Flow properties of DDGS with varying soluble and moisture contents using jenike shear testing

Distillers dried grains with solubles (DDGS) are an excellent source of energy, minerals, and bypass protein for ruminants and are used in monogastric rations as well. With the remarkable growth of the US fuel ethanol industry in the past decade, large quantities of distillers grains are now being produced. Flow of DDGS is often restricted by caking and bridging during its storage and transportation. In our previous works, the Carr powder tester was used to measure various flow properties of DDGS. The objective of this study was to measure the flow properties (cohesion, effective angle of friction, internal angle of friction, yield locus, flow function, major consolidating stress, and unconfined yield strength) of DDGS using the Jenike shear tester. This work investigated the influence of four levels of solubles (10, 15, 20, and 25% db) and five levels of moisture content (10, 15, 20, 25, and 30% db) on the resulting flow properties of DDGS. With an increase in soluble levels, the flow function curves of DDGS shift in an anticlockwise direction towards the shear stress (σc) axis. Depending on the soluble level, above certain moisture contents, the moisture actually began acting as a lubricant, easing the flow of the DDGS. Also, with higher solubles and moisture levels, the compressibility of DDGS was found to increase. Overall, the DDGS was classified as a cohesive material, and it is likely to produce cohesive arching problems. © 2008 Elsevier B.V. All rights reserved.