Valentine’s Day is Friday, and for many of us that means one thing—chocolate!

If you’re a chocolate lover looking for the best indulgence, there’s some good news. According to a study in the Journal of Agricultural and Food Chemistry, researchers with the U.S. Department of Agriculture’s (USDA) Agricultural Research Service have found a new scientific way to verify the origin of cacao beans. That means you can find out which type of cacao you're eating and where it came from.

Read More: Chocolate Is One of Six Healthy Valentine's Day Gifts »

Cacao bean types are sometimes mixed up during the harvesting process, so a manufacturer might think they're getting a high-quality bean, but until now there was no way to tell. The new method screens beans based on their DNA and can match the beans to their corresponding tree.

The ability to authenticate premium and rare varieties of cacao means buyers will know which product they're paying for.

Lyndel W. Meinhardt, Ph.D., a USDA scientist familiar with the research, said that there are about 13 or 14 different types of cacao beans.

“This only really affects the premium types because [manufacturers] get more from it,” Meinhardt said. “We’re actually adding another level of authentication on top of the sole source. It’s kind of taking your premium chocolates into the next realm.”

12 Ways Sex Helps You Live Longer »

Is Chocolate Good for You?

You can discern healthier chocolate based on its cacao content. The greater the percentage of cacao, the darker the chocolate, and the more heart healthy flavonoids it contains. 

Andy Bellatti, a nutritionist from Las Vegas, said cacao (and cocoa, once it’s processed) is a healthy food—but certain types are better for you than others. The three main fats in cocoa butter are oleic acid, the same heart-healthy monounsaturated fat found in olive oil; stearic acid, a saturated fat the body converts to oleic acid; and palmitic acid, which has been shown to slightly increase "good" HDL cholesterol.

Decadent Individual Chocolate Cakes at 210 Calories per Serving »

Dark chocolate is rich in antioxidants, fiber, magnesium, and copper as well.

“You need to know how to find [chocolate] in ways that are minimally processed so you get the most nutritional bang for your buck,” Bellatti said. He advises picking a chocolate with the fewest number of added ingredients.

It may be good for you, but don't pig out.

"Portion control cannot be stressed enough," said Jaclyn London, senior clinical dietitian at The Mount Sinai Hospital. "Just don't exceed the one-ounce portion."

Want More Antioxidants? Try Apples »

Picking the Healthiest Chocolate

Here are a few guidelines for choosing chocolate that melts your heart.

  • Pick a dark chocolate with at least 70 percent cacao.

“The higher the cocoa content of a chocolate bar, the higher the flavonoid content and, more importantly, the lower the sugar content,” Bellatti said. Make sure cocoa appears before sugar on the label’s list of ingredients.

  • Unsweetened cacao nibs, raw cacao powder, and unsweetened cocoa powder are considered 100 percent cocoa, Bellatti said.

Products with a cocoa percentage over 70 percent are considered dairy-free—something else that’s good to know.

  •  Go for organic chocolate, Bellatti said.

“Cocoa beans have some of the highest pesticide loads of any crop,” Bellatti said. Due to weak regulations in countries that produce cacao beans, pesticides banned in the U.S. are still used in conventional cocoa farming.

  •  Avoid “alkalized” or “Dutch-processed” cocoa.

“It’s not that alkalized chocolate is ‘bad’ for you, but rather that the processing significantly decreases the amount of healthful antioxidants and flavonoids that you get in unprocessed cocoa,” Bellatti said, adding that some of the most processed cocoa products contain alkalized cocoa.

Learn How Chocolate Eaters Have Less Central Body Fat »