Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: ENZYME-BASED TECHNOLOGIES FOR MILLING GRAINS AND PRODUCING BIOBASED PRODUCTS AND FUELS
2006 Annual Report


1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
Corn wet milling is the primary route to produce starch and glucose, major feedstocks for fermentation-, chemically- and thermochemically-derived biobased products, fuel ethanol, and numerous food ingredients. A major problem for the wet milling industry is that sulfite, a regulated hazardous chemical required for the process, adds considerable cost, creates occupational safety and health concerns, and prevents the major protein coproducts from being consumed as human food. Consumers, biobased product manufacturers, and the entire wet milling industry would benefit from a sulfite-free process that generates high yields of starch and high quality protein and oil coproducts. The other major process by which corn is processed today is by the dry grind process. Dry grind corn processing (not Dry Milling) is currently used exclusively for ethanol production. While dry grind processing is very efficient in producing ethanol, it suffers from the limitation of producing only one coproduct, DDGS, a relatively low value animal feed with limited sales markets. Developing new technologies and processes that help expand the number of coproducts, their value and/or their available markets, could prove vital to the long-term success and survival of the corn processing industry. Developing new, alternative, cost-effective and environmentally sustainable methods for the processing of corn into ethanol, starch, oil, protein and other coproducts, will provide additional income for rural growers and processors and make the U.S. more energy independent.

The increased use of ethanol as an oxygenate in gasoline is creating a significant demand for additional production capabilities. Many new fuel ethanol plants are being constructed to meet this demand and many existing facilities are expanding their production capacity. The dry grind process currently used for ethanol production, while efficient, suffers from a number of limitations. The most significant limitation is that it produces only one co-product (other than ethanol) and this is only used as low value animal feed with limited markets. The wet milling process currently used produces a number of co-products in addition to ethanol; however, they are limited as well in their markets due in part to the chemical processing aids used in steeping. Developing new technologies and processes that help to expand the number of co-products or their available markets could prove vital to the long-term success and survival of the industry.

The project responds directly to three problem areas of the NP306 action plan’s "Component 2, New Processes, New Uses, and Value-Added Biobased Products". Specifically it responds to Problem Area 2a, "New Product Technology". Specifically it responds to "Improve understanding of the relationship between composition, molecular structure, and physical state and end-use functionality of these compounds and components" and to "Use new knowledge of product properties and component interactions to develop functional intermediates or products" (New functional starch derivatives). It responds to Problem Area 2b, "New Uses for Agricultural Byproducts" because we will "Convert low value agricultural residues into higher value products" (corn gluten and DDGS into value added feeds and foods). Finally it responds to Problem Area 2c, "New and Improved Processes and Feedstocks", since this project plans to "Develop improved and new techniques and technologies to convert agricultural products into value-added biobased products" and to "Improve/develop processes and technologies that are environmentally benign" through our use of enzymatic milling and non-hazardous solvent carbohydrate modification processes. The project also responds directly to the "Ethanol" problem area of NP 307 Action Plan's Component I, "Ethanol" specifically by developing new "Process Efficiencies" and participating in "Coproduct Development".


2.List by year the currently approved milestones (indicators of research progress)
FY 2005 Begin Screening of new enzymes for use in enzymatic milling

Begin testing of potential sources for protease activity

Begin testing of sonication on conventional corn wet milling.

Begin evaluation of lactic acid on E-Milling co-product yields.

Begin evaluation of co-product composition from E-Milling using lactic acid addition.

Develop and validate process and cost models for a conventional wet-milling facility.

Begin development of fiber removal and fermentation protocols.

Begin evaluation of yields and compositions of products and co-products from the fiber removal and fermentation protocols.

Conduct a sensitivity analysis for the co-production of Astaxanthin using modified dry grind processes.

Begin development of cost sensitivity analysis for mixed or multi-step fermentations for co-production of multiple products.

Begin production of Corn Fiber Gum from milling fractions.

Begin linkage and compositional analysis of polysaccharide starting materials for modifying carbohydrate rich fractions from the enzymatic milling processes.

FY 2006 Begin determination of milling yields for new enzymes found to be potentially useful in the enzymatic milling processes.

Begin evaluation of co-product composition from new commercial enzymes.

Finish testing of potential sources for protease activity.

Begin production and isolation of enzymes for milling tests.

Finish testing of sonication on conventional corn wet milling.

Begin testing of sonication on enzymatic corn wet milling.

Finish evaluation of lactic acid on E-Milling co-product yields.

Finish evaluation of co-product composition from E-Milling using lactic acid addition.

Characterize proteins in co-products from E-Milling using lactic acid addition

Develop and validate process and cost models for an enzymatic wet-milling facility.

Continue development of fiber removal and fermentation protocols.

Continue evaluation of yields and compositions of products and co-products from the fiber removal and fermentation protocols.

Begin development of alternative heating protocol for mashing to minimize peak viscosity using the RVA.

Begin studies on the production of Astaxanthin and ethanol in a defined media.

Begin analysis of co-products from co-production of Astaxanthin and ethanol.

Finish development of cost sensitivity analysis for mixed or multi-step fermentations for co-production of multiple products.

Continue production of Corn Fiber Gum from milling fractions.

Begin studies treating Corn Fiber Gum with L-arabinofuranosidases on a small scale to produce polysaccharides having new functional properties.

Isolate Corn Fiber Gum from commercial wet milling fiber for treatment and characterization studies.

Continue linkage and compositional analysis of polysaccharide starting materials for modifying carbohydrate rich fractions from the enzymatic milling processes.

Begin development of enzymatic modification strategies for modifying the carbohydrate rich fractions from the enzymatic milling processes.

FY 2007 Finish Screening of new enzymes for use in enzymatic milling

Finish testing of sonication on enzymatic corn wet milling.

Begin testing of new chemical treatments and corresponding co-product composition.

Compare conventional and E-Milling models and what if studies

Finish development of fiber removal and fermentation protocols.

Finish evaluation of yields and compositions of products and co-products from the fiber removal and fermentation protocols.

Finish development of alternative heating protocol for mashing to minimize peak viscosity using the RVA.

Begin evaluation of alternative enzyme treatments during mashing using modified protocols using the RVA.

Begin evaluation of the effects of the modified mashing protocols on co-products.

Finish studies on the production of Astaxanthin and ethanol in a defined media.

Continue analysis of co-products from co-production of Astaxanthin and ethanol.

Begin development and validation of modified dry grind process and cost models.

Finish production of Corn Fiber Gum from milling fractions.

Finish studies treating Corn Fiber Gum with L-arabinofuranosidases on a small scale to produce polysaccharides having new functional properties.

Treat the isolated Corn Fiber Gum from commercial wet milling fiber with xylanases and isolate modified material.

Finish development of enzymatic modification strategies for modifying the carbohydrate rich fractions from the enzymatic milling processes.

Begin production of enzyme modified carbohydrate polymers.

FY2008 Finish determining milling yields for enzyme found to be potentially useful.

Continue evaluation of coproduct composition from commercial enzymes.

Finish production and isolation of enzymes for milling tests.

Begin evaluation of coproduct composition from non-commercial enzymes.

Continue testing new chemical treatments and coproducts.

Finish evaluating alternative enzyme treatments during mashing using modified protocols using RVA.

Continue evaluating the effects of the modified protocols on coproducts.

Continue testing protocols on larger laboratory scale.

Begin production of Astaxanthin and ethanol in modified corn mash.

Finish coproduct analysis.

Begin feeding trials with collaborators.

Finish development and validation of modified dry grind models.

Begin development of cost and process model for mixed product production with modified dry grind production as foundation.

Begin production and characterization of modified coproducts.

Finish characterization of xylanase treated products.

Finish production of enzyme modified carbohydrate polymers.

Begin characterization of modified polymers.

FY 2009 Finish evaluation of coproduct composition from commercial enzymes.

Finish evaluation of coproduct composition from non-commercial enzymes.

Finish test new chemical treatments and coproducts.

Finish evaluating the effects of the modified protocols on coproducts.

Finish test protocols on larger laboratory scale.

Finish production of Astaxanthin and ethanol in modified corn mash.

Finish coproduct analysis.

Finish feeding trials with collaborators.

Finish development of cost and process model for mixed product production with modified dry grind production as foundation.

Finish production and characterization of modified coproducts.

Finish characterization of modified polymers.


4a.List the single most significant research accomplishment during FY 2006.
Plant Trial of the Enzymatic Wet Milling Process This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." A commercial plant trial of the Enzymatic Wet Milling process was conducted at a 200 metric ton per day facility in Malaysia by researchers from the Crop Conversion Science and Engineering research unit in cooperation with researchers from the University of Illinois under a SCS, 1935-4100-070-05S, Enzymatic Milling Commercial Plant Trial. Previous trials had been done in small batch operations and could not be used to demonstrate the effectiveness using a continuous system. Modifications were made and a series of conventional runs were conducted prior to switching the facility to run using the enzymatic process. Five separate enzymatic runs were conducted and yields and coproducts collected for analysis from the conventional and enzymatic runs. Starch yields were found to be significantly higher using the enzymatic process when compared to the conventional starch yields and coproducts were not found to be significantly different in composition. This successful demonstration will allow other wet milling facilities to better evaluate the enzymatic wet milling technology and determine the economic advantages relative to the current process. The patented process is currently being licensed by a major enzyme manufacturer.


4b.List other significant research accomplishment(s), if any.
Development of an Enzymatic Wet Milling Process Model This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products” Problem Area 2c, "New and Improved Processes and Feedstocks." Researchers working on modified corn wet-milling research at ERRC and elsewhere had no process and cost model with which to understand and predict the operations of the proposed enzymatic wet milling process and to understand how proposed changes in the existing technology might be affect by these modification. During fiscal year 2006 unit researchers from the Crop Conversion Science and Engineering research unit, in conjunction with SUPER Group process and cost engineers, developed a SuperPro Designer process and cost model, using data gleaned from laboratory data, public information and industry contacts. This updated model will be of exceptional value to CCS&E's Enzymatic Milling Program which aims to use enzymes to eliminate toxic sulfites from wet milling and will also be of major value to all researchers over the world doing work in this area. This model has been shared with several industry partners, and will be made publicly available in the near future in the same manner as our other process models.

Identification of Phenolic Acids, Lipids and Proteins from Corn Fiber Gum This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2b, "Use new knowledge of product properties and component interactions to develop functional intermediates or products." The functional groups-phenolic acids, lipids and proteins were identified in corn fiber gum (CFG) and then isolated and chemically characterized. The results showed that these functional groups are present in CFG in sufficient quantity that they may provide some limited nutraceutical value. They may also be potentially applied as a prebiotic and potential source of soluble dietary fiber to the foods and beverage to which they will be added. This information will be useful to the food and beverage industry in general and to other researchers studying structure function relationships.

Molecular Characterization of Corn Fiber Gum This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2b, "Use new knowledge of product properties and component interactions to develop functional intermediates or products." Molecular characterization of CFGs (fractions 1 and.
2)isolated from different corn fiber sources were done and correlated to their emulsifying properties. The results indicated that CFG fraction with higher molecular weight is a more effective emulsifier than the corresponding lower molecular weight fraction isolated from the same fiber source for oil-in-water beverage emulsion system. This information will be useful to the food and beverage industry in general by providing an alternative to imported high cost food gums. This information will also be useful to manufactures of products requiring stabilization of oil water emulsions such as in the manufacturing of paint and to researchers studying emulsification properties of polysaccharides.


4c.List significant activities that support special target populations.
None.


4d.Progress report.
1935-41000-070-01S: This report serves to document research conducted under a Specific Cooperative Agreement between ARS and the University of Illinois at Urbana-Champaign. This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." This accomplishment is also aligned with National Program 307 Component 1, "Ethanol." This research project was developed with Univ. of Illinois to pursue the common goal of improving the dry grind ethanol process through the use of "Modified Corn Milling Technologies". A Ph.D. student, funded under this agreement, began working in the Department of Agricultural Engineering at the University of Illinois in the fall 2003 Semester. This student will be doing his doctoral studies on bioprocess control and process simulation and will spend several months at the Eastern Regional Research Center.

Previously a modified dry grind corn process (E-mill process) to recover germ, pericarp fiber and endosperm fiber prior to fermentation was developed. Recovery of coproducts in E-mill process was improved by use of raw starch hydrolyzing enzymes.

Projects completed this year: 1. Comparison of raw starch hydrolyzing enzyme with conventional liquefaction and saccharification enzymes in dry grind corn processing. 2. Comparison of fermentation profiles for wet and dry fractionation technologies prior to dry grind corn process. 3. Addition of germ soakwater and micronutrients to improve the fermentation profiles in dry fractionation prior to dry grind corn process. 4. Addition of lipid supplements to improve the fermentation profiles in dry fractionation prior to dry grind corn process. 5. Effect of ground corn particle size on ethanol yield and thin stillage soluble solids.

1935-41000-070-02T: This report serves to document research conducted under a Specific Cooperative Agreement between ARS and the University of Illinois at Urbana-Champaign. This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." This cooperative agreement is the result of a successful grant proposal submitted by ERRC and University of Illinois to the USDA-CSREES Initiative for Future Agriculture and Food Systems. The work being done under this agreement is a joint effort to lower the overall processing costs for wet milling and improve the economics of fuel ethanol through the development of enzymatic processing technology.

1935-41000-070-03S: This report serves to document research conducted under a Specific Cooperative Agreement between ARS and the University of Illinois at Urbana-Champaign. This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." This cooperative agreement is the result of a successful grant proposal submitted by ERRC and University of Illinois to the USDA-CSREES Initiative for Future Agriculture and Food Systems. The work being done under this agreement is a joint effort to lower the overall processing costs for wet milling and improve the economics of fuel ethanol through the development of enzymatic processing technology.

1935-41000-070-04M: This report serves to document A Memorandum of Understanding, developed between the Eastern Regional Research Center, the Corn Refiners Association and the University of Illinois. The agreement was designed to formally establish and strengthen the research relationship between the parties, which has until now been operating under an informal agreement. The parties all share common research interest involving corn processing and this agreement will nourish this interest and improve collaboration benefiting everyone involved.

A number of contacts with member companies of the Corn Refiners Association have taken place during the fiscal 2006 reporting period. Interaction continues to address aspects of process modeling and coproduct composition. The process model developed under the parent project (1935-41000-070-00D) was shared with members of the Corn Refiners Association. Results from the Enzymatic Wet milling plant trial that was conducted in Malaysia during August 2005 were presented at the Corn Utilization Conference in Dallas, TX with many representatives of CRA technical committee in attendance.

1935-41000-070-05S: This report serves to document research conducted under a SCA between ARS and the University of Illinois at Urbana-Champaign. This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." This research project was developed with the University of Illinois at Urbana-Champaign to pursue the common goal of conducting a commercial plant scale trial of the jointly developed enzymatic wet milling process.

A commercial plant trial of the Enzymatic Wet Milling process was conducted at a 200 metric ton per day facility in Malaysia during fiscal year 2006 by researchers from the Crop Conversion Science and Engineering research unit in cooperation with researchers from the University of Illinois under a SCS, 1935-4100-070-05S, Enzymatic Milling Commercial Plant Trial. Previous trials had been done in small batch operations and could not be used to demonstrate the effectiveness using a continuous system. Modifications were made and a series of conventional runs were conducted prior to switching the facility to run using the enzymatic process. Five separate enzymatic runs were conducted and yields and coproducts collected for analysis from the conventional and enzymatic runs. Starch yields were found to be significantly higher using the enzymatic process when compared to the conventional starch yields and coproducts were not found to be significantly different in composition. This successful demonstration will allow other wet milling facilities to better evaluate the enzymatic wet milling technology and determine the economic advantages relative to the current process. The patented process is currently being licensed by a major enzyme manufacturer.


5.Describe the major accomplishments to date and their predicted or actual impact.
Dry Grind Ethanol Process and Cost Model This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." This accomplishment is also aligned with National Program 307 Component 1, "Ethanol." The development of a process engineering and cost model for a 40 Million gallon per year Corn Dry-Grind Ethanol facility was successfully developed by researchers during fiscal year 2005 from the Crop Conversion Science and Engineering research unit. The model was developed using a user friendly software program called SuperPro Designer®. Previous models were only available to those who had access to expensive, highly complex process engineering software applications. This model has been made freely available and can be utilized by ethanol producers, academics and researchers for studying processing and economic aspects of fuel ethanol production. The model has been requested by over one hundred researchers in industry, academia as well as other US government agencies. This model will serve as the base-case for comparison to future proposed process modifications.

Pilot Testing of a Modified Dry Grind Corn Process This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." This accomplishment is also aligned with National Program 307 Component 1, "Ethanol." The increase in the production of fuel ethanol from corn by the dry grind process has increased dramatically over the past few years. Increased production of ethanol has also increased the interest of new processing strategies to improve efficiency and overall process economics. Researchers in the Crop Conversion Science and Engineering research unit have developed and patented an enzyme-based process that can be used to recover germ (extracted for oil) and pericarp fiber prior to entering fermentation. This process was developed on a lab scale and was tested on a 4 bushel (200 kg) scale at the ERRC grain processing pilot plant. Data derived from this pilot study can be used to further scale the process for potential use on a commercial production scale. The new coproducts produced will be used in feeding studies to determine their acceptability in new markets. This information will be of value to ethanol processors and researchers and may lead to economic improvements in ethanol production and the production of value added coproducts.

Updated Corn Wet Milling Process Model This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." Researchers working on advanced corn wet-milling research at ERRC and elsewhere had no validated and publicly available wet mill process and cost model with which to understand the operations of current wet mills and to understand how proposed changes in technology might affect existing process. Unit researchers from the Crop Conversion Science and Engineering research unit, in conjunction with SUPER Group process and cost engineers, developed an ASPEN+ process and cost model, using data gleaned from public information and industry contacts. This model was made available last year and had been validated by most of the major wet millers in the US, including ADM, Tate and Lyle, Cargill, and Penford. This model was updated and transferred to a software program SuperPro Designer® that is much less expensive, more user friendly and readily available so it can be used by a broader range of people. This updated model will be of exceptional value to CCS&E's Enzymatic Milling Program which aims to use enzymes to remove toxic sulfites from wet milling and will also be of major value to all researchers over the world doing work in this area.

Corn Germ Compositional and Economic Comparison This accomplishment aligns with National Program 306 Component 2, New Processes, New Uses, and Value-Added Biobased Products" Problem Area 2c, "New and Improved Processes and Feedstocks." Researchers working to improve the corn processing at ERRC have produced, analyzed, and compared corn germ derived from conventional and modified process technologies. Currently about 90% of the corn germ that is extracted for corn oil is derived from the wet milling process. Process modification or alternative process methods could be used for germ production, but the composition and value of germ from these processes was not readily available. By producing and analyzing germ from conventional and modified processes the researchers were able to develop a formula to estimate the economic value for germ from each process. This work will be useful for industry and other researchers studying the current milling process and for evaluation of new germ recovery technologies. This work could be used in optimization of production processes leading to decreased operation costs and increased profitability. This work was considered so useful, that the American Oil Chemist Society awarded its authors with a "Best paper award" in the Protein and Coproducts Division in 2006.


6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Researchers from the CRIS presented research at an international meeting in Portugal and at a meeting in Dallas discussing enzyme based strategies for improving coproduct isolation and fuel ethanol production.

Researchers from the CRIS met with scientists from one of the world's largest enzyme companies, to transfer technology on enzyme based corn processing and to discuss new enzyme strategies for recovering value added coproducts during corn processing.

The process and cost models developed for dry grind processing and corn wet milling were distributed upon request to people from academia, government and industry.


7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
1. Murthy, G.S., Singh, V., Rausch, K.D., Johnston, D.B. and Tumbleson, M.E. 2006. Effect of B vitamin and lipid supplementation to improve fermentation characteristics of the modified dry grind process. Paper No. 066067 American Society of Agricultural and Biological Engineers, St. Joseph, MI.

2. Murthy, G.S., Singh, V., Rausch, K.D., Johnston, D.B. and Tumbleson, M.E. 2006. Mathematical modeling of enzymatic hydrolysis of starch: application to fuel ethanol production. Paper No. 066229. American Society of Agricultural and Biological Engineers, St. Joseph, MI.

3. Madhav P. Yadav, Robert A. Moreau and Kevin B. Hicks, Phenolic acids, lipids and proteins in corn fiber gum, Corn Utilization and Technology Conference, Dallas, TX, June 5-7, 2006, Poster # 31 (Presentation, Log # 0000193071)

4. Johnston, D. Enzymatic Processing of Corn for Food, Feed and Fuel. Presentation at the AACC meeting, San Francisco, CA, Sept 17-20, 2006. (Presentation, Log # 195015)

5. Johnston, D. and Singh, V. Enzymatic Corn Wet Milling: Results from a Commercial Plant Trial. Corn Utilization and Technology Conference, Dallas, TX, June 5-7, 2006, (Presentation, Log # 193323)


Review Publications
Yadav, M.P., Johnston, D., Hicks, K.B., Nothnagel, E.A. 2006. The role of lipid and protein components in the emulsification properties of gum arabic and corn fiber gum. Foods & Food Ingredients Journal of Japan. V.211, No. 3.p.243-254.

Murthy, G., Singh, V., Johnston, D., Rausch, K.D., Tumbleson, M.E. 2006. Improvement in fermentation characteristics of degermed ground corn by lipid supplementation. 2006. Journal of Industrial Microbiology Biotechnology 33:655-660.

Last Modified: 8/21/2014
Footer Content Back to Top of Page