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United States Department of Agriculture

Agricultural Research Service

Research Project: ENZYME-BASED TECHNOLOGIES FOR MILLING GRAINS AND PRODUCING BIOBASED PRODUCTS AND FUELS
2005 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? What 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 the milestones (indicators of progress) from your Project Plan.
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.

Finish 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.What was the single most significant accomplishment this past year?
Dry Grind Ethanol Process and Cost Model 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 from the Crop Conversion Science and Engineering research unit. The model was developed using a user friendly software program. 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 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.


4b.List other significant accomplishments, if any.
Corn Fiber Gum Emulsification Studies The emulsification properties of corn fiber gum (CFG) isolated from the low-valued corn milling byproduct, corn fiber, has been studied for its potential use in food and industrial applications. Gums that are used for emulsifying agents are typically expensive, imported and of variable quality. The properties of the domestically produced CFG were studied and indicate that it can potentially be used as a replacement for certain applications of the imported acacia gums. A manuscript documenting the findings of this study has been submitted for publication and the results were presented at an international conference.

Pilot Testing of a Modified Dry Grind Corn Process 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.

Updated Corn Wet Milling Process Model 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 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 that is 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.

Amino Acid Profiling During Corn to Ethanol Processing Researchers working to improve the corn to ethanol process at ERRC have been studying the uptake and release of amino acids during ethanol production in order to improve the efficiency and final coproduct nutrient contents. Fermentation rates and coproduct qualities are directly related to the initial and final nutrient contents and can be adversely affected by removal of components during modified processing or other processing modifications. This research has shown that the addition of enzymes and inorganic nitrogen can alter the amino acids available to the yeast and can increase the ethanol production rate. This information could be used by industry, enzyme companies, ethanol producers and researchers for further improving amino acid release.

Corn Germ Compositional and Economic Comparison 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.


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


4d.Progress report.
1935-41000-070-01S-This report serves to document research conducted under a SCA between ARS and the University of Illinois at Urbana-Champaign. Additional details of research can be found in the report of the parent CRIS, 1935-41000-070-00D, Enzyme-based Technologies for Milling Grains and Producing Biobased Products and Fuels. This research project was developed by the 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.

A process to fractionate corn kernel to recover germ, pericarp fiber and endosperm fiber prior to fermentation was developed for dry grind corn process. The new process, called the enzymatic dry grind process, increases production capacity, improves fermentation efficiency and recovers valuable coproducts. Recently a manuscript was published in Cereal Chemistry and a US patent was granted related to this process.

Currently we are evaluating new enzymes with high native starch degrading activities to further improve the enzymatic dry grind process. A manuscript has recently been accepted in Cereal Chemistry for publication related to this work. Another manuscript comparing the characteristics of new enzyme with conventional dry grind enzymes is being prepared for submission to Journal.

Scale of up of the enzymatic dry grind process is currently being pursued at the University of Illinois and at the Eastern Regional Research Center, ARS, USDA. Scale up of another process previously developed for corn wet milling is being pursued in Southeast Asia.

Comparison of wet and dry degerm and defiber technologies at the beginning of dry grind ethanol are being evaluated for dry grind ethanol fermentation profiles. Addition of germ soakwater and micronutrients to improve the fermentation profiles is also being evaluated.

1935-41000-070-02T-This report serves to document research conducted under a SCA between ARS and the University of Illinois at Urbana-Champaign. Additional details of research can be found in the report of the parent CRIS, 1935-41000-070-00D, Enzyme-based Technologies for Milling Grains and Producing Biobased Products and Fuels. During this reporting period, research was also conducted under subordinate CRIS projects, 1935-41000-070-03S (SCA with U of I) and 1935-41000-070-02T (ARS In house project), Enzymatic Corn Wet milling process. This work was conducted under a specific cooperative agreement between ARS and the University of Illinois, which was initiated on 09/25/00 and will terminate on 09/24/05. 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.

Under this project, a small plant trial (200 Metric Tons per day) of the enzymatic wet milling process (E-Milling) will be done. This process was developed and patented in part under this agreement. The plant trial is scheduled to take place in Malaysia during August 2005.

1935-41000-070-03S-This report serves to document research conducted under a SCA between ARS and the University of Illinois at Urbana-Champaign. Additional details of research can be found in the report of the parent CRIS, 1935-41000-070-00D, Enzyme-based Technologies for Milling Grains and Producing Biobased Products and Fuels. During this reporting period, research was also conducted under subordinate CRIS projects, 1935-41000-070-03S (SCA with U of I) and 1935-41000-070-02T (ARS In house project), Enzymatic Corn Wet milling process. This work was conducted under a specific cooperative agreement between ARS and the University of Illinois, which was initiated on 09/25/00 and will terminate on 09/24/05. This cooperative agreement is the result of a successful grant proposal submitted by ERRC and the 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.

Under this project, a small plant trial (200 Metric Tons per day) of the enzymatic wet milling process (E-Milling) will be done. This process was developed and patented in part under this agreement. The plant trial is scheduled to take place in Malaysia during August 2005.

1934-41000-070-04M-This report serves to document research conducted under a MOU between ARS, the Corn Refiners Association and the University of Illinois at Urbana-Champaign. Additional details of research can be found in the report of the parent CRIS, 1935-41000-070-00D, Enzyme-based Technologies for Milling Grains and Producing Biobased Products and Fuels. A Memorandum of Understanding was 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. The agreement was initiated on April 6, 2004 and will run until 2009 unless extended.

A number of contacts with member companies of the Corn Refiners Association have taken place during this reporting period. Interaction continues to address aspects of process modeling and coproduct composition. Results from the wet milling plant trial being conducted in Malaysia in August 2005 will be presented at a future meeting of the association technical committee.


5.Describe the major accomplishments over the life of the project, including their predicted or actual impact.
This project is in its first year and therefore the major accomplishments and predicted impact over the life of the project would be the same as those listed in Question 4a and 4b above.


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?
Question 6:

Patent was issued for technology developed to recover germ and pericarp fiber during a modified dry grind ethanol process. This patent has received significant interest from the ethanol industry and it is expected that it will be licensed in the next 1-2 years.

Researchers from the CRIS met with scientists from one of the world’s largest enzyme companies three times during the year (January, April, and June), to transfer technology on enzyme based corn processing and to discuss new enzyme strategies for recovering value added coproducts during corn processing.

Researcher from the CRIS project visited 4 Midwest dry grind ethanol facilities to discuss research results of enzyme based corn process and the value of germ recovered from modified dry grind corn processing.

Researcher from the CRIS project visited with faculty and students at the University of Minnesota to discuss ongoing research projects. Information was exchanged related to modified corn processing and coproduct values. Ideas for potential collaborative projects were exchanged.

Research from the CRIS project visited with representatives of Grain Value, LLC to discuss engineering and cost models of corn dry-grind processing in AspenPlus and SuperPro Designer.

The process and cost models developed for dry grind processing and corn wet milling were given out by requests 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).
David Johnston. Enzymatic Technologies for Milling Grains and Producing Biobased Products and Fuels. Genencor International, Palo Alto, CA, January 2005.

David B. Johnston, Andrew J. McAloon, Robert A. Moreau, Kevin B. Hicks and Vijay Singh. Composition and Economic Comparison of Germ Fractions Derived from Modified Corn Processing Technologies presentation at FEW in Kansas City.

Yadav, M. P., Johnston, D. B., Hicks, K. B., and Nothnagel, E. A. Structure/function relationships between corn fiber gums and their emulsifying properties, Department of Botany and Plant Sciences, University of California, Riverside, CA, March 18, 2005 (Invited seminar).

Murthy, G.S., Johnston, D.B., Rausch, K.D., Tumbleson, M.E., Singh, V. 2005. Strategies to improve fermentation characteristics of degermed corn flour. Paper No. 057048. American Society of Agricultural Engineers, St. Joseph, MI.

Wang, P., Xu, L., Johnston, D.B., Rausch, K.D., Tumbleson, M.E. and Singh, V. 2005. Enzymatic dry grind corn process using a new enzyme. Paper No. 056117. American Society of Agricultural Engineers, St. Joseph, MI.


Last Modified: 9/2/2014
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