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‹‹‹ Contents page for this issue     |    Summer 2015

Crafting a new market

This isn't just cattle feed. Brewers' spent grain may reap environmentally friendly capsules, coatings, and food additives

By Susan Trulove

When Asheville, North Carolina, became a craft beer mecca, the region’s economic development leaders and brew fans alike were pleased. Tourists flock for a whiff of suds, a cool swallow, and a taste — or many tastes — of nirvana.

Sixteen craft beer brewers were operating in the area as of spring 2014. One of them, Highland Brewing Company, is expanding its operation by 50 percent. And it isn’t just small, local breweries that make Asheville their home.

Nationally known New Belgium Brewing of Fort Collins, Colorado, will begin operations in Asheville by the end of 2015, producing its Fat Tire beer and 1554 beer and experimenting with other products.

Even the local cattle are happy as they slurp and munch brewers’ spent grain, which is the residue left after sugar is removed during the brewing process. It is the major byproduct of beer making.

And there is so much of it, there may not be enough cattle in western North Carolina — or in the region that includes eastern Tennessee and far Southwest Virginia — to consume the 150 to 400 tons per day of spent grain that the breweries will generate.

These are the Smoky Mountains, after all, more known for mountain music, hiking, and fishing — not cattle country.

Excess spent grain has to be hauled to far-away dairy cows, beef cattle, and bison, with the sale price of about $50 per ton hardly covering transport costs. And it has to be moved quickly; the material ferments and must be consumed within seven days.

Enter Virginia Tech natural product researchers Young Teck Kim and Scott Renneckar, and entrepreneur Greg Cumberford, president of Bent Creek Institute, a nonprofit business incubator affiliated with the North Carolina Arboretum.

“Brewers’ spent grain is a rich resource, with about 30 percent protein and 20 percent cellulose, which could be used in human food and pharmaceuticals,” said Kim, an assistant professor of practice in the College of Natural Resources and Environment’s Department of Sustainable Biomaterials. “All we have to do is extract them, and we know how to do that.”

Brewers’ spent grain, like many agricultural byproducts, has the advantage of having already been harvested, transported, and initially processed, according to Renneckar, an associate professor of wood science who recently joined the faculty at the University of British Columbia.

“It is potentially worth much more than $50 per ton as cattle feed,” said Cumberford.

Friendly packaging

Kim approached Cumberford in 2012 with the idea that Virginia Tech and Bent Creek Institute develop a new dietary cellulosic material from agricultural byproducts.

Organically certifiable dietary cellulose could be used in human pharmaceuticals and foods with health additives, for which there are markets worldwide, according to Cumberford.

He is a 20-plus-year veteran of the natural products industry with experience in botanical products formulation, horticulture, manufacturing, branding, and distribution.

Kim had a pretty good idea about how to extract the cellulose and protein.

He had previously developed novel versions of bioplastics to create 100-percent natural, biodegradable plastic for rigid containers. The plastic is now being used by Gaia Herbs of North Carolina, which funded Kim’s original research, to bottle organic dietary supplement products.

“Their customers are willing to pay a little extra for environmentally friendly packaging,” said Kim.

However, this bioplastic was not ready for human consumption because some harsh chemistry was used in the extraction process.

Then, in discussion with Renneckar, Kim learned of a natural ingredient that could replace the harsh chemicals in the process, resulting in cellulose and protein products that are entirely natural.

Renneckar, whose background is in bioenergy and biopolymer materials, and colleague Justin Barone, an associate professor of biological systems engineering associated with the Institute for Critical Technology and Applied Science at Virginia Tech, had developed a process to extract sugars from wood that could be used to create biofuels.

“I talked to (Kim) about it and he thought it was a good fit for what he was doing,” Renneckar said.

“It is a sustainable manufacturing process, called melt compounding technology, capable of minimizing the use of strong toxic chemicals to extract cellulose from agricultural byproducts,” Kim said. “It can be applied to any biomass in nature, which has been often considered as waste, to isolate individual components such as cellulose, lipids, and protein.”

Separating the chaff

Together they crafted a proposal that was funded through Bent Creek Institute by New Belgium Brewing, Highland Brewing Company, and a number of North Carolina public entities, including the Biofuels Center of North Carolina, the North Carolina Department of Agriculture, and the Biotechnology Center of North Carolina.

“We were proposing a process that could take brewers’ spent grain, transport it perhaps 10 to 15 miles to a processing site, and address an unmet market need for organically certifiable dietary cellulose,” Cumberford said.

One use for the resulting cellulose is as functional dietary fiber, such as in gluten-free food products and to enhance low-fiber foods.

Other Food and Drug Administration-approved uses are as a fat substitute in low-calorie foods, as a viscosity moderator “so your ketchup is not runny,” said Renneckar, and as an emulsifier “so the oil and vinegar in your salad dressing won’t separate.”

If modified further, the powdered cellulose can be used to make capsules for medicines or supplements; edible coatings to attach seasonings to crackers, tablets, candies, and many other products; and a moisture barrier, Renneckar said.

Protein derived from spent grain has advantages as well.

“Plant-based proteins solve several problems associated with animal protein, such as for people who do not eat meat in any form and people who wish meat products to be kosher,” said Kim.

The process that separates cellulose and protein from spent grain is simple, based on various operational parameters, such as temperature and pressure, and the ingredient Kim learned about from Renneckar — a byproduct of one of his and Barone’s biodiesel projects.

It looks like the manufacturing process that is used to create plastic products.

Biomass, such as brewers’ spent grain, is fed into the extruder with the vegetable oil byproduct. Heat and pressure are applied, and the simple mixture of fractionated individual components comes out.

“In our process,” said Kim, “it accelerates the division of individual components in the biomass under controlled processing conditions.”

“This specific ingredient protects the plant material from being broken down too much,” said Renneckar. “And, as production of biodiesel increases, there is a world surplus of this increasingly valuable food-grade byproduct, which is also a byproduct of a vegetable oil.”

The mixture is processed into cellulose and protein using either enzymes or oxidation.

“The process will meet the U.S. Department of Agriculture’s guidelines for organic labeling claims in dietary cellulose and capsule materials because it is clean, green, and eco-efficient with virtually zero wastes, especially compared to wood and genetically modified cotton feedstocks,” Cumberford said.

Two patents are in the works — for the pretreatment that Renneckar and Barone discovered and for Kim’s unique melt compounding process — and a new business has launched.

OrganiCel LLC, a division of Bent Creek Botanical Technologies Inc., licensed the processing technologies from Virginia Tech Intellectual Properties “and will apply the Virginia Tech technology to food-grade feedstock so that dietary cellulose will be from an edible byproduct,” said Cumberford.

Technology transfer, naturally

Dietary cellulose currently used in the food and pharmaceutical industries is derived mostly from wood, a source not associated with human food.

“Cellulose from wood requires an industrially intensive production process that uses some heavy-duty chemistry that is often toxic to the environment. The result is not organically certifiable in the U.S.,” said Cumberford. “Our product is all-natural and thus overcomes organic labeling objections previously stated by the National Organic Standards Board.”

“There are no organic cellulose products for food and pharmaceuticals,” said Kim. “Most plant-based vegetarian pill capsules are not certified organic because strong chemicals were used to separate the cellulose from the plant materials.”

In addition to dietary fiber and capsules, the natural cellulose can be adopted into a wide spectrum of industrial products, such as paper, film, toner, ink, and paint, said Kim.

But there have not yet been commercial commitments, said Cumberford.

“The first year’s research was about proof of principle — proving that we can produce cellulose in an efficient and green manner,” he said.

OrganiCel has identified a facility near Asheville and is seeking early-stage capital to begin equipment installation to enter the second phase — pilot-scale production of the first organic plant-based cellulose products.

In the Asheville area, brewers’ spent grain will be used to extract cellulose and protein. In Virginia, potential feedstocks could be switchgrass, tobacco stems, and canola seed meal from which oil has been processed. Phase three will be technology transfer.

“We will be selling products and licensing the OrganiCel process technologies to suitable companies, as validated by Dr. Kim,” said Cumberford. “The companies can operate the technology themselves or engage OrganiCel LLC to operate the technology for them.”

Consumers will benefit by having purer food products, but who profits?

“Ideally, we want to preserve rural agricultural land and create another green products manufacturing sector for our region, so we want to create a model that returns a share of the yield back to growers and feedstock producers,” said Cumberford. “There is a more than billion-dollar market worldwide for gluten-free foods that are organic, as well as other uses for organic dietary cellulose and plant-based protein.”

Brewers’ spent grain, tobacco stems, and canola seeds are just the beginning. Many food and botanical products generate millions of tons of byproducts, such as bulky pulp from juices, apple pulp, vineyard waste, and potato peels.

It may be something to think about over a beer.


Photo by Jim Stroup.

Variations in grain source, malting, and malt drying are a few of the many factors that result in different kinds of beer. After the spent grain is removed — destined now for new, exciting products — there are additional steps in the beer brewing process.

Scott Renneckar adds ingredients to the extruder in the small Virginia Tech lab used when the research project began.

Young Teck Kim purifies “edible cellulose” extracted from brewers’ spent grains.

“Brewers’ spent grain is a rich resource, with about 30 percent protein and 20 percent cellulose, which could be used in human food and pharmaceuticals. All we have to do is extract them, and we know how to do that.”
— Young Teck Kim