They were thin, pale, and irregularly shaped. Some appeared to be embedded in the roast, while others seemed to protrude from the surface. The immediate thought was understandably alarming:

“Are these worms? Could the beef be infested with parasites?”

It is a question many people might ask when confronted with an unfamiliar structure inside meat.

However, unusual-looking material in cooked beef does not automatically mean that the meat contains parasites. Beef is made up of several different tissues, including muscle fibers, connective tissue, fat, and collagen-rich structures. Some of those tissues can change dramatically in appearance during slow cooking.

In fact, what looks frightening at first may simply be a normal part of the meat becoming more visible after hours of cooking.