Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2004
Publication Date: 5/30/2004
Citation: Naidu, K., Rausch, K.D., Johnston, D., Tumbleson, M.E., Singh, V. A two-liter dry grind laboratory procedure to measure sugar profile and ethanol yields. Proceedings of the Corn Utilization & Technology Conference, Indianapolis, IN., June 7-9, 2004. Poster Presentation CD Rom.
Technical Abstract: Currently, over 60% of ethanol produced in the US is by the dry-grind ethanol process. The first step in preparing corn mash is grinding. Fineness of grind influences the amount of sugars formed and the viscosity of thin stillage. However, there is lack of information on the effect of corn flour particle size on ethanol yield and the amount of soluble solids present in thin stillage. To determine the effect of corn flour particle size on sugar profile and ethanol yield, a two-liter laboratory dry grind procedure was developed. Whole corn kernels were ground in a cross-beater mill to 500 g of ground material followed by liquefaction, saccharification and fermentation. The procedure was developed using a yellow dent corn hybrid and was optimized for the grinding, liquefaction, saccharification and fermentation parameters. Two-liter mash is subjected to four different variations in the primary process parameters: concentrations of alpha amylase (0.24-2.4 mg/g of corn) and glucoamylase (0.575-3.45 mg/g of corn); temperatures of liquefaction (80 - 110 ºC) and saccharification (50 - 65 ºC); dry solids concentration in mash (20 - 35 %) and yeast inoculum added (5 - 60 ml). Sugar profiles and ethanol yields were measured with HPLC using Aminex column and a refractive index detector. A full factorial randomized complete block design was used to optimize the process parameters. The optimized procedure is reproducible with a low standard deviation.