Progress 12/01/07 to 04/30/10
Outputs
OUTPUTS: Project goals included advancement in the areas of canola meal separation and characterization, protein modification, and use for industrial plastics and composites. Work focused on development and testing of biobased-plastics using canola protein isolates created in our laboratory. Initial experiments were done to produce canola meal and use it to produce flour and protein isolates. Materials were characterized in terms of protein composition (albumins, globulins, glutelins, and prolamins) and functional properties. Canola meal was generated with both screw-pressing and cold-milling techniques to examine the impact of temperature on protein quality. Meals from both processing techniques were solvent-defatted and processed with a modified Osborn sequence extraction method to determine composition and properties. Fractions were analyzed for molecular weight and electrophoretic patterns using SDS-PAGE. Water absorption, fat absorption, and emulsifying activity of each protein fraction were determined. Canola meal proteins were solubilized in a pH 12 solution to separate from other components and precipitated at pH values ranging from 11 to 3 in increments of 1 pH unit. Individual fractions were analyzed for protein content and functional properties. Protein isolates were blended with polyesters and used to prepare injection-molded plastic specimens. The plasticization effect of four types of was investigated. Properties of canola based plastics such as tensile strength, flexural strength, modulus, and water absorption, were studied. Morphology of the fractured surfaces of tensile specimens was examined using scanning electron microscopy. Work was completed to test the impact of protein solubilization pH and precipitation pH on the functional, thermal, and mechanical properties of the protein isolates and the plastic specimens made with them. Protein isolates were prepared and modified with 1-5% concentrations of SDS and SDBS to determine impact on proteins and resulting plastics. Functional property analysis was completed using modified isolates and the plastics produced with those isolates were processed into plastics. Acetylation was also tested as a modification method for proteins. One graduate student and two undergraduate students were trained through this project. Graduate student training included laboratory work, academic coursework, and regular meetings with the project PI. Undergraduate training included supervised laboratory work, close work with a graduate student, and meetings with the project PI. Work was conducted with faculty in the Department of Mechanical Engineering for product formulation and testing. In addition to protein extraction and quantification techniques, the students gained knowledge in the use of extrusion, compression molding, and injection molding. Results were presented at two international meeting and one regional meeting for the ASABE with another abstract submitted and accepted for a future meeting. An invited presentation was also given at a meeting of the AOCS. A PhD dissertation was prepared and successfully defended. One journal manuscript is under review and three others are in preparation. PARTICIPANTS: Individuals: Scott W. Pryor (PI) - Directed and managed project and assisted with design and analysis of experiments. Wajira Asanga Manamperi (graduate student) - designed and carried out most experiments and data analysis. Primary author on most publications. Jaidev Sehrawat (undergraduate researcher) - assisted with some protein isolation work and was primary person for acetylation of canola proteins. Shashika Rathnasinghe (undergraduate researcher) - assisted with canola meal preparation and protein isolations procedures. Michael Fuqua (graduate student) - assisted with extrusion, pelleting, injection molding and mechanical analysis of plastic specimens. Luke Gibbon (undergraduate researcher) - assisted with extrusion, pelleting, injection molding and mechanical analysis of plastic specimens. Partner Organizations: North Dakota State University Collaborators: Sam K. C. Chang (Cereal and Food Sciences) Chad A. Ulven (Mechanical Engineering) Dennis P. Wiesenborn (Agricultural and Biosystems Engineering) Training or Professional Development: One graduate student worked exclusively on this project and was trained in experimental methods and data analysis. Two undergraduate students learned safe laboratory techniques and were exposed to experimental design and data analysis for academic research. TARGET AUDIENCES: Canola producers and processors. Other oilseed processors for food or industrial (e.g. biodiesel) purposes. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The modified Osborn extraction procedure isolated globulins prior to albumins and resulted in an increased globulin yield confirmed through electrophoretic analysis. This modified extraction procedure allowed for improved protein separation and more accurate determination of protein quality and characteristics. Protein yields increased when using cold-milled canola flour over flour from screw-pressed canola. Heat denaturation of proteins that could occur during screw-pressing could reduce protein solubility. By controlling temperature during processing, protein yields are expected to increase. This processing also impacted functional properties. The largest fractions of proteins were extracted at pH values of 11 and less than 7. Proteins precipitated at a pH value of 11 had the highest water absorption and lowest melting point. These proteins were removed from the isolate and the plastics made from the modified isolate were shown to have improved mechanical properties. The use of glycerol as a plasticizer for canola plastics resulted in the highest values for tensile strength, elongation, and toughness. The improvement of these properties was attributed to the good compatibility of glycerol with canola proteins in terms of size and polarity. All plasticizers tested improved the water resistance of test specimens. The highest flexural strength and modulus were obtained using polyvinyl alcohol as a plasticizer. Fracture morphology revealed that specimens plasticized with glycerol, sorbitol, and polyethylene glycol were homogeneously dispersed and showed more ductile behavior compared to unplasticized specimens. Use of PVA as a plasticizer resulted in more brittle plastic specimens. Incorporation of other plasticizers improved the toughness, ductility, and elongation of protein-based plastic specimens. Solubilization and precipitation pH conditions were shown to have a significant impact on protein yields and the properties of the proteins and plastics on quality of plastics from protein isolates was completed. Results showed that maximum protein yields were obtained in the region surrounding solubilization and precipitation pH values of 12.5 and 4.5, respectively. Mechanical properties of plastics prepared with these isolates showed different trends however with maximum tensile strengths and elongation values achieved with proteins isolated using solubilization and precipitation pH values near 1.5 and 5.5, respectively. When optimizing for tensile strength, toughness, and elongation those values increased by 160%, 270% and 930%, respectively, over what was seen at maximum yield conditions; these gains were achieved with less than a 6% reduction in yield. Protein modification via SDS and sodium SDBS were shown to increase the toughness, tensile strength, and modulus of plastic specimens by up to 64, 41, and 52% respectively over those prepared with standard isolates. Elongation and water resistance, however, were generally insensitive to the SDS and SDBS modification. Acetylation increased water absorption, fat absorption and emulsification of canola protein isolates.
Publications
- Manamperi, W.A. 2010. Canola Meal Fractionation and Utilization for Protein-Based Thermoplastics, PhD dissertation, Fargo, ND, North Dakota State University, Department of Agricultural and Biosystems Engineering
- Manamperi, W.A., C.A. Ulven, K.C. Chang, and S. W. Pryor 2010. Plastics from an Improved Canola Protein Isolate: Preparation and Properties, Journal of the American Oil Chemists' Society (in review).
- Sehrawat, J., Manamperi, W.A., and S. W. Pryor, 2010. Preparation of plastics from acetylated canola proteins, 2010 ASABE Annual International Meeting, Pittsburgh, Pennsylavnia, June 20-23, 2010.
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Progress 12/01/08 to 11/30/09
Outputs
OUTPUTS: Project goals included advancement in the areas of canola meal separation and characterization, protein modification, and use for industrial plastics and composites. Work during this period has focused on development and testing of bioplastics using canola protein isolates created in our laboratory. Canola meal protein isolates were blended with polyesters and used to prepare injection-molded plastic specimens. The plasticization effect of four types of plasticizers (glycerol, sorbitol, polyethylene glycol, and polyvinyl alcohol) was investigated. Properties of canola based plastics such as tensile strength, flexural strength, modulus, and water absorption, were studied. Morphology of the fractured surfaces of tensile specimens was examined using scanning electron microscopy. Work was also completed to test the impact of processing conditions for protein isolate formation on the functional, thermal, and mechanical properties of the protein isolates and the plastic specimens made with them. The specific conditions tested were the protein solubilization pH and precipitation pH. One graduate student is being trained through this project. Two undergraduate students have also gotten laboratory work experience. Graduate student training has included laboratory work, academic coursework, and regular meetings with the project PI. Undergraduate training has including supervised laboratory work, close work with a graduate student, and meetings with the project PI. Work has also been conducted with faculty in the department of Mechanical Engineering and Applied Mechanics for product formulation and testing. In addition to protein extraction and quantification techniques, the students have gained knowledge in the use of extrusion, compression molding, and injection molding. Results have been presented at one international meeting for the American Society of Agricultural and Biological Engineers and at another meeting of the American Oil Chemists Society. PARTICIPANTS: Scott W. Pryor (PI) Wajira Asanga Manamperi (graduate student) Jaidev Sehrawat (undergraduate student) Shashika Rathnasinghe (undergraduate student) Chad Ulven (collaborator) K.C. Chang (co-PI) TARGET AUDIENCES: Target audience for this research would be processors of oilseed crops including, but not limited to, canola. By extension, agricultural producers of oilseed crops and industries that utilize oilseed meal (especially those that would use these for food or industrial products) are impacted. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Plasticized specimens showed a ductile type of fracture where as the specimens produced without plasticizers showed a brittle failure. The use of glycerol as a plasticizer resulted in the highest values for tensile strength, elongation, and toughness. The improvement of these properties could be attributed to the good compatibility of glycerol with canola proteins in terms of size and polarity. All plasticizers improved the water resistance of test specimens. The highest flexural strength and modulus were obtained using polyvinyl alcohol (PVA) as a plasticizer. Fracture morphology revealed that specimens plasticized with glycerol, sorbitol, and polyethylene glycol were homogeneously dispersed and also showed more ductile behavior compared to unplasticized specimens. All of the plasticizers were found to yield some improvements except for PVA. Use of PVA as a plasticizer resulted in more brittle plastic specimens as indicated by the higher tensile and flexural moduli. PVA was found not to be a suitable plasticizer for canola protein-based plastics under the conditions used. Overall, incorporation of plasticizers improved the toughness, ductility, and elongation of the protein-based plastic specimens compared to the unplasticized specimens. Preliminary analysis of data from the experiments examining the impact of solubilization and precipitation pH on quality of plastics from protein isolates was completed. Results confirmed previous findings that maximum protein yields were obtained at solubilization and precipitation pH values near 12.5 and 4.5, respectively. Properties of plastics prepared with isolates showed different trends however with maximum tensile strengths and elongation values achieved with proteins isolated using solubilization and precipitation pH values near 1.5 and 5.5, respectively. This indicates that processors wishing to maximize yields when preparing protein isolates are manufacturing an ingredient that may result in non-optimal properties of the final product. Some sacrifice in yield may lead to improvements in versatility and value of the final product.
Publications
- Manamperi, W.A., Chang, K.C. and Pryor S.W. 2009. Sequential Extraction of Canola Meal Proteins and Preparation of Plastic Specimens Using Improved Protein Isolates, Journal of the American Oil Chemists' Society (submitted Sept 2009- accepted pending revision).
- Manamperi, W.A., J. Sehrawat, M. Fuqua, C. Ulven, S. Pryor, 2009. Influence of Plasticizers on Properties of Polymers Made from Canola Protein Polyester Blends, Paper No. 09-6327. ASABE International Meeting. Reno, NV, June 21-24, 2009.
- Kram, J.W. 2008. Plastics from the Prairie. Biomass Magazine, Grand Forks, ND. November 2008.
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Progress 12/01/07 to 11/30/08
Outputs
OUTPUTS: Initial project goals included advancement in the areas of canola meal separation and characterization, protein modification, and use for industrial plastics and composites. Experiments have been completed to use canola meal to produce flour and protein isolates. These materials have been tested in bioplastics and biocomposites. Work has also been completed to characterize these materials in terms of protein composition (albumins, globulins, glutelins, and prolamins). Raw materials (i.e. canola meal flour and protein isolates) as well as protein components have been tested for functional properties that may be useful for predicting performance in plastic or composite materials. Canola meal was generated with both a traditional screw-pressing and cold-milling techniques to examine the impact of processing temperature on canola protein quality. Meals from both processing techniques were solvent-defatted and processed with a conventional Osborn sequence extraction method to determine albumin, globulin, glutelin, and prolamin protein contents and properties. An alteration of this extraction procedure was also used to improve isolation and separation of these components. All fractions were analyzed for their molecular weight and electrophoretic patterns using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Selected functional properties (water absorption, fat absorption, and emulsifying activity) of each protein fraction were determined. Hexane-defatted canola meal from screw-pressed raw canola seeds was solubilized in a sodium hydroxide solution (pH 12) to extract proteins. After centrifugation, the supernatant was subjected to sequential protein precipitation at pH values ranging from 11 to 3 in increments of 1 pH unit. Weight distribution of proteins precipitated at different pH values was analyzed and functional properties of those fractions were determined. One graduate student is being trained through this project. Training has included laboratory work, academic coursework, and regular meetings with the project PI. Work has also been conducted with faculty in the department of Mechanical Engineering and Applied Mechanics for product formulation and testing. In addition to protein extraction and quantification techniques, the student is gaining knowledge in the use of extrusion, compression molding, and injection molding. Results have been presented at one international meeting and one regional meeting for the American Society of Agricultural and Biological Engineers. PARTICIPANTS: Scott W. Pryor is the PI for the project and has provided primary oversight for the work and has taken responsibility for progress of research and the graduate student. Sam K.C. Chang is a co-PI for the project and has given assistance on some protein extraction and characterization methods. Chad Ulven is a collaborator from the NDSU Mechanical Engineering department. He and/or his students have assisted in training the graduate student to produce plastic and composite specimens from the isolated canola proteins using extrusion, compression molding, and injection molding techniques. Dennis Wiesenborn is a collaborator from the NDSU Agricultural and Biosystems Engineering and has assisted primarily in review of manuscripts. Wajira Asanga Manamperi is the graduate student working on the project and is pursuing a Ph.D. in Agricultural and Biosystems Engineering. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The altered Osborn extraction sequence isolated globulins prior to albumins and resulted in an increased globulin yield confirmed through electrophoretic analysis. Native salts in canola meal flour were responsible for co-extraction of globulins with the albumin fraction when using the conventional Osborn extraction method. This modified extraction procedure allowed for improved protein separation and more accurate determination of protein quality and characteristics. The higher quantities of globulins that were obtained using the modified extraction method agree with the other published reports stating globulins (cruciferin) constitute the largest fraction of canola protein. Overall protein yields increased when using cold-milled canola flour when compared to flour from screw-pressed canola seeds. Heat denaturation of proteins that could occur during screw-pressing could reduce protein solubility. By controlling temperature during processing, protein yields are expected to increase. This processing also impacted functional properties. At least one protein fraction showed significant differences between meal generated from screw-pressing and cold-milling. However, there was no clear pattern in functional property differences and this data will have to be examined in conjunction with other processing data. Examining proteins precipitated at different pH values, the largest fractions of proteins were extracted at pH values of 11 and less than 7. Greater than seventy-six percent of the proteins recovered were precipitated at pH values at or below 7. Functional and thermal property (DSC) analyses were used to show that these protein fractions have lower water absorption and higher melting points. Proteins precipitated at a pH value of 11 had the highest water absorption and lowest melting point. These proteins could be removed relatively easily during processing to decrease the overall water absorption and increase the overall melting point of the final precipitated proteins used in plastics or composites. Water absorption and heat denaturation may cause significant problems for bioplastics and biocomposites.
Publications
- Manamperi, W.A., Chang, K.C., Wiesenborn, D. P., and Pryor, S.W. (2008) Alteration of Osborn Sequence Extraction for Isolation of Canola Proteins. Paper 083924, 2008 ASABE International Meeting, Providence, Rhode Island, Jun 29-Jul 2, 2008.
- Manamperi, W.A., Chang, K.C., and Pryor, S.W. (2008). Thermal and functional properties of canola meal proteins precipitated at different pH values, Paper No. RRV08-803. 2008 CSBE/ASABE North Central Intersectional Conference, Winnipeg, Canada Sept 19-20, 2008.
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