DEAR DR. BLONZ: I have some questions about some steaks I recently purchased. They looked really good in the store: a fresh, bright red. The date on the package also indicated that they were fresh. When I got home and opened the package and trimmed the steaks a bit, it became obvious that the middle of the steaks were brownish; only the outside surfaces were red and fresh-looking. The steak didn’t have a bad smell. I have never seen anything like this before. I returned the steaks and got my money back, no questions asked, but also no answers. What could have caused this? Was the meat “stressed”? Was it spoiled, and then treated somehow to look fresh? -- W.B., San Bruno, California
DEAR W.B.: Color and general appearance help determine the appeal of any food product, including meats. Meat is muscle tissue, and when working in the body, it is normally dark-red to purple in color. When exposed to oxygen, a chemical reaction takes place that causes it to turn bright red. This phenomenon is referred to as “bloom,” and involves a reaction with myoglobin, a muscle protein. Below the surface, or even on the bottom of the package, the color can be darker because the reaction hasn’t yet taken place there.
If a cut of meat that has bloomed is allowed to sit out, exposed to the air, a second reaction can occur, causing the red color compound of the meat to oxidize and turn brown. This is not necessarily a sign that the meat is of poor quality, but in time, the flavor will deteriorate.
Interestingly enough, once meat has bloomed, the length of time it stays red can depend on the antioxidant content of the meat. Studies have found that upping the vitamin E content of the animal’s diet can increase the time in bloom.
In general, butchers cut enough to satisfy turnover. They can use an overwrap film to limit air exposure, or even flush packages with a mixture of oxygen and carbon dioxide. All this causes the meat to bloom more slowly. The cutting and packaging processes are coordinated with the time it takes to get the meat into the display case and sold.
Products that turn brown on the surface can be trimmed, allowing a new layer to bloom. But in your case, the meat was red on the surface, but dark all the way through. This would seem to indicate that something was awry. It could very well have been due to stress, as you suggest, but there may have been other factors as well. In any event, it made perfect sense to take it back.
DEAR DR. BLONZ: What are good foods for magnesium? -- C.B., York, Pennsylvania
DEAR C.B.: Magnesium is an essential element needed for normal bones -- in fact, half of our bodies’ magnesium is in our bones -- but also required for normal nerve transmission, muscle relaxation and normal heart rhythm. Good dietary sources include avocado, nuts, bananas, legumes, whole grains, dark leafy greens, milk and oysters.
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