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

► Dried distillers grains (DDGs) are a major co-product of the fuel ethanol industry. ► Solvent extraction of DDGs with hexane reduced the fermentation odor and increased water absorption by the extracted DDGs. ► The addition of guar gum as a clumping agent and glycerol as a dust retardant produced a cat litter formulation with desirable physical properties. ► Adding a small amount of copper sulfate to the cat litter formulation reduced the release of a volatile odor compound chemically similar to the compound naturally produced by the decomposition of cat urine. 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 a major co-product of the ethanol industry, and are primarily sold as animal feed. We have been studying value-added uses for DDGs by extracting valuable phytochemicals from them with a variety of organic solvents. The objective of this research was to determine if the extracted DDGs could be formulated as cat litter. Extracted DDGs absorbed significantly more water (termed hydration capacity) than unextracted DDGs, although sorting the extracted DDGs by particle size had no effect on hydration capacity. Through the addition of glycerol as a dust retardant and guar gum as a clumping agent, a formulation was obtained with desirable physical properties. The addition of copper sulfate to this formulation significantly reduced the release of a volatile odor compound that is chemically similar to the odor compound produced by the decomposition of cat urine. From these results it appears that extracted DDGs have potential as commercial cat litter.