Upcycling Renewable Ethanol Grain Fermentation Co‑Products in a Circular Bioeconomy: Technological Pathways to High‑Value, Low‑Impact Protein Production

Peter E.V. Williams; Emily J. Burton

doi:10.55845/joce-2026-41283

Authors

Peter E.V. Williams Fluid Quip Technologies, 6105 Rockwell Drive NE, Cedar Rapids, Iowa, USA Author
Emily J. Burton Nottingham Trent University, Brackenhurst Campus Location: Brackenhurst Lane, Southwell, Nottinghamshire, NG25 0QF, United Kingdom Author

DOI:

https://doi.org/10.55845/joce-2026-41283

Keywords:

Biofuels, Renewables, Protein, Protein-gap, Distillers Dried Grains and Solubles, Corn Fermented Protein, Biofuels-food Competition

Abstract

In 2024 European renewable ethanol producers produced 6.9 million tons of food and feed co-products and 6.8 billion litres of renewable ethanol biofuel. Liquid renewable fuels such as bioethanol make an average greenhouse gas saving of 79% compared to fossil fuels. Recent advances in mechanical up-cycling of these traditional feed coproducts produces a new high-quality protein, Corn Fermented Protein (CFP) (Crude Protein content>50%) that can replace imported GM plant proteins currently used in feed formulations for aquaculture, pet food and livestock feeds. The fuel ethanol fermentation technology is undervalued because in fermentation protein is created. Fermentation to produce ethanol relies on the activity of yeast that is grown using approximately 8-10% of the feedstock grain starch, plus either gaseous ammonia or urea as a nitrogen source. Yeast cells are approximately 40% protein and form part of the feed co-products produced in the bioethanol process. Novel fractionation technologies up-cycle the traditional protein co-product (distillers dried grains and solubles; DDGS; a median protein approx. 30% crude protein) to produce a new Super Protein product (CFP) (>50-60% crude protein concentration) in so doing recovering a major proportion of the spent yeast that contains important immuno stimulants. CFP has been extensively tested, as a replacement of soybean meal in feed for poultry, swine, ruminants, aquaculture and companion animals. The new protein is devoid of any anti nutritional factors and highly suited for formulation in feed for aquaculture and companion animals. In addition, the spent yeast cell wall beta-glucans, act as immuno stimulants proven to reduce mortality when used in aquaculture feed. When used in feed for dogs CFP increases palatability. CFP has a significantly lower carbon index compared with many traditional feed proteins. Using CFP in feed formulation lowers the carbon index of feed products. Upcycling distillers dried grains and solubles into CFP helps lower Europe's protein deficit, reduces feed carbon footprint, and creates additional valuable markets for ethanol co-products.

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