Formulation of a biodegradable, odor-reducing cat litter from solvent-extracted corn dried distillers grain

Authors: Vaughn, Steven; Berhow, Mark; Moser, Jill; LEE, E - Summit Seed, Inc

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/10/2011
Publication Date: 9/14/2011
Citation: Vaughn, S.F., Berhow, M.A., Moser, J.K., Lee, E. 2011. Formulation of a biodegradable, odor-reducing cat litter from solvent-extracted corn dried distillers grain. AAIC Annual Meeting.

Interpretive Summary:

Technical Abstract: Cats are among the most popular pets in the U.S., and the majority of these animals are kept indoors where litter boxes containing some type of absorbent litter material are needed. Dried distillers grains (DDGs) are one of the two major co-products (with carbon dioxide) of the corn ethanol industry, and these DDGs are primarily sold as animal feed. Our research group has been studying value-added uses for DDGs by extracting valuable phytochemicals from them with a variety of organic solvents. After extraction, it was found that these extracted DDGs exhibited enhanced water absorption capacity. The objective of this research was to determine if the extracted DDGs could be utilized as a biodegradable cat litter. DDGs from whole-kernel corn were extracted for 24 h with hexane using a Soxhlet apparatus to remove oil and other non-polar compounds, and dried for 24 h at 45oC to remove residual hexane. A suspension of 50 g of guar gum (commonly used as a clumping agent) in 500 g glycerol were added to 100 g samples of extracted DDGs at rates of 10, 25, 50 and 100 g, respectively. Clumping activity was determined by adding 5 g of each treatment into 60 mm x 15 mm plastic petri dishes, and allowing 5 ml of water to drip into each plate from a 100 ml burette placed 10 cm above the plates to simulate cat urination. These samples were placed in a drying oven set at 30oC for 24 h. The contents of each plate were emptied onto a 6-mesh sieve (large enough to allow all non-clumped extracted DDGs to fall through) and placed on an orbital shaker set at 250 rpm for 1 min. Clumping percentage was calculated as the weight of clumps retained on the top of the sieve divided by the total weight (5 g) multiplied by 100. Because copper compounds have been found to complex thiol compounds such as the specific cat urine odor compound, a guar/glycerol suspension was also prepared as before with the addition of 1 mg copper sulfate/ml glycerol, and a litter formulation was prepared as before containing 25 ml solution/100 g extracted DDGs. Headspace analysis vials containing litter formulations (1 g) with and without copper sulfate were incubated for 24 h with 0.2 ml of a solution of 3-mercapto-2-butanol before SPME-GC headspace analysis. Increasing levels of guar/glycerol significantly increased clumping percentage; however, the rate of 25 g solution/100 g extracted DDGs was determined as the most desirable formulation tested. Addition of copper sulfate substantially reduced the volatilization of 3-mercapto-2-butanol into the headspace of the vials. Our results indicate that extracted DDGs formulated with guar/glycerol/copper sulfate have excellent potential as commercial cat litter.