Progress 01/05/00 to 06/15/04
Outputs
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? Developing new byproducts as outlets for the 5 million tons of waste residue generated annually by the Florida citrus processing industry is critical to industry health. With low profit margins from juice sales and increased competition from foreign imports, the revenue obtained by production of waste stream byproducts is becoming increasingly important for the Florida Citrus Industry to remain profitable. Currently, most citrus processing waste is dried to make citrus pulp pellets for use as cattle feed. Unfortunately, citrus pulp pellets have not had sufficient value to cover production and transportation costs for over 6 years. The cost and environmental impact of putting this waste in landfills eliminates this as an option if the citrus industry is to remain profitable and survive. The citrus waste
stream contains numerous phytochemicals with demonstrated human health benefits, and large quantities of carbohydrates in the form of simple sugars, pectin and other polysaccharides. The development of new by-products from the citrus processing waste stream via integrated and economical new processes offers a tremendous opportunity to increase crop value. The investigators will characterize the structure and functional properties of the carbohydrate fraction. They will develop new and use existing procedures including chemical, physical or enzymatic processes to modify and produce polysaccharides, value added polymers, or resins with unique functional properties, either isolated or while still contained in the bulk waste stream residue. These new materials will be tested for use in industrial applications requiring metal chelating and ion-exchange materials, as additives to modify building and construction materials, as paper additives, other non-food related applications.
Economically viable and environmentally friendly processes will be stressed. This work is relevant to citrus growers and citrus juice processors who will benefit by realizing increased value for their products. The impact of this project for the citrus industry is increased crop value, better competitiveness for U.S. citrus products, and a reduction in biomass pollution and disposal problems. Other customers of the research are industrial manufacturers of building and construction materials, paper additives, and industries requiring materials for waste water remediation that are environmentally friendly. It is also possible that the applications developed by this project to produce new by-products from the citrus waste stream could be applied to other fruit and vegetable processing waste streams rich in polysaccharides, such as those produced by the apple and sugar beet industry. This project is 100% devoted to addressing Component 2 (New Processes, New Uses, and Value-Added Foods and
Biobased Products) of NP 306, 'Quality and Utilization of Agricultural Products'. We seek to enhance the value and competitiveness of the U.S. citrus industry by developing new by-products and industrial applications for existing and newly developed citrus by-products through the use of economical, environmentally benign, and efficient processing methods. 2. List the milestones (indicators of progress) from your Project Plan. Year 1 (FY 2004) Investigate effects of enzyme, acid and base treatments on hydrolyzing citrus waste polysaccharides to simple sugars, in modifying functionality of pectin, and effectiveness in releasing pectin from cellulose. Show feasibility of isolating non-calcium sensitive pectins in yields greater than 15 % from fresh peel. Separate and characterize multiple forms of pectinmethylesterase (PME) enzymes from citrus, begin determining their structural modification of pectin. Begin accumulation of PME modified pectins and preliminary investigations of
functional properties. Establish methodology and instrumentation for studying physical properties of new products from citrus peel. Year 2 (FY 2005) Demonstrate feasibility of ultrafiltration or an alternative separation system to isolate soluble sugars, pectin, or other carbohydrates from solid residues and initiate technology transfer. Characterize pectins isolated from fresh peel and initiate technology transfer. Determination of PME structural modification of pectin and accumulation of PME modified pectins. Scale up on promising pectin modifications with chemicals to provide testing material to industry. Further chemical modification of citrus peel materials and testing of new products. Year 3 (FY 2006) Further modifications on pectin, using enzymes, acid, base, and crosslinking of resins. Complete studies on disaggregation using proteases and surface-active agents and continue technology transfer. Further structural modification of pectin with PME, accumulation of PME modified
pectins, and determination of their functional properties and technology transfer. Scale up of pectin modifications, provide test materials to industry partners. Continue modification of citrus peel and testing and initiate technology transfer. Year 4 (FY 2007) Continue with resin crosslinking studies and continue technology transfer. Incorporate disaggregation improvements into isolation process and continue technology transfer. Continue determination of pectin structural modifications and functional properties, continue scale up production of modified pectin materials, and provide test materials to industry partners. Optimize modification of citrus peel and testing and initiate technology transfer 3. Milestones: A. List the milestones that were scheduled to be addressed in FY 2004. How many milestones did you fully or substantially meet in FY 2004 and indicate which ones were not fully or substantially met, briefly explain why not, and your plans to do so. FY 2004 Investigate
effects of enzyme, acid and base treatments on hydrolyzing citrus waste polysaccharides to simple sugars, in modifying functionality of pectin, and effectiveness in releasing pectin from cellulose. Show feasibility of isolating non-calcium sensitive pectins in yields greater than 15 % from fresh peel. Separate and characterize multiple PMEs, begin determining their structural modification of pectin. Begin accumulation of PME modified pectins and preliminary investigations of functional properties Establish methodology and instrumentation for studying physical properties of new products from citrus peel. Completion: The milestones were fully or substantially met in FY2004. B. List the milestones that you expect to address over the next 3 years (FY 2005, 2006, 2007). What do you expect to accomplish, year by year, over the next 3 years under each milestone? Project Number 6621-41000-008-00D, 'Enhanced Utilization of Pectin and Galacturonic Acid Derivatives' has ended and was replaced
by Project Number 6621-41000-011-00D, 'Enhanced Utilization of Carbohydrates and Polysaccharides from Citrus Processing Waste Streams'. The following milestones we expect to address in the next 3 years: FY 2005 Milestone: Demonstrate feasibility of ultrafiltration or an alternative separation system to isolate soluble sugars, pectin, or other carbohydrates from solid residues and initiate technology transfer. Accomplishment: Crude citrus waste stream extracts produced by acid and base treatments will be separated and purified by treatments using various sized ultrafiltration or nanofiltration membranes and the extracts characterized by molecular weight. Demonstrate that simple sugars in hydrolyzed citrus waste streams can be separated from limonene containing material for use as a fermentation feed for ethanol production. Milestone: Characterize pectins isolated from fresh peel and initiate technology transfer. Accomplishment: Isolated pectins will be characterized for molecular
weight distribution, viscosity, and other rheological parameters. Milestone: Determination of PME structural modification of pectin and accumulation of PME modified pectins. Accomplishment: Pectin extracts from citrus will be modified by isolated PME enzymes and characterized for molecular weight, degree of esterification, ion-exchange, water holding, and rheological properties. Begin structural mapping of pectin after treatment with the fourth chromatographic form of pectin methylesterase from citrus peel, which is currently uncharacterized and continue with structural mapping of other enzyme modified pectins. Relate functional properties of enzyme-modified pectins to mapped structural features. Milestone: Scale up on promising pectin modifications with chemicals to provide testing material to industry. Accomplishment: Development of pilot scale batch processes for modified pectins to produce one-pound quantities for industry partners to test in applications. Milestone: Further
chemical modification of citrus peel materials and testing new products. Accomplishment: Development of low cost process for modifying pectins for suspending aid and other applications. Suspension properties will be quantified by rheological measurements for patent and publication purposes. In addition, separate investigations will be undertaken to perform modifications of citrus peel for other applications, such as cement additives, use in paper chemical applications, concrete additives, chelating agents and water absorption applications. FY 2006 Milestone: Further modifications on pectin, using enzymes, acid, base, and crosslinking of resins. Accomplishment: Test modified pectin with strong and weak bases and acids at different temperatures to produce pectin extracts with different molecular weights and rheological properties. Modify pectin using PME enzymes isolated from citrus as they become available. Milestone: Complete studies on disaggregation using proteases and surface-
active agents and continue technology transfer. Accomplishment: Show utility of using commercially available proteases and surfactants for preventing aggregation of pectins to improve molecular weight determinations and aid utility as a suspending aid. Milestone: Further structural modification of pectin with PME, accumulation of PME modified pectins, and determination of their functional properties and technology transfer. Accomplishment: Further structural mapping of pectin after treatment with the fourth chromatographic form of pectin methylesterase from citrus peel, which is currently uncharacterized and continue with structural mapping of other enzyme-modified pectins. Relate functional properties of enzyme-modified pectins to mapped structural features. Milestone: Scale up of pectin modifications, provide test materials to industry partners. Accomplishment: Adjust conditions for pectin modifications that have promising functional characteristics to allow pilot scale
production of modified materials and supply them to industry partners for testing in applications. Milestone: Continue modification of citrus peel and testing and initiate technology transfer. Accomplishment: Adjust conditions for pectin and polysaccharide modifications so modifications can be done without prior separation from other components, producing crude and inexpensive products for industrial use. FY 2007 Milestone: Continue with resin crosslinking studies and continue technology transfer. Accomplishment: Test commercially available crosslinking agents and develop stable polysaccharide gel bead for use as ion exchange resin for heavy metal recovery from waste waters. Milestone: Incorporate disaggregation improvements into isolation process and continue technology transfer. Accomplishment: Demonstrate utility and economic benefits of incorporating disaggregation aids into isolation of pectin and other polysaccharides from citrus processing waste stream. Milestone: Continue
determination of pectin structural modifications and functional properties, continue scale up production of modified pectin materials, and provide test materials to industry partners. Accomplishment: Characterize modifications to pectin structure with PME enzymes and demonstrate utility in industrial applications. Adjust conditions for pectin modifications that have promising functional characteristics to allow pilot scale production of modified materials and supply them to industry partners for testing in applications. Milestone: Optimize modification of citrus peel and testing and initiate technology transfer. Accomplishment: Continue adjusting conditions for pectin and polysaccharide modifications so modifications can be done without prior separation from other components, producing crude and inexpensive products for industrial use. Demonstrate utility of crude modified polysaccharide complex in industrial applications such as in paper and building material additives. 4. What
were the most significant accomplishments this past year? A. Single most significant accomplishment during FY 2004: Progress was made in commercial scale up of a previously developed laboratory scale process for conversion of citrus waste carbohydrates to ethanol for use as a biofuel. Conversion of citrus peel waste to ethanol would provide a more economic by-product than the current situation where peel is converted to cattle feed. The process involves enzyme hydrolysis of the complex carbohydrates to simple sugars, which are then fermented to ethanol. This is a process that is easily scalable for the enzymatic hydrolysis step to convert citrus complex carbohydrates into a sugar rich liquid stream for fermentation to ethanol, using a large portion of peel waste. B. Other Significant Accomplishment(s), if any. The effect of a thermally tolerant form of PME on the structure of a non- calcium sensitive pectin has been reported. Determination of the size of demethylated blocks
incorporated into the pectin molecule under different physical conditions indicate that it can be manipulated to produce variable functional properties dependent on the reaction conditions chosen. Properties that can be tailered include metal binding (waste wated remediation), water holding capcity and porosity (drug delivery, building materials) and utility as a suspension acid (acid dairy products and other industrial applications). 5. Describe the major accomplishments over the life of the project, including their predicted or actual impact. Methodology was developed and improved for quantification of individual galacturonic acid oliogmers separated from pectinaceous material. Latest developments allow separation of pectic fragments containing more than 70 galacturonic acid units. This procedure facilitates mapping of pectin structure and modifications made to pectin with treatment with enzymes and chemicals. It allows for determining functional properties related to introduced
structural features. Three of the four isozymes of PME present in citrus fruit peel have been prepared as monocomponent preparations and characterized for their physical and biochemical properties. Conditions have been described that favor activity of one isoform over the others which will allow for their use in tailoring the structural and functional properties of modified pectin or fruit peel fragments for industrial utilization. Assay procedure for determination of major component of citrus peel, pectin, was developed. This will assist in quantitation of this important component as new products and processes are developed for its modification and release from peel. This technique could be of value in all future products involving pectin in citrus peel. Demonstrated non-calcium sensitive pectins could be isolated from washed orange peel in yields representing approximately 15% on a dry weight basis. This is approximately half of the total available pectin present in the peel.
These pectins were extracted under relatively mild reaction conditions which simplify the process, is more environmentally friendly and aids in technology transfer. 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? Established CRADA with local industry partner interested in commercial development of converting waste citrus carbohydrates into ethanol for use as a biofuel. It is expected the technology will become available towards the end of FY 2006. 7. List your most important publications in the popular press and presentations to organizations and articles written about your work. FOX 13 News of Tampa, FL visited the laboratory to tape an interview with demonstration by Dr. Widmer on conversion of citrus waste to ethanol for use as a biofuel. May,
2004.
Impacts
(N/A)
Publications
- Luzio, G.A. 2003. Effect of block deesterification on the pseudoplastic properties of pectin. Proceedings Of Florida State Horticultural Society. 116:425-429.
- CAMERON, R.G., HOTCHKISS, A.T., KAUFFMAN, S.W., GROHMANN, K. UTILIZATION OF AN EVAPORATIVE LIGHT SCATTERING DETECTOR FOR HIGH PERFORMANCE SIZE EXCLUSION CHROMATOGRAPHY OF GALACTURONIC ACID OLIGOMERS. JOURNAL OF CHROMATOGRAPHY A. 2003. v. 1011(1-2). p. 227-231.
- Cameron, R.G., Grohmann, K., Hotchkiss, A.T. 2003. Separation and detection of oligogalacturonides. Proceedings Of Florida State Horticultural Society. 116:413-417.
- CAMERON, R.G., SAVARY, B.J., HOTCHKISS, A.T., FISHMAN, M.L., CHAU, H.K., BAKER, R.A., GROHMANN, K. SEPARATION AND CHARACTERIZATION OF A SALT- DEPENDENT PECTIN METHYLESTERASE FROM CITRUS SINENSIS VAR. VALENCIA FRUIT TISSUE. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY. 2003. v. 51(7). p. 2070-2075.
- Luzio, G.A. 2003. Strategic approach toward industrial utilization of citrus peel. Subtropical Technology Conference Proceedings. 54:41.
- Cameron, R.G., Kauffman, S.W., Grohmann, K. 2003. Modification, separation and detection of oligogalacturonides. Subtropical Technology Conference Proceedings. 54:40.
- Widmer, W.W. 2004. Health benefits of citrus polysaccharides. American Chemical Society National Meeting. Paper No. AGFD 143.
- Luzio, G.A. 2004. Molecular size analysis of extracted citrus pectins by multiangle light scattering. Annual Meeting of the Institute of Food Technologists. Book of Abstracts. p. 147. Paper No. 56-6.
- Cameron, R.G., Grohmann, K. 2004. Mapping demethylated block size and distribution in pectin from citrus processing waste. Annual Meeting of the Institute of Food Technologists. Book of Abstracts. p. 147. Paper No. 56-5.
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Progress 10/01/02 to 09/30/03
Outputs
1. What major problem or issue is being resolved and how are you resolving it? In Florida greater than 80% of the citrus fruit produced are processed into juice products. In juice processing, approximately one half of a citrus fruit is waste and the Florida citrus juice processing industry generates more than 1 million tons/yr of dried waste material. Annual production of dried residues from apple and sugar beet processing in the United States generate at least another 1 million tons/yr of dried waste material. Traditional use for these residues is as cattle feed which currently does not have sufficient value to cover the production/transportation costs. These materials are rich in pectin and other biopolymers. World pectin production for food, the major use, has been stagnating at approximately 30,000 tons/yr because markets in marmalade and jam production are mature with very slow growth. Demand for pectin is only about 10 percent of the amount which could be
generated from this resource. Markets for the other biopolymers present in citrus, which comprise approximately 30% of the residue by dry weight, remain undeveloped. New products and new markets need to be developed for pectin and the other nontoxic, biodegradable polymers plentiful in citrus peel waste streams to increase the value of the citrus crop. Citrus peel waste and similar co-products represent a large reservoir of inexpensive raw material for the production of pectin and other biopolymers and their derivatives. New products which will be developed from this research will include, but are not limited to, new sequestering agents, cation exchange resins and coagulants. The processes for water treatment and recovery of the heavy metals using these agents will be developed and/or evaluated. 2. How serious is the problem? Why does it matter? In excess of 2 million tons of dried waste residue rich in pectin and other cell wall byproducts from the citrus, apple and beet sugar
industries are being underutilized as cattle feed. New, environmentally friendly products derived from these byproduct streams for water treatment, metal recovery, and other industrial applications will increase revenues and profits to the citrus, apple, and beet sugar industries. Since pectin, other biopolymers, and related derivatives from these products are biodegradable and non-toxic, the public will benefit by the introduction of these materials. 3. How does it relate to the National Program(s) and National Program Component(s) to which it has been assigned? This research is highly relevant to National Program Area 306, Quality and Utilization of Agricultural Products, addressing the issue of expanding domestic and global market opportunities through the development of value-added food and nonfood products and processes. As a means to develop new value-added industrial products from an underutilized resource, it directly supports the second Research Component of 306, New
Processes, New Uses, and Value-Added Biobased Products. This project will collaborate with the personnel of Project Number 1935-41000-049-00, Sustainable Technologies For Polysaccharide- Based Functional Foods and Biobased Products, at the USDA/ARS Eastern Regional Research Laboratory. 4. What were the most significant accomplishments this past year? A. Single Most Significant Accomplishment during FY 2003: A low cost approach toward modification and processing of pectins in citrus peel will be beneficial in being able to add additional functionality to polysaccharide products and expand into new markets with citrus byproducts. Work at the Citrus and Subtropical Laboratory was done to demonstrate a low cost process able to modify pectins while still in citrus peel for use as a suspending aid in industrial applications. The modified peel preparation can be used as a direct replacement for Xanthan gum. The impact could be an alternative material for use in industrial applications
such as dispersing and suspending solutions and emulsions of agrochemicals, pulp and paper manufacturing water treatments, formulations for metal treatments, and suspensions and lubrication muds for oil drilling. B. Other Significant Accomplishment(s), if any: The functional properties of pectin that make it useful for industrial and food applications are influenced by molecular size, structure, and chemical composition. At the Citrus and Subtropical Products Laboratory, Winter Haven, Florida in cooperation with Dr. Arland Hotchkiss (USDA, ARS, Eastern Regional Research Center, Wyndmoor, PA), a chromatographic method was developed that can resolve a much greater range of pectin fragments than previously possible. Separation and quantification of these fragments enables us to make determinations on the structural characteristics resulting from enzymatic treatments. Through measurement of structural characteristics, we will be able to determine the types of enzymatic conditions that
are required to produce materials with various specific desirable functional properties for use as additives in food and industrial products. B. Other Significant Accomplishment(s), if any (continued): Purified pectin fragments are required for use as standards to calibrate the instruments used to separate and quantify experimental pectin mixtures. A chromatography system allowing us to separate and collect the individual pectic fragments was assembled at the Citrus and Subtropical Products Laboratory. A method for separating sufficient quantities of pectin fragments was optimized and useable quantities of each fragment are being collected. Using the pectin fragment standards generated, quantities of individual pectic fragments in experimental extracts can be determined, their composition characterized, and enzyme treatment conditions optimized to yield pectin samples with desired structural/functional properties. 5. Describe the major accomplishments over the life of the project,
including their predicted or actual impact. A chromatography method was developed to describe alterations made to the pectin component found in citrus fruit peel at the Citrus and Subtropical Products Laboratory. This and other chemical methods have been modified to analyze pectin. These techniques enable exploration of relationships between pectin structural and functional properties that would be desirable for its use in waste water treatment. 6. What do you expect to accomplish, year by year, over the next 3 years? FY2004. Preparations derived from citrus byproducts, rich in pectin, will be deesterified to increase the concentration of carboxylic acid groups, increasing the suspending capacity, sequestering and metal binding capacity of these preparations. The most effective/economical procedure for converting pectin rich byproducts to functional industrial products will be determined, characterized and evaluated for effectiveness. Continue development of low cost processes for
modifying pectins for a suspending aid and other applications. The art has been reduced to practice but process optimization is required. Plan is to optimize acid extraction conditions as well as enzyme conditions to yield the best suspension and yield point properties. In addition suspension properties must be quantified by rheological measurements for patent and publication purpose. Additionally citrus extracts will be fractionated based on molecular weight using size exclusion filtration to be provided to partners with which we have material transfer agreements for testing as additives in building materials. The HPLC method to separate and quantify oligogalacturonic acid fragments will be calibrated and peel fractions analyzed for composition. FY2005. Pectin fine-structure from crude fruit peel material will be evaluated and compared to enzymatically modified peel. Efforts will be made to optimize product stability. Reducing groups at the end of the chain are a source of
instability during thermal and alkaline degradation of polysaccharide fragments. These groups can be stabilized by oxidation to acid or reduction to alcohol groups. Oxidizing and reducing agents or catalytic reactions will be investigated and the most promising ones selected for further development. Ion-exchange materials will be prepared from polysaccharide fragments. Polysaccharides can be cross- linked by formation of ester, amide or ether linkages. Several cross- linking agents will be investigated and the most promising ones selected for preparation of larger quantities of ion exchange materials. Process scale up on pilot plant scale will proceed for suspension process and target applications for suspension aid will be selected such as for drilling muds and waste treatment. In addition, separate investigations will be undertaken to perform modifications of citrus peel for other applications , such as cement additives, use in paper chemical applications, concrete additives,
chelating agents and water absorption applications. FY2006. Enzymatically modified fruit peel will be evaluated for improved functionality. Work on suspension aid will continue. Evaluate stabilized oligogalacturonic acids and developed ion-exchange beads for absorption of heavy metal ions. Capacity and selectivity of these ion exchange resins and sequestering agents will be evaluated for copper, lead, cadmium, zinc and other ions. Solubility of metal complexes and elution of bound ions will be investigated as well. Cost effectiveness and environmental benefits of these novel exchange materials will be evaluated. 7. 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? Two CRIS scientists gave presentations at a Citrus Processing and Technology
Conference attended by industry, consultants, and university scientists. CRIS scientist gave presentation at the Florida Technology Transfer Showcase (attended by agricultural processors, growers, consultants and scientists). Citrus peel preparations have been sent to an adhesive company and cement company for examination on their effect on adhesive and cement properties. 8. List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: This does not replace your peer-reviewed publications listed below). "Utilization of an evaporative light scattering detector for HPSEC of galacturonic acid oligamers" and "By-products from citrus waste steam polysaccharrides" presented at the Citrus Processing and Technology Conference, Lake Alfred, FL, October 17, 2002 (attended by citrus processors, growers, consultants and scientists and published in their proceedings). "New products from citrus juice processing residue"
presented at the Florida Technology Transfer Showcase, Fort Pierce, FL, October 29, 2002. (attended by agricultural processors, growers, consultants and scientists and published on CDROM).
Impacts
(N/A)
Publications
- Widmer, W.W. Dietary fiber content in fresh citrus. Proceedings of the Florida State Horticultural Society. 2002. v. 115. p. 301-303.
- Widmer, W.W. Dietary fiber and other products from complex carbohydrates in citrus processing waste. Annual Meeting of Institute of Food Technologists. 2003. p. 46. Abstract No. 19-6.
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Progress 10/01/01 to 09/30/02
Outputs
1. What major problem or issue is being resolved and how are you resolving it? In Florida greater than 80% of the citrus fruit produced are processed into juice products. In juice processing, approximately one half of a citrus fruit is waste and the Florida citrus juice processing industry generates more than 1 million tons/yr of dried waste material. Annual production of dried residues from apple and sugar beet processing in the United States generate at least another 1 million tons/yr of dried waste material. Traditional use for these residues is as cattle feed which currently does not have sufficient value to cover the production/transportation costs. These materials are rich in pectin and other biopolymers. World pectin production for food, the major use, has been stagnating at approximately 30,000 tons/yr because markets in marmalade and jam production are mature with very slow growth. Demand for pectin is only about 10 percent of the amount which could be
generated from this resource. Markets for the other biopolymers present in citrus, which comprise approximately 30% of the residue by dry weight, remain undeveloped. New products and new markets need to be developed for pectin and the other non-toxic, biodegradable polymers plentiful in citrus peel waste streams to increase the value of the citrus crop. Citrus peel waste and similar co-products represent a large reservoir of inexpensive raw material for the production of pectin and other biopolymers and their derivatives. New products which will be developed from this research will include, but are not limited to, new sequestering agents, cation-exchange resins and coagulants. The processes for water treatment and recovery of the heavy metals using these agents will be developed and/or evaluated. Currently, other ion-exchange resins and chelators are used for waste water treatment which are expensive and have environmental issues. Pectin from citrus peel has chemical properties
that would allow it to serve as a cation-exchanger, would be less expensive than current exchangers and environmentally friendly. As a biobased product it would generate more revenue for the citrus industry than cattle feed. 2. How serious is the problem? Why does it matter? In excess of 2 million tons of dried waste residue rich in pectin and other cell wall byproducts from the citrus, apple and beet sugar industries are being underutilized as cattle feed. New, environmentally friendly products derived from these byproduct streams for water treatment, metal recovery, and other industrial applications will increase revenues and profits to the citrus, apple, and beet sugar industries. Since pectin, other biopolymers, and related derivatives from these products are biodegradable and non-toxic, the public will benefit by the introduction of these materials. 3. How does it relate to the national Program(s) and National Program Component(s) to which it has been assigned? This research
is highly relevant to National Program Area 306, Quality and Utilization of Agricultural Products, addressing the issue of expanding domestic and global market opportunities through the development of value-added food and nonfood products and processes. As a means to develop new value-added industrial products from an underutilized resource, it directly supports the second Research Component of 306, New Processes, New Uses, and Value-Added Biobased Products. This project will collaborate with the personnel of Project Number 1935-41000-049-00, Sustainable Technologies For Polysaccharide- Based Functional Foods and Biobased Products, at the USDA/ARS Eastern Regional Research Laboratory. 4. What was your most significant accomplishment this past year? A. Single Most Significant Accomplishment during FY 2002: A method that allows for accurate profiling of oligogalacturonic fragment quantities produced during enzymatic modification of fruit peel is necessary to evaluate modifications and
property changes made to citrus peel components in order to taylor the pectin molecule for new industrial uses. With just one scientist devoting 20% of his time to this project, a high pressure liquid chromatography method was developed to evaluate fine structure modifications of the pectin components found in fruit peel at the ARS Quality Improvement in Citrus and Subtropical Products Laboratory. This and other chemical methods have been modified to analyze carboxylic acid content and spatial distribution of demethylated blocks of pectin. These techniques enable exploration of relationships between pectin structure and ion exchange, as well as chelation and sequestration properties of metal ions that would be desirable in waste water treatment. B. Other Significant Accomplishment(s), if any: None. 5. Describe your major accomplishments over the life of the project, including their predicted or actual impact? Since this is a new project which does not build on a pre-existing project,
the accomplishments are defined above in the response to Question 4. 6. What do you expect to accomplish, year by year, over the next 3 years? FY2003. Preparations derived from citrus byproducts, rich in pectin, will be deesterified to increase the concentration of carboxylic acid groups, there by increasing the sequestering and metal binding capacity of these preparations. Pectin in citrus processing residues is highly esterified and esterified groups do not bind metal ions. The most effective/economical procedure for converting pectin rich byproducts to functional industrial products will be determined, characterized and evaluated for effectiveness. Effective and economical means to partially depolymerize pectin and other polysaccharides to reduce the viscosity of preparations while maintaining metal binding functionality will be investigated to optimize shipping and storage of potential industrial products. New opportunities for utilization of polysaccharide residues and their
derivatives from citrus processing waste in cement additive formulations will also be investigated. FY2004. Efforts will be made to optimize product stability. Reducing groups at the end of the chain are a source of instability during thermal and alkaline degradation of polysaccharide fragments. These groups can be stabilized by oxidation to acid or reduction to alcohol groups. Oxidizing and reducing agents or catalytic reactions will be investigated and the most promising ones selected for further development. Ion- exchange beads will be prepared from polysaccharide fragments. Polysaccharides can be cross-linked by formation of ester, amide or ether linkages. Insolubilized cross-linked polysaccharides, formed into beads, can be used in ion exchange and metal binding applications. Several cross-linking agents will be investigated and the most promising ones selected for preparation of larger quantities of ion exchange beads. FY2005. Evaluate stabilized oligogalacturonic acids
and developed ion- exchange beads for absorption of heavy metal ions. Capacity and selectivity of these ion-exchange resins and sequestering agents will be evaluated for copper, lead, cadmium, zinc and other ions. Solubility of metal complexes and elution of bound ions will be investigated as well. Cost effectiveness and environmental benefits of these novel exchange materials will be evaluated. 7. What technologies have been transferred and to whom? When is the technology likely to become available to the end user (industry, farmer other scientist)? What are the constraints, if known, to the adoption durability of the technology? No transfer of science/technology has occurred at this time, with the exception of one presentation at the 2001 Subtropical Technology Conference attended by industry, Scientists, and consultants. It is expected that the science will become available to scientists in year two, as publications describing the initial research are released. Transfer of
technology to industry will require evaluation of final product forms, such as ion-exchange beads, which will be accomplished in year three. However, peel preparations have been sent to cement companies for examination of their effect on cement properties. 8. List your most important publications and presentations, and articles written about your work (NOTE: this does not replace your review publications which are listed below) "Purification and characterization of a salt-dependent pectin methylesterase from Valencia fruit rag tissue" presented at the Subtropical Technology Conference, Lake Alfred, FL, October 19, 2001 (attended by citrus processors, growers, consultants and scientists).
Impacts
(N/A)
Publications
- Cameron, R.G., Kauffman, S.W., Grohmann, K. Utilization of an evaporative light scattering detector for HPSEC of galacturonic acid oligomers. 2002. American Society of Plant Biologists. Paper No. 326.
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