Source: UNIVERSITY OF ILLINOIS submitted to
MAIZE HYBRID VARIABILITY'S EFFECT ON ETHANOL AND COPRODUCTS YIELD
 
PROJECT DIRECTOR: Eckhoff, S. R.
 
PERFORMING ORGANIZATION
AGRI ENGINEERING
UNIVERSITY OF ILLINOIS
URBANA,IL 61801
 
NON TECHNICAL SUMMARY: Ethanol yields (grams ethanol/grams starch) have been found to differ between hybrids by as much as sixteen percent. Hybrid variability results in ethanol facility inefficiency and lost profitability. The purpose of the project is to identify the magnitude of variability in ethanol and coproducts yield as a result of hybrid differences.
 
OBJECTIVES: Overall objective is to evaluate the extent of the effect of hybrid variability on ethanol and coproducts yield. Various subobjectives will be explored but initially the study will focus on two objectives: 1. To develop small scale (5-50 gram) analytical procedures for rapidly and reproducibly evaluating the yield of ethanol from different corn samples for both wet milling and dry grind ethanol processes. 2. To evaluate the source of variability between hybrids.
 
APPROACH: Small scale procedures will be developed via modification of existing procedures with emphasis on reproducability and number of samples which can be handled per day. The source(s) of variability will be evaluated by comparing the variability observed in 12 hybrids selected to have different characteristics. The samples will be compared for starch liquifaction/saccarification rate, starch fermentation yield and dry grind fermentation yield.
 
CRIS NUMBER: 0190353 SUBFILE: CRIS
PROJECT NUMBER: ILLU-741-342 SPONSOR AGENCY: CSREES
PROJECT TYPE: HATCH PROJECT STATUS: TERMINATED MULTI-STATE PROJECT NUMBER: (N/A)
START DATE: Oct 1, 2001 TERMINATION DATE: Sep 30, 2006

GRANT PROGRAM: (N/A)
GRANT PROGRAM AREA: (N/A)

CLASSIFICATION
Knowledge Area (KA)Subject (S)Science (F)Objective (G)Percent
511151020202.150%
511729920202.150%

CLASSIFICATION HEADINGS
KA511 - New and Improved Non-Food Products and Processes
S7299 - Research equipment and methods, general/other
S1510 - Corn
F2020 - Engineering
G2.1 - Expand Domestic Market Opportunities


RESEARCH EFFORT CATEGORIES
BASIC (N/A)%
APPLIED 100%
DEVELOPMENTAL (N/A)%

KEYWORDS: ethanol; fuel; variability; maize; corn; fermentation; hybrids; saccharification; yields; non food commodities; agricultural engineering; process development; measurement; wet milling; dry milling; comparative analysis; corn starch

PROGRESS: Oct 1, 2001 TO Sep 30, 2006
The objective of this work was to show how variability due to genetic differences affect the utility of the end product. Due to an inability to secure funding to perform ethanol tests, we changed the target variability to the starch itself. In particular we wanted to look at the gel strength produced by a given pearl starch and the variability in same due to genetic differences. In order to study the thermal and rheological differences between hybrids we first had to determine the effect of laboratory batch steeping on rheological properties of starch. We found that we could buffer the system to 3.75 pH and not affect starch yield. A basic starch pudding was used as the food model for characterization of food pasting and gel strength properties. It was postulated that a 5 percent difference in final viscosity of the starch pasting properties would be the best predictor of a practical difference among food characteristics. Fifty-nine commercial corn hybrids grown in the same year at the same location were wet milled using a 100g laboratory procedure and the resulting starch was analyzed to determine the variability in pasting, gel and thermal properties. The final viscosities of the commercial sample set varied from 1697 cP to 2064 cP, from which five hybrids were selected to represent a viscosity range and tested for pasting properties and gel strength properties. The final viscosities were positively correlated to both starch gel strength characteristics of initial rupoture and gel strength at 7.5 mm depth with corerelation coefficients of 0.88 and 0.77 respectively. The selected hybrid were also tested to determine pudding pasting properties (RVA) and pudding gel strengths (texture analysis). The final viscosity of the starches was positively correlated to the initial rupture gel strength of the pudding with a correlation coefficient of 0.71. The initial rupture gel strength of the strongest gel was 10 percent stronger than the next strongest and 20 percent stronger than the weakest. By selecting the hybrid with the highest final viscosity you could potentially decrease the formulation by 10 to 20 percent to make a gel that has comparable gel strength to the other hybrids that were selected. Over 7.3 billion kg (290 million bushels) of corn per year is processed into starch (Economic Research Service, 2005), of which approximately half is for food use. At 15 percent MC and 70 percent starch db this would result in 2.2 billion kg of starch being used. At $0.264 per kg of starch (Economic Research Service, 2005) a 10 to 20 percent formula reduction would result in $58 to $117 million cost reduction by selecting specific hybrids for the food industry.

IMPACT: 2001-10-01 TO 2006-09-30 The study shows that there is a correlation between starch final viscosity and the strength of the gel produced from it. The correlation may be positive or negative depending upon the genetic background of the hybrids tested. What is important is not the direction of the correlation but rather the fact that so much potential variabilty exists. Processing selected hybrids would be one way to maximize pearl starch final viscosity and minimize cost to the manufacturer. The range of final viscosities exhibited by the hybrids was 4 times the minimim practical difference observed by industry. Over 7.3 billion kg (290 million bushels) of corn per year is processed into starch (Economic Research Service, 2005), of which approximately half is for food use. At 15 percent MC and 70 percent starch db this would result in 2.2 billion kg of starch being used. At $0.264 per kg of starch (Economic Research Service, 2005) a 10 to 20 percent formula reduction would result in $58 to $117 million cost reduction by selecting specific hybrids for the food industry. The expected result is that the food industry will put ever increasing pressure on starch suppliers to increase their viscosity of pearl starch and decrease variability in final viscosity.

PUBLICATION INFORMATION: 2001-10-01 TO 2006-09-30
Cabrales, L., Niu, Y.X., Buriak, P. and Eckhoff, S.R. 2006. Effect of laboratory batch steeping pH on starch yield and pasting properties of selected corn hybrids, Cereal Chemistry 83(1):22-24.

PROJECT CONTACT INFORMATION
NAME: Eckhoff, S. R.
PHONE: 217-244-4022
FAX: 217-244-0323