How safe is it to buy beef or fish at a reduced price because the “sell by” date is about to expire? What are signs of bad steak? Does browning around the edges indicate it's spoiled? —J.B., Lubbock, TX

You should buy fish and meat before the sell-by date and generally either use within a day or so or freeze it, food scientist Linda Greene says. In general, less-than-fresh food won’t make you sick, as long as it’s handled properly and kept at 40° F or colder, but don’t eat it if there’s a color change and an off-odor. Meat darkens when exposed to air, so a change in color alone doesn’t necessarily mean it’s gone bad, but don’t eat it if it’s slimy or tacky. Fish should smell fresh and mild, not fishy, sour, or ammonia-like. The flesh should be shiny and firm and should spring back when pressed.

Read more on how to prevent food-borne illness.