–by Ranae Jorgenson, AURI Analytical Chemist
Could corn used for fuel, also be used for food? Hans van Leeuwen thinks so.
Coproducts left over during ethanol production are currently used to add nutrition to livestock diets, and now researchers are looking at ways to create a nutritious supplement for humans from this process. In a recent project I had the honor to work with Hans van Leeuwen, Ph.D., an Iowa State University professor, as part of his research team that is looking at creating a new food supplement with products leftover from processing corn into ethanol. His product, called MycoMeal, contains valued amino acids found in meat and could help provide an affordable, highly nutritious supplement to those suffering from malnutrition.
MycoMeal is a product created by cultivating edible fungus (there are other edible fungi in the world including mushrooms, porcini and truffles) on thin stillage from corn-to-ethanol plants. The process of growing the fungus also cleans water from ethanol production so that it can be recycled back into fuel production. This water reclamation process earned the research team the Global Award for Applied Research in the 2012 International Water Association Global Project Innovation Awards. The International Water Association (IWA) established the Project Innovation Awards to recognize excellence and innovation in water engineering projects throughout the world. Only six global awards are given every two years, and before competing on the international level, projects go through a rigorous preliminary round through affiliated organizations worldwide.
While the research is primarily being conducted at Iowa State, here at AURI’s analytical chemistry lab in Marshall, Minn. I analyzed MycoMeal’s nutrient composition for components such as protein, fat, minerals and fatty acids. The opportunities presented through this process are important to Minnesota ethanol plants because they present ways to make ethanol production more economical.
Here’s a quick overview of how the process works:
For every gallon of ethanol produced, there are about five gallons of leftovers known as stillage. The stillage contains solids and other organic material. Most of the solids are removed by centrifugation and dried into distillers dried grains that are sold as livestock feed, primarily for cattle.
The remaining liquid, known as thin stillage, still contains some solids, a variety of organic compounds and enzymes. Because the compounds and solids can interfere with ethanol production, only about 50 percent of thin stillage can be recycled back into ethanol production. The rest is evaporated and blended with distillers dried grains to produce distillers dried grains with solubles.
The researchers add fungus to the thin stillage and it feeds and grows into a thick mass in less than a day. The fungus removes about 60 percent of the organic material and most of the solids, allowing the water and enzymes in the thin stillage to be recycled back into production.
The fungus is then harvested and dried as animal feed that’s rich in protein, certain essential amino acids and other nutrients. It can also be blended with distillers dried grains to boost its value as a livestock feed and make it more suitable for feeding hogs and chickens.
Van Leeuwen says the production technology can save United States ethanol producers up to $800 million a year in energy costs. He also said the technology can produce ethanol coproducts worth another $800 million or more per year, depending on how it is used and marketed.