Dry-grind processing of corn with endogenous liquefaction enzymes

An amylase corn has been developed that produces an α-amylase enzyme that is activated in the presence of water at elevated temperatures (>70°C). Amylase corn in the dry-grind process was evaluated and compared with the performance of exogenous amylases used in dry-grind processing. Amylase corn (1-10% by weight) was added to dent corn (of the same genetic background as the amylase corn) as treatments and resulting samples were evaluated for dry-grind ethanol fermentation using 150-g and 3-kg laboratory procedures. Ethanol concentrations during fermentation were compared with the control treatment (0% amylase corn addition or 100% dent corn) which was processed with a conventional amount of exogenous α-amylase enzymes used in the dry-grind corn process. The 1% amylase corn treatment (adding 1% amylase corn to dent corn) was sufficient to liquefy starch into dextrins. Following fermentation, ethanol concentrations from the 1% amylase corn treatment were similar to that of the control. Peak and breakdown viscosities of liquefied slurries for all amylase corn treatments were significantly higher than the control treatment. In contrast, final viscosities of liquefied slurries for all amylase corn treatments were lower than those of the control. Protein, fat, ash, and crude fiber contents of DDGS samples from the 3% amylase corn treatment and control were similar.