your meat. It was just cut with a really, really sharp knife. (I could never do it at home.) Thank you, Talho Capixaba, for always understanding what I mean when I say transparent. Shaved, heavenly meat deliciousness.