|
Getting your Trinity Audio player ready...
|
North Carolina may be famous for its beaches and Blue Ridge Mountains, but the state has a lesser-known claim to fame. As the sweet potato capital, North Carolina grows 60% of the country’s supply—and, according to Appalachian State University, leaves 63 million pounds of the root vegetables to rot in the fields each year.
Brett Taubman, a professor at App State, wants to milk those unused sweet potatoes for all they’re worth. He and his team recently received a $1.82 million NCInnovation grant for Rootsii, a startup that makes plant-based milk out of that torrent of tubers.
An analytical chemist by training, Taubman said he had always been interested in “foods and flavors.” That is, brewing science and fermentation.
“It just kind of struck me, like, why is there not a plant-based milk made from sweet potatoes?” Taubman said. “They’re just absolutely loaded with starch, and they’re delicious and nutritious, and it just seems so obvious.”
Taubman expects Rootsii’s milk—which, in photos, has an orange tinge—to reach markets within the next two years, and he hopes to later expand to products like yogurt, ice cream, and soy sauce.
The Assembly called Taubman to learn more about this first-of-its-kind sweet potato milk.
This Q&A has been edited for length and clarity.
Sixty percent of the country’s sweet potatoes are grown in North Carolina, but up to 40% of those go to waste. Why is that?
The USDA has a very strict grading system for sweet potatoes, and only the highest-grade sweet potatoes—the ones that are the right size, the right shape, aren’t weird looking—those are the ones that are actually sold as sweet potatoes in the grocery store. A little bit lower grade, those can be turned into puree for baby food, pet food, canned sweet potato puree, things like that. And then anything below that, they’re just left in the field to rot.
So that’s where I think a lot of the remainder of that loss can come from, is the fact that they’re just left to rot in the ground, because they’re not currently worth the time and effort to actually harvest those. Those are the ones that we want to take advantage of, by using those ugly discards.
How do those sweet potatoes that are left in the fields end up with you and your lab?
I’m probably oversimplifying this, but we’re assuming that those sweet potatoes that are currently left to be discarded or just left to rot in the field, those can be sorted into bins for us. So it should be adding one more step to the process during that harvest that is already occurring. So I don’t think it will be too much of a heavy lift for the farmers, and I think as long as they can stand to benefit from the fact that we’re using those sweet potatoes and getting paid for those sweet potatoes that they’re currently leaving to rot in the fields, I think it will benefit everybody.
What’s the process to make sweet potato milk?
It takes very good grip strength because you really just have to squeeze those sweet potatoes. No, just kidding.
We take the sweet potatoes, we break them up a bit, we gelatinize the starches—so you have to heat them up. Gelatinizing the starches is a fancy way of saying that, effectively, you’re loosening up those starch molecules to allow the enzymes to actually access those starches and degrade them. …
We also introduce chia seeds to add fiber and protein to the mix and also thicken it up, adding a creaminess to our sweet potato milk. We’re adding a yeast-derived protein as well, so that our milk actually has protein content, which is what a lot of plant-based milks currently lack. And then we add oil in with the rest of the solution, so it makes a nice creamy plant-based milk and a nice creamy mouthfeel that is very similar to regular dairy milk.
What does it taste like? Is it sweet?
It is probably the best thing you will ever put in your mouth. Besides that, it’s pretty neutral-flavored, like milks should be, in my opinion, but it does have a hint of sweet potato in there. I think, if you tried it on its own and didn’t know that it was derived from sweet potatoes, it would be difficult to pin down, which is what we want.
What is the nutritional value, especially compared to other types of milk?
Sweet potatoes are naturally high in vitamin A, potassium, magnesium, dietary fiber—lots of really good nutritional qualities in a sweet potato that we are extracting into the milk. Then we’re adding a yeast-derived protein, as I mentioned before.
One of the things that we’re trying to do is to match the nutritional values of cow milk, particularly for things like protein and vitamin A, vitamin D, calcium, things like that, where we really want to get this product into institutions like K-12 schools, university dining halls, hospitals, as a plant-based alternative to dairy milk for folks that are lactose intolerant. Our product is also gluten-free, it’s nut-free, it’s pretty much any major allergen-free. Plus, it’s a clean label product, so it should appeal to the widest demographic base possible.
What’s the environmental impact?
We did kind of a back-of-the-envelope calculation and figure that it takes about a tenth of the water to produce our sweet potato milk as it takes to make the average almond milk. Beyond that, because we’re using the ugly discards that are currently just being left to rot in the field, we view this as one of the most sustainable products that could possibly be made.
What other types of products are you thinking of creating?
We’ll have a more sweetened version, we’ll have flavored versions, and things like that. But also, some of the initial offerings that we want to have are coffee creamers, so sort of an unflavored half-and-half type of product, as well as some flavored versions. Of course, we have to come out with the pumpkin pie spice one to compete with Starbucks in the fall, but you know what goes better with pumpkin pie spice than sweet potatoes, so that’s a no-brainer. And then also ice cream, so those are kind of the initial three products.
What do you see as the future of sweet potato milk, and where do you see the plant-based milk industry heading?
I’ll start with the latter half of that question, and you know, introduce the market for plant-based milks, which is already huge. I mean, globally, it’s already valued at over $20 billion and it’s forecasted in the next 10 years to almost double in that value. So, the plant-based milk industry is already huge, and it’s growing rapidly. There’s a lot of room for growth in that sector already, and we estimate that we can absolutely earn a significant share of that plant-based milk market. Even if we capture somewhere in the 1 to 5% market share of that plant-based milk market, which we feel like is reasonable, it could be huge. It will be a huge boon for the state as well, you know, we’re talking potentially hundreds of jobs, millions of dollars in state tax revenue. So this could be very big for the state of North Carolina.
