食品保质期

　　CBS News: experts say consumers often get confused by date labeling on food products, and end up either keeping spoiled food around too long, or throwing away perfectly good food unnecessarily -- costing us billions of dollars.

　　In new a survey by the public health and safety organization NSF International, researchers found that people have trouble understanding and differentiating between common food label terms such as "expiration date," "best if used by date" and "sell by date."

　　Consequently, almost half of Americans do not throw away food until they see mold or color changes. And 17 percent of Americans say they just toss food when it starts to smell.