You know the benefits of a healthy diet loaded with fruits and vegetables, but navigating the produce aisle can be tricky. How do you differentiate the good apples from the bad ones? Here are four tips for making sure you're picking the best produce.

1. Buy in-season produce

Doug Ranno, fresh produce expert and chief operating officer and managing partner of  Colorful Harvest, points out that the shift to a global economy has brought many fruits and vegetables to the shelves of your local supermarket year-round. But he warns, "Just because it's sitting in the produce aisle, doesn't mean it's fresh, tasty or nutrient-rich."

Ranno recommends buying, cooking and eating produce that is in-season. If you aren't sure what fruits and vegetables are in-season in your area, check out Epicurious' interactive map.

An added bonus? Seasonal produce tends to be less expensive than out-of-season fruits and vegetables.

2. Avoid bruised produce

You don't want to get food poisoning because you picked up from bacteria-ridden bell peppers at the store. Produce may come into contact with bacteria in the soil or water while it is growing, or at some point during the storage or preparation process, the U.S. Food and Drug Administration (FDA) says.

Don't bring home bruised, moldy, wilted or mushed produce. Wilted leaves could be a sign that the vegetable has overstayed its shelf life. Check for signs of insect damage (you don't want to find a worm in your apple!).

Keep in mind that your produce doesn't become protected from harm the second you put it in your shopping basket. Make sure to keep all fresh fruits and vegetables away from raw meat, poultry and seafood both when you are transporting your groceries and when you are cooking.

3. Check the packaging

If you are buying a pre-cut item, inspect the packaging for holes, rips and tears. You don't want to buy it if the outside wrapping or container is not totally intact.

Also make sure you buy bagged salads or cups of grapefruit slices that have been properly refrigerated or surrounded by ice. Take note of the use-by date. Have you ever seen a bag of mixed salad after its expiration date has passed? If you haven't, just know that the lettuce turns brown, slimy and is enough to make you lose your appetite.

Love peaches but can't seem to get the hang of picking out the perfect the best ones? Check out this supermarket survival guide for item-by-item tips for selecting the best fruits and vegetables.

4. Go for bright colors

Ranno says that the more vibrant the color, the more nutrient-rich the produce. For example, red-hued vegetables and fruits like tomatoes and watermelons contain lycopene, a potent antioxidant that has been associated with a lower risk of prostate, lung and stomach cancer.

So, when shopping for fruits and vegetables, aim for a colorful cart. You want your cucumbers to actually look green and your carrots to be bright orange.

"The advantage of eating a variety of colors is that you get a variety of nutritional benefits that help build a strong immune system," Ranno adds.