title: Phosphorus flow and characterization in dry-grind corn ethanol plants.
abstract: Both the high phosphorus (P) content and P bioavailability of the animal feed coproducts of the corn-ethanol industry could potentially contribute to increased manure and soil P levels and associated environmental issues (e.g., eutrophication). Therefore, a detailed modeling of total P mass flow to the coproducts (i.e., dry distillers grains with solubles, DDGS) was performed. Distribution of P between inorganic P and phytase-hydrolyzable P forms was quantified for selected coproducts (thin stillage, DDGS, modified DDGS [mDDGS]). The P mass balance indicated that although corn is the major P contributor to the coproducts (80.2%), a substantial portion (19.4%) comes from yeast addition. Of the two components constituting DDGS, wet distillers grains and condensed solubles, the latter contributes to only one-third of the mass but, importantly, yields 70.9% of P. The phytase enzyme used, , was very effective in hydrolyzing the nonorthophosphate P components of thin stillage, DDGS and mDDGS. Our results would help track P movement during various dry-grind processing steps and formulate strategies for phytase enzyme supplementation to various postfermentation coproducts from corn-ethanol plants.
authors.affiliation: Department of Biological Systems Engineering, University of Wisconsin, Madison, WI, USA.
authors.forename: A
authors.initials: A
authors.lastname: Alkan-Ozkaynak
authors.forename: K G
authors.initials: KG
authors.lastname: Karthikeyan
mesh_terms: D000818:Animals; D002417:Cattle; D000431:Ethanol / Q000138:chemical synthesis; D005260:Female; D008297:Male; D010758:Phosphorus / Q000737:chemistry*; D017553:Phosphorus Compounds / Q000032:analysis; D010833:Phytic Acid / Q000032:analysis; D003313:Zea mays / Q000737:chemistry*
chemical_list: D017553:Phosphorus Compounds; D010758:Phosphorus; D000431:Ethanol; D010833:Phytic Acid