Effect of phytase corn addition on ethanol yield and distillers' dried grains with soluble profile in corn dry-grind process

Background and Objectives: Phytase as a feed additive improves the bioavailable phosphorus content of the poultry diet, thereby decreasing dependence on externally added phosphorus. The objective of this study was to determine the effect of adding phytase corn on ethanol yield and distillers' dried grains with soluble (DDGS) composition during a corn dry-grind process. Findings: Phytase corn at 2.5%, 5%, 7.5%, and 10% w/w of fermentable corn was added during the dry-grind process. Upon fermentation, the ethanol yield was observed to be in the range of 17.9%–18.9% v/v compared to control (17.7% v/v), representing an 1%–6.5% increase in ethanol yield. Relative to the corn that was introduced at the beginning of the fermentation, the DDGS obtained from the control corn or phytase corn addition all showed a threefold increase in oil, protein, and neutral detergent fiber content. However, the phytic acid content of the DDGS was reduced from 0.45% w/w (control) to 0.13% w/w (phytase treatments). Conclusion: Adding phytase corn in a dry-grind process improves the ethanol yield and reduces phytate-bound phosphorus content. Significance and Novelty: Phytase corn addition will improve the ethanol yield, DDGS nutritional quality in a corn dry-grind process, and reduce dependence on phosphorus supplementation.