Particle heterogeneity of corn distillers dried grains with solubles (DDGS)

In this study the physical, morphological and chemical characteristics of distillers dried grains with solubles (DDGS) produced by mixing three levels of condensed distillers soluble (CDS) (0%, 3.69% and 7.39% volumetric basis, v.b.) with wet distillers grains and drying were characterized. Decreasing the CDS level from 7.39% to 0% v.b. resulted in a reduction of 13.9% in geometric mean particle size and 8.8% in bulk density while the compressibility of the material increased by 3%. As the CDS level increased, pore volume, particle porosity and effective bulk porosity decreased. Crude fat, crude protein, crude fiber and ash content showed distinct patterns for all three samples studied and suggest that US sieve no. 16 (1190 μm) may be an inflection point for the chemical characteristics of DDGS granules within a bulk. The observed heterogeneity could cause sampling errors and particle segregation, and as a consequence nutrient and bulk density variability.