Researchers at Virginia Tech have discovered new uses for the waste byproducts of beer brewing, including food proteins and biofuels.
Beer has seen a major surge in popularity in the US in recent years, with craft brewing leading the way and challenging some of the old stalwarts. There has also been a corresponding increase in waste byproducts, 85% of which is grain. The spent grain byproduct is roughly 30% protein and 70% fiber.
Traditionally, the spent grain is sold off as cattle feed, or dumped in landfills. It is not used for human consumption due to the high-fiber content making it difficult to digest. Nonetheless, with 30% protein, researches believed it represented a lost opportunity.
“Spent grain has a very high percentage of protein compared to other agricultural waste, so our goal was to find a novel way to extract and use it,” says Yanhong He, a graduate student at Virginia Polytechnic and State University (Virginia Tech).
Haibo Huang, Ph.D., the project’s principal investigator, and He developed a wet milling fractionation process that allowed them to recapture up to 83% of the spent grain’s protein. By eliminating the high-fiber content, the protein concentrate can be used as a food source.
There is also hope of taking the fiber-rich waste and turning it into biofuel. Specifically, Huang’s postdoctoral researcher Joshua O’Hair, Ph.D., found “a new species of Bacillus lichenformis in a spring at Yellowstone National Park.” The bacteria is capable of converting sugars to 2,3-butanediol. When the fiber-rich waste was treated and broken down into sugars, the researchers were able to product 2,3-butanediol using the bacteria.
The research is a promising development for the brewing industry, one that could have far-reaching impacts.