What are McDonald's fries made out of? An engineer investigates in new ad

McDonald's is trying to fight its "pink slime" reputation, one menu item at a time.

The fast food restaurant's latest commercial addresses the rumor that their fries are not made from real potatoes. In the ad, a McDonald's employee takes Grant Imahara (of "Mythbusters" fame) through their factory, showing the fry creation process in reverse.

Tap to watch if you're viewing on the news app.

1. Real potatoes: McDonald's said the first step is to bring real potatoes off the trucks and into the factory.
2. Potato cutting: Potatoes are fired 60-70 miles per hour through a machine that gives it the fry shape.
3. Ingredient dip: Chemicals are added so the fries maintain their color, including dextrose (a sugar).
4. Partial frying: This initial frying gives the fries a crisp outer shell.
5. Freezing: The fries go through a "freezer tunnel" so they can be transported to the stores, where the frying process is completed.

If this video leaves you with a burning question ("But what's in them?"), the company posted another video listing the ingredients. The company said there are 19 ingredients, with potatoes being the first ingredient. Many of the other ingredients are oils and chemicals needed to make the process described above run smoothly, the video explained.

One of those chemicals is sodium acid pyrophosphate, which preserves the fries while they are frozen. An FDA study found that this ingredient is generally recognized as safe, though it recommends limiting intake.

Both ads are part of a new campaign called "Our Food, your questions" that responds to customers' questions. McDonald's hired the "Mythbusters" star to be a part of the campaign.

An earlier video in this campaign, which explained the process behind making chicken nuggets, is the company's most popular video on YouTube, with more than 6 million views. That video, however, has a ratio of three likes for every dislike, with customers calling into question whether the ad was representing the truth.

The potato-to-fry explanation is poised to receive similar attention: It has more than 1.8 million views in one day.

Does knowing this process make you any more or less likely to eat fries from McDonald's? Let us know in the comments.