Phytate extraction from coproducts of the dry-grind corn ethanol process

Abstract

Distiller's dried grains with solubles (DDGS), the major coproduct of dry-grind ethanol production, are being increasingly used in the global market as animal feeds for both energy and protein supplement. DDGS contains high levels of phosphorus in the form of phytate, which cannot be digested by monogastric animals, such as poultry and swines, which in turn produce manure with high levels of phosphorus. Phytate is a highly-valued chemical and can be recovered from DDGS precursors in the downstream processing of dry-grind coproducts. This study was aimed at the utilization of the AG 1-X8 anion exchange resin to remove and purify phytates from thin stillage, and near 100% efficiency of adsorption and over 90% desorption from the resin beads was achieved. The end product showed a similar profile to the standard phytate, and could be precipitated and crystallized as calcium phytate. This process may potentially bring benefits to the parties involved, more revenue to corn ethanol facilities, improved digestibility of animal feeds, and minimized environmental impact, as less manure with a high content of phosphorus is applied to the soil.