Three focus areas:gluten, starch, and straw

By Tracy Sayler

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Prairie Grains is the official publication of
the Minnesota
Association of
Wheat Growers,
North Dakota Grain Growers Association,
South Dakota Wheat, Inc., and the Minnesota Barley Growers Association.

Food will always be the major focus of wheat production. Wheat is the staple food of about 35% of the world’s population. Only a fraction of U.S. wheat production—less than 5%— is currently used for industrial products, according to the Minneapolis-based Institute for Local Self-Reliance (ILSR).

Still, the search for new uses of wheat is moving beyond the research and development phase and into commercial channels. There are three focus areas: gluten, starch, and straw.

The physical attributes exhibited by wheat gluten and wheat starch set wheat apart from all other cereal grains. The ability of wheat gluten to form an elastic mass when hydrated, to generate films that can be expanded, to form stable structures when heated, and to absorb and hold water puts wheat into a class of its own. Wheat starch also possesses unique attributes, particularly when compared to corn. Its whiteness, granule shape and size, ability to form strong and elastic gels and gelatinize at a lower temperature enables wheat starch to be preferred for a number of end uses.

Technological advancements in recent years have also made the production of wheat gluten and wheat starch more economical, with better product yield and lower manufacturing costs. Theoretically, opportunities for expanding wheat utilization beyond its traditional use in bread products abound. These opportunities have met obstacles in the marketplace, however.

The marketability of wheat starch is limited by the fact that corn is cheaper, and because the market for corn starch is more established. In the case of gluten, market potential has been handicapped by cheaper gluten imported from the European Union (explained more in-depth on page 14).

Changes in trade policy, and continued R&D of the wheat starch market, will do much to improve the market potential for wheat gluten and wheat starch. Right now, however, the biggest star in the new-use spotlight might not be the wheat kernel, but wheat straw.

Straw the new-use star

There is a growing recognition that straw residue has value, and more wheat producers are focusing on straw to get a higher value from the crop.

A study in 1997 by the National Association of Wheat Growers Foundation indicated that the use of straw in building material applications holds great potential, which can offer direct value-added returns to growers. While wood prices and the demand for particle board are rising, the technology of using wheat straw to replace wood-based materials is improving, and the market for straw-based building materials is becoming more established. Straw board holds a screw better than many wood-based materials, and is lighter and easier to transport.

A new industry devoted to manufacturing straw-based building materials has sprung up. Iso Board, based in Winnipeg, Man., Agriboard Industries, Electra, Texas, and Prime Board, Wahpeton, N.D., are among a handful of North American companies already in operation. Even lumber companies such as Boise-Cascade and Willamette Industries are exploring the use of straw as a partial replacement for wood-based materials.

"Sales are continually growing. It takes time for buyers to become comfortable with it and accept the product. It’s been an educational period, because the market hasn’t had an alternative to wood products that wheat board offers," says Kevin Smith, sales manager of PrimeBoard, which began production in July 1995 and now has 65 full-time employees. Prime Board products—consisting of 97% wheat straw—are laminated with veneer, cut into different shapes, and used to make furniture, counter tops, store fixtures, and other components. The bulk of the company’s products are used in the Midwest, but sales have extended to Texas, California, and the East Coast.

Kansas-based Harvest Board International (HBI) announced in January that Lisbon, ND has been chosen as one of three new sites for plants to manufacture composite board made from wheat straw. The others will be in Alberta, Canada, and Rawlins County, Kan. Construction will begin on the $50 million plant this spring and is expected to be completed by spring 2000. The Lisbon plant is expected to create up to 60 jobs initially, with a average payroll of about $1.9 million. The project is expected to inject over $5 million into the local economy.

With the completion of the plants, HBI will be the largest manufacturer of agrifiber board in the world, says David Hulshof, the company’s chief operating officer. HBI Vice President Jim Baker said in a December, 1998 Progressive Farmer article that nine customers have already committed to buying 80%, or 182 million square feet, of the output from the first three plants. One customer, Hallmark Cards, will use Harvest Board panels in retail shop displays.

In the manufacturing process, straw is chopped finely and compressed into particle board using MDI resin, a strong chemical adhesive. Since wheat gluten has excellent properties as a strong bonding agent, industry watchers say wheat gluten could someday be used in the straw board manufacturing process, resulting in natural building materials made entirely from wheat.

Spinning wheat straw into plastic

Wheat straw can also be used to replace some of the petrochemicals and fillers used in the production of plastics. After several years of research, Donna Johnson, president and biochemical engineer at Pinnacle Technology, Lawrence, Kan., working with USDA’s Forest Products Laboratory, Madison, Wisc., have perfected a method of combining processed wheat straw with either polypropylene or polyethylene that can be used to make many plastic products including business card holders, extruded lumber, downspout splash guards, boat seat mounts, interior automotive panels, garbage pails, tool handles, flower pots and more.

"Agro-Plastic" is what she calls the plastic, which contains 50% wheat straw filler.

Few plastic products use just plastic; fillers such as calcium carbonate, mica and talc are commonly used. In 1993, the total weight of fillers used in plastic production was 7.7 billion pounds. Replacing just 1% of the North American polypropylene market would require 12 manufacturing plants. Expanding into the polyethylene market would require an additional 24 plants. Thus, replacing a very small percentage of the fillers with wheat straw presents a tremendous opportunity, says Johnson, who has spent years perfecting ways to incorporate wheat straw into the production of consumer goods using machinery commonly used by the industry.

Wheat straw is beneficial as a filler component in plastic. Cost is comparable with other fillers. Less material is used, resulting in reduced product weight and reduced shipping costs. From a manufacturing standpoint, there is reduced wear and tear on product molds with wheat straw filler. Manufacturing temperatures can also be reduced using wheat straw, cutting manufacturing costs. Tests also indicate that some plastic products using wheat straw could be produced 10 to 25% faster.

"Since straw is lighter (than traditional fillers) there is about 20% less material used and shipping costs will be less. We think there will be a lot of advantages to it," she says. "You can use wheat straw in many standard plastics."

Johnson says Pinnacle plans to license the Agro-Plastic technology, and allow interested manufacturers to make products under a royalty agreement.

More information about wheat straw-based plastic can be found at Pinnacle’s web site at www.pinnaclet.com. An "Agro-Plastic Market Analysis Final Report" may by found at www.west bioenergy.org, the web site for the Western Regional Biomass Energy Program, which helped fund the wheat straw research.

This opportunity of utilizing wheat straw is a prime example of a growing interest in what the ILSR calls "The Carbohydrate Economy." Speculating in one of its newsletters, the ILSR said that "In the near future, tree-free fibers may well come from the enormous pool of agricultural residues. Some 350 million tons of agricultural cellulosic residues can be economically and environmentally recovered—cornstalks, rice and wheat straw, and other materials. Will the next great American forests be located in the Midwest?"

Potential new and higher value non-food uses for wheat

Biodegradable plastics
Straw-based building materials and wood substitutes
Biodegradable kitty litter
Acoustic tiling
Adhesives for paper and wood products
Alternative to caseinate, soy isolates and egg whites in food products
Antidote for lead poisoning
Anticorrosive in paint, lubricants
Biodegradable films, coatings
Body powders
Building insulation
Capsules for medicines
Car body paneling
Carbonless copy paper
Concrete
Cosmetics, skin care products
Dishwashing laundry detergent
Pharmaceutical products
Fertilizers
Imaging agents for X-rays
Ink additive
Insulation for refrigerators and greenhouses
Medical diagnostic tests
Milk replacer
Nasal sprays
Pesticides
Plastic pellets for injection molding
Polymers, resins
Reinforcing agents for rubber products
Sandblasting grit
Paper
Scavenger in toxic waste disposal
Sizing, coating for paper, textiles
Biodegradable eating utensils and food containers
Ethanol (about 3% of ethanol produced in the U.S. is made from wheat)

Sources: Milling and Baking News, NAWG Foundation