The effect of condensed distillers solubles on the physical and chemical properties of maize distillers dried grains with solubles (DDGS) using bench scale experiments

This study was undertaken to understand the effect of variable quantities of condensed distillers solubles (CDS) mixed with wet distillers grains (WDG) from maize on the physical and chemical characteristics of distillers dried grains with solubles (DDGS) using a bench-scale experiment. DDGS produced with 0, 10 and 20% CDS by percentage mass showed that particle size, particle size distribution, and particle density increased with CDS levels from 0 to 20%. DDGS with varying CDS levels had significantly different amounts of crude protein, crude fat, ash, total reducing sugars and amino acids. The chemical composition of DDGS in this study and a plant-scale study by Kingsly et al. (2010) were comparable, but not their physical characteristics. Therefore, caution should be taken when preparing DDGS samples for use in studying granular properties using bench-scale experiments which have been used by others in previous studies. An empirical model was developed to predict the chemical composition of DDGS based on the chemical composition of its two wet streams.

► Physical/chemical characteristics of DDGS from bench/plant-scale studies compared. ► Limitation of using bench-scale studies was in the physical properties. ► Chemical properties of DDGS were comparable across both bench and plant scales. ► DDGS add-back (recycle) important during DDGS drying at the plant scale. ► Model developed to predict chemical property of DDGS based on feedstock streams.