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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
2008 Annual Report


1a.Objectives (from AD-416)
The objective of this research project is to develop new, cost effective, alternative methods and engineering processes for corn processing and fractionation using enzymes, immobilized enzymes and other environmentally sustainable processes that maximize the yields of products and co-products (starch, protein, ethanol, oil, and fiber) and increase co-product market diversity and value while eliminating hazardous processing aids, such as sulfites.


1b.Approach (from AD-416)
This project was conceived and developed from the concept of taking a new approach to existing processes with the connecting element being enzymatic application. Many of the milling processes currently in use have been done in a similar fashion for over 100 years. By carefully reexamining what we know and don't know, and what works and what still has room for improvement we can use this to guide research towards beneficial modifications of existing processes and invent completely new design concepts. The experimentation for this project is constructed to cover fundamental research through design and economic assessment. Scale-up studies are incorporated into the plan where appropriate demonstration efforts and material are required. Process modeling and cost analysis are critical elements that are incorporated throughout the project design and are intended to aid in the overall process evaluation and to help identify potential problems early in experimentation.


3.Progress Report
During fiscal year 2008, research was conducted in the area of corn wet milling. Previously we developed and patented an enzymatic corn wet milling process. This process was licensed to Genencor (a Danisco company) and we have continued collaborating on the development and application of this technology. During the year, a month long plant trial was conducted with Genencor in Malaysia at a small corn wet milling facility using Genencor’s second generation enzyme (ProSteep). Additional trials are being planned. If these future trials are as successful as the first, it is likely that wet milling facilities in the US will begin adopting the new technology. This addresses NP306 action plan’s “Component 2, New Processes, New Uses, and Value-Added Foods and Biobased Products.” Specifically it responds to Problem Area 2c. New and Improved Processes and Feedstocks.

Progress was made under 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. During the fiscal year 2008, contacts were made with individuals belonging to members companies of the Corn Refiners Association and with professors at the University of Illinois. These discussions took place at conferences, by telephone and by email. During these conversations, Enzymatic Milling was discussed at length and the possibility of future testing was discussed. This addresses NP306 action plan’s “Component 2, New Processes, New Uses, and Value-Added Foods and Biobased Products.” Specifically it responds to Problem Area 2c. New and Improved Processes and Feedstocks.


4.Accomplishments
1. Production of Astaxanthin from non-starch polysaccharide byproducts: The development of new coproducts using microorganisms to convert lower value material derived from corn based fuel ethanol processes into higher valued products is being investigated as a way to improve the overall economics of fuel ethanol production. Pretreatment and the subsequent enzymatic hydrolysis of the low value corn fiber (CF) and distillers dried grains with solubles (DDGS) derived from corn to ethanol processes were performed. It was found that the hydrolysate obtained with dilute acid pretreatment required dilution before fermentation of the mixed sugars by the yeast Xanthophyllomyces dendrorhous could occur. This yeast can produce significant amounts of Astaxanthin (a valuable carotenoid and antioxidant) when grown under proper conditions. Pretreatment of CF by soaking in ammonia was found not to generate compounds inhibitory to the Astaxanthin fermentation and the hydrolysate could be fermented directly to Astaxanthin. Successful implementation of this technology will potentially improve the corn to ethanol economics and could also help existing ethanol plants transition or bridge the gap to cellulosic ethanol production. This addresses National Program Action Plan: Component 2: New processes, new uses, and value-added biobased products; specifically to Problem Area 2b: New uses for agricultural byproducts because we will convert low value agricultural residues into higher value products.

2. Functional components in corn fiber gum: Corn fiber gum (CFG) is a polysaccharide with commercially useful emulsifying properties (emulsions are mixtures of two unblendable liquids such as oil and water). CFG is made by an alkali extraction of the fiber fractions isolated during corn processing. Research has been ongoing to study and understand the functional properties of CFG. Earlier we determined that CFG is not 100% carbohydrate as most researchers thought, but that it also contains protein and lipid subcomponents. In research conducted this year, we removed a protein rich sub-fraction from the corn fiber gum using chemicals or enzymes. After removal of the protein, the modified corn fiber gum was studied to determine the effects on the emulsifying properties. It was determined that removal of the protein fraction from the corn fiber gum, decreased the emulsifying properties significantly. Identifying that the protein component was partially responsible for the functional properties of corn fiber gum will help to better produce and potentially formulate CFG and protein blends with increased functionality. This addresses National Program 306 Action Plan: Component 2: New processes, new uses, and value-added biobased products; specifically to Problem Area 2b: New uses for agricultural byproducts.

3. Wet Milling Process Model Distribution Researchers working on advanced corn wet-milling research at ERRC and elsewhere had no validated and publicly available wet milling process and cost model with which to understand the operation of current wet mills and to understand how proposed changes in technology might affect existing process. To solve this problem, a publicly available process model was previously developed and made available in several different software programs. Since then it has been requested by many industry engineers and scientists, academic researchers and other federal agencies. During FY 2008 the models was requested and distributed more than 120 times. This addresses NP306 action plan’s “Component 2, New Processes, New Uses, and Value-Added Foods and Biobased Products.” Specifically it responds to Problem Area 2c. New and Improved Processes and Feedstocks.


5.Significant Activities that Support Special Target Populations
None.


6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings2

Review Publications
Mikkonen, K., Yadav, M.P., Cooke, P.H., Willfor, S., Hicks, K.B., Tenkanen, M. 2008. Films from spruce galactoglucomannan blended with poly(vinyl alcohol), corn arabinoxylan and konjac glucomannan. BioResources. 3(1):178-191.

Fu, H., Yadav, M.P., Nothnagel, E.A. 2007. Physcomitrella patens arabinogalactan proteins contain abundant terminal 3-o-methyl-l-rhammosyl residues not found in angiosperms. Planta. 226:1511-1524.

Last Modified: 8/27/2014
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