A lot of foods have expiration dates – even when it’s not printed on the package. So, here’s how to store your food so it packs a bigger nutritional punch longer, courtesy of Prevention magazine:

• First, tomato products. Canned tomato juice, sauces and ketchup lose about half their cancer-fighting lycopene after three months in the fridge, even when they’re unopened. Your best bet: Make homemade sauce using boxed whole or diced tomatoes, because lycopene lasts longer in solid tomatoes. If your ketchup sits in your fridge for months, buy smaller bottles.
• Next: Potatoes. Farmers often store potatoes for five months before they’re shipped to market. Even when stored properly someplace cool, dark, and dry, they lose half their vitamin C after eight months. The fix: Look for smaller, “new” potatoes – which have more vitamin C to begin with, and buy only what you can eat in a few weeks.
• Another product with an invisible expiration date: Olive oil, which loses half its antioxidants after six months. The fix: Don’t store olive oil near the stove, or leave the cap off for long – because it’s sensitive to oxygen, heat and light.
• Then there’s berry jam, which loses at least 18% of its antioxidants in four months at room temperature. The fix: Store jams in the fridge even before you open them.  
• Pasta loses half its riboflavin after being exposed to light for just one day. The fix: Store your pasta in opaque ceramic containers far from the hot stove.
• The last expiration date not printed on the package is for milk. Fat-free milk in glass bottles loses 10% of its vitamin A after two hours in the dairy case. So, buy your milk in paper cartons.