New and Ongoing Research Needs Identified

By Annel K. Greene, PhD, Center Director
Clemson University Animal Co-Products Research and Education Center

The Animal Co-Products Research and Education Center (ACREC) Research Committee and Governing Board spring meetings were held at Clemson University in late February and early March where rendering personnel reviewed 15 project pre-proposals submitted in response to a request for pre-proposals (RFP). Earlier this year, the Fats and Proteins Research Foundation (FPRF) answered ACREC’s request for specific topic areas of most critical need for the industry and a targeted RFP was developed from the list.

The three highest priority needs for the industry were identified as: (1) ways to resolve the polyacrylamide problem in dissolved air flotation; (2) validation of pathogen destruction (bacterial, viral, parasitic) via rendering processing; and (3) new antimicrobial products to apply to finished animal protein meals to prevent pathogen growth in case of recontamination. A list of other lower priority issues were included in the RFP and included such topics as improved odor remediation, new markets, reduction in processing costs, and reducing free fatty acid levels in rendered animal fats.

In response to the RFP, Clemson University researchers considered the research problems and prepared pre-proposals suggesting projects to address the industry’s needs. During the ACREC Research Committee meeting, renderers and researchers discussed the proposed projects one-on-one to fully understand the procedures and the anticipated outcomes of the research. National Renderers Association (NRA)/FPRF staff members, seven FPRF renderer members, and three guests from the Poultry Protein and Fat Council were present at the meeting. Previously funded researchers discussed the progress of their current projects and 15 new pre-proposals were presented by familiar faces and new researchers.

Among the discussions was exciting news delivered by Dr. Scott Husson who has been working on membrane systems. These newly developed membranes can be used to eliminate the use of polyacrylamide in wastewater treatment. Husson’s membranes have surfaces that limit fouling and enable chemical-free cleaning. Perhaps the most telling part of his presentation was that he has been unable to “foul” the membranes in order to conduct experiments on how to clean them. The membranes are very resistant to clogging and therefore should have a long lifespan in industrial use. Husson and his team are using oily wastewater derived from rendering plants in their experiments.

Dr. Andrew Hurley’s team is making good progress examining different polymers for use as collection container liners as an alternative to polyethylene. Hurley and his team are examining various natural-based polymers and are subjecting these to rendering cooker conditions to determine how each will react during rendering processing. The ultimate goal of this study is to eliminate polyethylene and its problems from rendering systems.

Dr. Charles Gooding detailed his work with 50 senior undergraduate Chemical Engineering students to develop chemical process flow sheets for converting rendered fat into higher value products. The student teams will submit their final written reports soon and make team presentations in April. Gooding has invited members of the rendering industry to attend the presentations. If interested, contact him at

In a separate project, Gooding also has been asked to develop a life cycle assessment for rendering operations. Previously, Gooding conducted work to develop the interactive spreadsheet carbon footprint calculator for rendering operations that is now available for use by NRA and FPRF members. According to Gooding, “The goal of this project is to demonstrate through life cycle assessment that rendering is the most environmentally acceptable method of handling animal by-products and that the products derived from rendering are as green as similar plant-based materials. If this goal can be achieved, the results will help the industry to protect itself from unwarranted criticism. These results could also lead to increased opportunities for rendering companies to collect raw materials and expand production capacity.” Earlier work by ACREC researchers Dr. David Bruce and Dr. Dora Lopez on life cycle assessment for biodiesel made from rendered fat will be useful in this new study.

Dr. Xiuping Jiang’s work on antibacterial bacteriophages against Salmonella and hydrogen sulfide producing bacteria is progressing and is scheduled to move into rendering plant testing in the near future. The bacteriophages are capable of rapidly decreasing populations of targeted bacteria through natural destruction processes. Bacteriophages are approved for use in foods and medical applications and are an effective means of controlling specific populations of bacteria.

Dr. Christopher Kitchens’ work on improved methods of removing fat from animal protein meals is progressing nicely. He is able to reduce the fat content from approximately 14 percent down to one to two percent using a tunable procedure. Removing the higher value fat would increase the volume of fat renderers could sell. Also, reducing fats in protein meals could become a selling point for low-fat animal diets, especially for pets. Removing the fat also would allow potential for re-mixing diets with specific compositions.

Dr. Alexey Vertegel and Dr. Vladimir Reukov are continuing their work on natural antioxidants and report excellent results in comparison with currently used products. As stated in the progress report, their work is to “prevent lipid oxidation thus preserving nutritional value and palatability.”

Dr. Annel Greene and Jiang along with PhD graduate student M. Melissa Hayes and statistician Dr. William C. Bridges Jr. are continuing work on thermal death time of Salmonella in rendered animal by-products. Validation that the temperatures and times used in rendering cookers are sufficient to kill pathogens is an ongoing quest to meet increasing regulatory questions.

Two of the new faces at the ACREC meetings were Dr. Daniel Whitehead of Clemson’s Department of Chemistry and Dr. Frank Alexis of the Department of Bioengineering. They proposed an exciting project to develop the next generation strategy for odor remediation. Using advanced nanotechnology chemistry, their proposed project is anticipated to reduce odors in rendering plant environments and in trucks through biodegradable and non-toxic means. Whitehead and Alexis indicated their proposed method could have “potential use in rapid deployment in emergency/spill situations” as well as be useful with existing odor remediation systems.

Other proposed projects included methods to destroy polyacrylamide in wastewater, alternatives to use of polyacrylamide, use of residual water and nutrients from wastewater, and various antimicrobial products for use in rendered protein meals.

The researchers involved in the current ACREC projects represented three different colleges at Clemson University and nine departments. Disciplines included microbiology, chemical engineering, environmental engineering, chemistry, bioengineering, packaging science, and others. FPRF’s Dr. David Meeker said of the project pre-proposals, “This session’s set of proposals was outstanding overall. The center concept is really starting to pay off. We have a critical mass of knowledge and researchers with a good understanding of our industry and its challenges. Our increasing FPRF interactions on priorities have also helped guide the direction of the center.”

During the ACREC Research Committee meeting, the researchers discussed each proposed project with the FPRF members and other visitors. The renderers then met in closed session to determine which of the proposed projects would best fit the industry’s needs. After the closed door discussions, projects were selected and await contract and funding finalization.

ACREC and FPRF are jointly requesting any additional priority research areas so efforts can continue to be directed toward the industry’s needs. If you have a research area you would like ACREC to consider, please e-mail your topic to Greene at and/or Meeker at

April 2012 RENDER | back