Odds are you've seen the word "whey" while walking grocery store aisles, commonly found in many health supplements and fitness protein bars.

It could have been from a quick glance at ingredients to your favorite salad dressing, a savory spread or protein bar that read, "This product contains whey." If you're a new parent, you might have reached for that fresh can of baby formula and found yourself reading the same words.

Today, this product is valued for its health benefits that come from its rich amounts of protein and its inclusion of essential vitamins and minerals. From aiding in patient recovery to nourishing infants, whey has become a staple ingredient in many food products and medical nutrition plans both in the U.S. and globally.

But what is whey, and how has it become an increasingly present ingredient in so many food and health products?

Jennifer Spencer, Ph.D., Texas A&M AgriLife Extension Service dairy specialist and assistant professor in the Texas A&M Department of Animal Science, Stephenville, shared her expertise on whey's past, present and future.

During the cheese-making process, the cheese curdles and creates a liquid byproduct known as whey, Spencer said.

"For decades and decades, cheese makers didn't know what to do with it," she said.

It was initially fed to animals as a protein supplement to help manage the surplus of product or it was discarded.

"However, in the early 2000s, scientists and the dairy industry realized the nutrient value that this once-overlooked cheese byproduct actually holds," Spencer said.

As it turned out, whey contained a high protein value and essential everyday vitamins and minerals that had been otherwise overlooked. Today, it's found its way into many foods at the grocery stores and has even been integrated into hospitals worldwide to enhance patient recovery.

Initially, whey was marketed for health and fitness-related products like powders, supplements, shakes, grab-and-go protein bars or prepackaged drinks. But over time, whey has become a prevalent ingredient in a wide variety of products that serve many purposes.

"The important thing to note is that whey and all the protein products that come with it are not just products fit for athletes," Spencer said. "They can also be instrumental in helping patients who may be getting out of surgery or those dealing with cancer who need to consume enough nutrients when they are not hungry."

Whey powder has also become an important nutritional ingredient in baby formulas in the U.S. and globally.

"This inclusion of whey in baby formula is significant for many reasons," she said. "Whey's addition provides consistent nutrients and much-needed vitamins and minerals for children. This is critical to the dietary requirements of babies, especially in parts of the world where access is limited."

The once cheese plant leftover has become valuable enough to be included in high-value protein products across the world, said David Anderson, Ph.D., AgriLife Extension economist and professor in the Department of Agricultural Economics, Bryan-College Station.

Whey has not only had a direct and tangible impact to the lives of consumers but has also proven its value through its economic impact within the dairy industry.

"As far back as the late 1990s, whey prices have shown an upward trend over this 25-year period," Anderson said. "We've gone from times when the stuff wasn't worth very much to it being a valuable product. Exports have been a real growth area for U.S. dairy products, including various milk and cheese powders, whey being one of them."

As exports have grown, products like whey have become more valuable simply because of the expansion in an international market, he said.

The long-term transformation that whey has taken from being a discarded byproduct to a well-rounded nutritional supplement speaks to the ever changing and evolving ways of agriculture, specifically within the dairy industry.

"It is obvious that whey now carries significant weight in the dairy industry because producers and consumers are getting so much value from it," Spencer said. "It adds value to each pound of milk for producers, but it is also something that consumers want and need."

So what's next for whey?

"I tend to think the future of whey is positive and one still ripe for growth," Anderson said. "While the consumer desire to increase protein consumption might slow or level off, I think we'll find new uses for whey in food products. I think whey product exports could also continue to grow in the future."