Last year, Whole Foods recalled two kinds of curried chicken salad that had been mislabeled and sold in some of its stores.

The salad made with real chicken had been labeled as vegetarian "chick'n" salad while the salad supposedly made with a meat alternative contained actual chicken.

"None of the customers apparently noticed the difference," Ethan Brown, founder of Beyond Meat, which made the chicken substitute, told the New York Times.

vegetarian meat alternativesAs demand for meat alternatives has increased — driven by health, environmental and animal-welfare concerns — the industry has attracted big-name investors, including Bill Gates and the founders of Twitter.

In 2012, sales of faux meat products hit $553 million, according to market research firm Mintel.

The taste, texture and variety of meat alternatives has improved, and today consumers can purchase not only a variety of veggie burgers, but also everything from imitation shrimp to meat-free buffalo wings.

And many people can't tell the difference between animal and vegetable protein.

"I served Boca burgers to my family one night, just to see if anyone would notice a difference," said Knoxville, Tennessee, resident Amanda Martin. "No one did. It wasn't until after dinner and I revealed my secret did they know."

Faking it

How do manufacturers create vegetarian meat alternatives that can fool meat-eating families and even a New York Times food critic?

For most faux meat products, the process begins with soy protein, or textured vegetable protein (TVP), in the form of powder.

The biggest challenge in creating a convincing meat alternative often boils down to texture. Soy protein is globular while actual meat protein is fibrous, so food manufacturers have to alter the soy's molecular structure.

This is typically done by exposing the soy protein to heat, acid or a solvent and then running the mixture through a food extruder that reshapes it.

"When you denature the molecules, they open up and become more fibrous," Barry Swanson, a food science professor at Washington State University, told Chow.com. "Then you hold them together with a gel, such as carrageenan or xanthan gum, something that will hold a little bit of water, and what you get is something that vaguely resembles a piece of meat.”

But soy isn't the only way to create faux meat products. Some are developed from wheat gluten, which has a stretchy texture that can be easier to modify so it resembles the chewiness of meat.

coconut baconSome products, such as Quorn's meat alternatives, are made from a double-fermentation process that creates a fungus structurally similar to animal protein.

For other "meats," the process is far less complicated. Phoney Baloney's bacon is made from seasoned coconut flakes.

"We use coconut because it's a natural, healthy fat," said Andrea Dermos, co-owner of the company. "That means that it will crisp up and lend itself to the texture of bacon, as well as take in all of the seasonings that we marinate it in."

Tastes like chicken

One of the newest meat alternatives — which fooled even Mark Bittman, the New York Times' food columnist — is Beyond Meat, the aforementioned vegetarian "chick’n" used in Whole Foods' curried chicken salad.

Beyond Meat fake chicken"Chicken has always been the holy grail," Seth Tibbott, creator of Tofurky, told Time in 2010.

The proteins in Beyond Meat come from soy, yellow peas, mustard seeds, camelina and yeast.

The product (pictured right) took more than a decade to develop, but it has what food scientists call the "right chew," meaning it has the texture of meat. Beyond Meat's chicken strips, the creation of University of Missouri food researchers Fu-Hung Hsieh and Harold Huff, even shred like real chicken.

"It doesn’t taste much like chicken," Bittman wrote in his review, "but since most white meat chicken doesn't taste like much anyway, that's hardly a problem; both are about texture, chew and the ingredients you put on them or combine with them."

On their own, any unflavored meat alternative won't have the taste of actual animal flesh, but once food manufacturers have achieved that meaty texture, they can season the faux meat to mimic anything from hot dogs and ribs to steak and calamari.

Watch the video below to see how Beyond Meat's "chick'n" is made.