Birendra B. Adhikari, Pooran Appadu, Vadim Kislitsin, Michael Chae, Philip Choi, and David C. Bressler.
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
Bovine Spongiform Encephalopathy (BSE) or “Mad Cow Disease” is a neurodegenerative disease caused by high concentrations of misfolded proteins, called prions, in cattle. The bovine tissues that potentially contain high concentrations of prions are collectively termed as Specified Risk Materials (SRM) and include the skull, brain, eyes, tonsils, spinal cord, dorsal root ganglia, and distal ileum. As a result of the Mad Cow Disease scare in 1997, several countries prohibited the use of these animal tissues as cattle feed. In 2007, Canada implemented an improved feed ban eliminating SRM from all animal feed, pet foods, and fertilizer applications. This enhanced feed ban led to disposal of several million tons of SRM by incineration or land filling with considerable economical and environmental impacts. The environmental risks, combined with significant losses in profitability of the rendering industry required development of immediate and economically viable solutions for converting such materials into value-added products. From this perspective, the objective of this research is adding values to SRM by transforming them to materials suitable for technical applications.
To achieve the goal of converting SRM to high-value materials, we thermally hydrolyze the SRM according to a protocol approved by the Canadian Food Inspection Agency that is harsh enough to destroy any prions that may be present. The peptides recovered from the SRM hydrolyzates are then evaluated for the potential use in non-food applications. In one of our several approaches, such peptides are converted to protein-based binders for production of torrefied wood pellets, which are high energy density, carbon-neutral energy resources with potential for immediate and practical replacement of coal. Development of SRM-based binders for this purpose would not only bring value back to the livestock industry, but it would also bring the biomass energy and livestock industries together to address current challenges.