Eu não vou comentar se é ou não seguro, porque isso poderia ser qualquer outra questão além da coloração marrom da carne. No entanto, o marrom em si não é um problema. Quando a carne é exposta ao ar, ela fica marrom. Isso não afeta o falvor da carne, mas a cor afasta muitas pessoas. Mercearias na verdade vão jogar essa carne fora, não porque é ruim, mas só porque as pessoas não vão comprar. Terrivelmente desperdiçador.
From the USDA: Optimum surface color of fresh meat (i.e., cherry-red for beef; dark cherry-red for lamb; grayish-pink for pork; and pale pink for veal) is highly unstable and short-lived. When meat is fresh and protected from contact with air (such as in vacuum packages), it has the purple-red color that comes from myoglobin, one of the two key pigments responsible for the color of meat. When exposed to air, myoglobin forms the pigment, oxymyoglobin, which gives meat a pleasingly cherry-red color. The use of a plastic wrap that allows oxygen to pass through it helps ensure that the cut meats will retain this bright red color. However, exposure to store lighting as well as the continued contact of myoglobin and oxymyoglobin with oxygen leads to the formation of metmyoglobin, a pigment that turns meat brownish-red. This color change alone does not mean the product is spoiled