Starch Fermentation Characteristics for Different Proportions of Amylose and Amylopectin

The amylose: amylopectin ratio in corn starch is known to affect its chemical characteristics. Yellow dent corn contains 20 to 30% amylose and 70 to 80% amylopectin. Effects of amylose: amylopectin ratios on corn starch fermentation characteristic were investigated. Commercially available starches Hylon VII (70% amylose and 30% amylopectin) and Amioca (100% amylopectin) were mixed in varying proportions. Fermentations were performed using granular starch hydrolyzing enzyme and conventional enzymes. Differences were found in ethanol yield among starches containing different ratios of amylose and amylopectin and among enzymes used. Ethanol concentrations varied from 2.2 to 9.1 (% v/v) for fermentation with granular starch hydrolyzing enzyme and from 6.7 to 9.3 (% v/v) for conventional enzymes.