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Addition of cellulolytic enzymes and phytase for improving ethanol fermentation performance and oil recovery in corn dry grind process
- Luangthongkam, P., Fang, L., Noomhorm, A., Lamsal, B.
- Industrial crops and products 2015 v.77 pp. 803-808
- corn, enzymatic treatment, ethanol, ethanol fermentation, ethanol production, liquefaction, oils, pH, phytases, polysaccharides, proteinases, saccharification, xylanases
- Application of hydrolytic and other enzymes for improving fermentation performance and oil recovery in corn dry-grind process was optimized. Non-starch polysaccharide enzymes (BluZy-P XL; predominantly xylanase activity) were added at stages prior to fermentation at optimum conditions of 50°C and pH 5.2 and compared with conventional fermentation (30°C, pH 4.0). Enzyme applications resulted in faster ethanol production rates with a slight increase in yield compared to control. The thin stillage yield increased by 0.7–5% w/w wet basis with corresponding increase in solids content with enzyme treatment after liquefaction. The oil partitioned in thin stillage was at 67.7% dry basis after treatment with hydrolytic enzymes during fermentation. Further addition of protease and phytase during simultaneous saccharification and fermentation increased thin stillage oil partitioning to 77.8%. It also influenced other fermentation parameters, e.g., ethanol production rate increased to 1.16g/g dry corn per hour, and thin stillage wet solids increased by 2% w/w. This study indicated that treatments with non-starch hydrolytic enzymes have potential to improve the performance of corn dry-grind process including oil partitioning into thin stillage. The novelty of this research is the addition of protease and phytase enzymes during simultaneous saccharification and fermentation of corn dry-grind process, which further improved ethanol yields and oil partitioning into thin stillage.