Progress 10/01/01 to 09/30/07
Outputs
WGO is rich in unsaturated fatty acids, policosanol (PC), phytosterols and tocopherols. The majority of these bioactive compounds naturally present in WGO are prone to oxidation and degradation under the conditions used for conventional edible oil extraction and refining methods. Hence, there is a need for development of special techniques to obtain high quality wheat extracts. The objective of this research project was to examine the effect of different extraction methods on the health beneficial wheat components. The effects of temperature (45-135oC at 1500 psi), extraction time, sample size and solvent type on the extraction efficiency and oil quality were studied utilizing pressurized organic solvents. Extraction efficiency of the normal-hexane was compared to that of the iso- and high purity-hexane, iso-propanol, ethanol and acetone. The extracts were analyzed for n-3 and n-6 polyunsaturated fatty acid, tocopherol, tocotrienol and phytosterol contents. Pressurized
solvent extraction method reduced the extraction time significantly as compared to Soxhlet extraction. The amount of extract collected was highest when ethanol was used as a solvent for pressurized solvent extraction. Fatty acid composition of the extracts was not affected by either temperature or extraction method. The experimental results indicate that a pressurized solvent extraction technique reduces solvent consumption and extraction time with no adverse effect on the extraction yield and fatty acid composition of the oil. Supercritical fluid extraction and fractionation technology was also examined as an alternative technique to obtain high quality and purity wheat germ oil. Extraction yields were studied as a function of temperature (40-80oC), pressure (100-550 Bar) and solvent/feed ratio (20-80). The SC-CO2 extracts were analyzed for omega-3 and omega-6 fatty acids, phytosterol, tocopherol and tocotrienol contents. This study indicated that both pressurized solvent and SC-CO2
extraction methods can be utilized to recover wheat germ oil efficiently without adverse effects on the naturally present bioactive components in the oil. The second project involved the assessment of "substantial equivalence" and nutritional safety of biotechnology derived peanut varieties. Ten peanut varieties have been screened for their nutritional composition and flavor profile. TAMRUN01, TX977053, TX977239 and TX977164 are the peanut lines developed from SUNOLEIC and TAMRUN 96 through conventional breeding. OKRUN is the parent peanut variety used for genetic modifications. Chitinase and/or glucanase genes were transferred to OKRUN by the microprojectile bombardment method to develop peanut lines 188, 540 and 654. Oil, protein, ash, moisture, total dietary fiber, mineral, sugar, fatty acid, phytosterol, tocopherol, tocotrienol, and phospholipid composition of all the samples were determined. Experimental results showed that the variations in nutritional composition and flavor
profile of peanut varieties examined in this study were minimal.
Impacts
Wheat is an excellent crop for development of value-added products for functional foods and nutraceutical markets. This study demonstrated that supercritical fluid technology is an environmentally benign method which can be utilized for extraction of health beneficial wheat components and their purification. Products obtained by this technology can be considered as natural because of the lack solvent residues in the product. Currently we are exploring the potential of this technology for commercialization. The implication of our research on genetically modified peanuts is significant, since it shows that peanut cultivars with greater pest and fungal resistance are successfully developed while maintaining their desirable chemical and flavor characteristics. This study is a first step toward generating a resource base for future peanut breeding and genetic engineering programs that focus on development of new peanut lines for the Southwestern region in the US.
Publications
- E.C. Ng, N.T. Dunford, K. Chenault, H. Melouk, J. Damicone. 2007. Flavor attributes of Oklahoma-grown peanuts. Institute of Food Technologists Annual Meeting, Chicago, IL (Abstract).
- N.T. Dunford. 2007. Utilization of Supercritical Fluid Technology for Wheat Germ Oil Processing. American Oil Chemists Society Annual Meeting, Quebec City, Canada (Abstract).
- Ee Chin Ng, Nurhan T. Dunford, and Kelly Chenault. 2007.Flavor Characteristics of Genetically Modified Peanut Varieties. Submitted to Journal of Food Science for publication.
- Ee Chin Ng and Nurhan T. Dunford. 2007.Flavor Profile of Peanut Varieties Developed for Southwestern United States. Submitted to Journal of Agricultural Food Chemistry for publication.
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Progress 10/01/05 to 09/30/06
Outputs
New studies continue to support the growing body of evidence that polyunsaturated fatty acids, specifically omega-3 fatty acids, provide numerous health benefits. Prevention of heart disease, hypertension, Type II diabetes and renal disease and aiding brain development and growth are a few of the many health benefits of omega-3 fatty acids that are reported extensively in the medical literature. Incorporation of omega-3 oils into food products is challenging because of their thermal and oxidative instability which results in deterioration of flavor, increased risk of rancidity and reduced shelf-life. Fish, flax, microalgae and canola oil samples were evaluated for their oxidative and thermal stability in this study. A Thermogravimetric Analyzer (TGA) was used to determine thermal stability of oil samples both under nitrogen and oxygen atmospheres as a function of initial decomposition temperature (Tonset). Activation energy and oil degradation curves for each oil
sample were generated. Oxidative stability of the oil samples was evaluated by using rancimat tests. Correlation equations derived from temperature vs induction time curves were used to describe oxidative stability of each oil. Induction time and Tonset temperature of the oil samples varied depending on the oil source and presence or absence of the antioxidants. Both rancimat and TGA tests showed the same stability trends for the oil samples evaluated in this study (fish and canola were the least and most stable oils, respectively). Natural plant extracts such as oregano and wheat germ oil and grape and coffee extracts were evaluated for their efficacy to improve stability of omega-3 oils. Oregano and wheat germ oil were very effective in increasing the oxidative stability of oils examined in this study. Currently we are working on novel oil encapsulation techniques. Pressurized carbon dioxide, sonication-aided drying and nano-emulsion techniques are being studied to develop
shelf-stable omega-3 oils in emulsions and powder form.
Impacts
Understanding the kinetics and mechanism of thermal degradation and oxidative stability of omega-3 oils is crucial for development of oil stabilization techniques, process control and establishment of standards for food applications. Development of advanced oil stabilization techniques will help to incorporate omega-3 oils in various food products and improve shelf stability of the products. Findings of this study will help the food industry to develop new heart healthy omega-3 oil containing shelf stable products.
Publications
- Beis, S. and Dunford, N.T. 2006. Supercritical Fluid Extraction of Daphne (Laurus nobilis L.) Seed Oil. J. Am. Chem. Soc. 83(11):953-957.
- M. Eisenmenger, N.T. Dunford, F. Eller, S. Taylor, and J. Martinez. 2006. Pilot Scale Supercritical Carbon Dioxide Extraction and Fractionation of Wheat Germ Oil. . J. Am. Chem. Soc. 10(2): 863-868.
- S. Irmak, N. T. Dunford, Stanley E. Gilliland, Veneta Banskalieva and Michael Eisenmenger. 2006. Biocatalysis of Linoleic Acid to Conjugated Linoleic Acid. Lipids 41(8): 771-776.
- Dunford, N.T., Hiziroglu, S. and Holcomb, R. 2006. Effect of Age on the Distribution of Oil in Eastern Redcedar Tree Segments. Bioresource Technology (In Press).
- M. Eisenmenger and N. T. Dunford. 2006. Bioactive Components of Commercial and Supercritical Carbon Dioxide Processed Wheat Germ Oil. Journal of Food Composition and Analysis (Submitted for publication).
- FAPC-135. 2006. Foods, health and omega-3 oils (Facts Sheet) Amogh Ambardekar and Nurhan Turgut Dunford. 2006. Thermal and Oxidative Stability of Omega-3 Oils from Marine and Plant Sources. Abstract and invited oral presentation at the World Conference and Exhibition on Oilseed and Vegetable Oil Utilization: Processing, By-Products, Biodiesel, Specialty and Functional Oils, and New Applications & Technologies in Istanbul, Turkey, 14-16 August 2006. (Abstract)
- Dunford, N.T. 2006. A new trend: omega - 3 fortification of foods (FAPC Flash)
- Dunford, N.T. and Beis, S. 2006. Extraction of Daphne Seed Oil Using Supercritical carbon Dioxide. American Oil Chemists Society Annual Meeting. St. Louis, (Invited oral presentation-Abstract).
- Kenkel, P., Holcomb, R., Dicks, M. and Dunford, N. 2006. Feasibility of a Producer-Owned Winter Canola Processing Venture. Western Agricultural Economics Association Annual Meeting, June 28-30, 2006, Anchorage, Alaska (Abstract).
- R.E. Sievers, B.P. Quinn, J.A. Searles, P. Bhagwat, L.G. Rebits, N.T. Dunford, D. Chen, D. Kristensen, M.T. Hernandez, L. Lindsa, S.P. Cape, C.S. Braun, D.H. McAdams, J.A. Best, J.L. Burger. 2006. Drug Delivery Applications of Particle Technology Using CAN-BD Processing, 2006. Particles 2006. Medical/Biochemical Diagnostic, Pharmaceutical, and Drug Delivery Applications of Particle Technology, 13-16 May 2006, Orlando, Florida.(Abstract)
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Progress 10/01/04 to 09/30/05
Outputs
Wheat germ processing presents challenges due to its high content of polyunsaturated fatty acids and bioactive compounds. These compounds are prone to oxidation and degradation under the conditions used for conventional edible oil extraction and refining methods. Hence there is a need for development of new processing techniques that will maintain wheat germ oil (WGO) quality and biological activity of the oil components during processing. This study examined pilot scale extraction and fractionation of WGO utilizing supercritical CO2 (SC-CO2) as a solvent. The oil fractionation was carried out by using a pilot scale packed column. To best of our knowledge, this is the first study reporting supercritical fluid fractionation (SFF) of WGO in the literature. Chemical composition of WGO products obtained from supercritical fluid (SFE) and SFF processes were compared to those of commercial products. Soybean oil was used as a reference to demonstrate the potential of WGO oil
as a functional food/oil containing a number of bioactive compounds with health benefits. This research study clearly demonstrated that both commercial and SFE WGO were rich in tocopherols and phytosterols and superior to soybean oil. It was also confirmed that nutritional composition of SFE WGO was at least similar (in some cases better) to that of the hexane extracted oil. SFE WGO does not contain phospholipids hence further refining of this product is simplified by elimination of degumming step. Furthermore, SFE WGO can be considered as high purity because of the lack solvent residues in the product. SFE WGO contained significantly higher amount of moisture than that of the hexane extracted oil. Moisture in the SFE WGO can easily be separated in a separator before precipitation of oil from CO2 in a second vessel. This study also illustrated that SFF process was a viable process to remove free fatty acids efficiently from both hexane and SFE extracted WGO while retaining bioactive
oil components in the final product. Wheat is a major commodity throughout the central plains states and with growing interest in nutritional health and functionality of foods, wheat germ may soon become not simply a by-product of wheat milling, but a high value specialty product itself.
Impacts
Our research and development work on environmentally friendly processing techniques and oil/oilseed derived products target disease prevention and improvement of human health. Our research results will benefit oilseed growers, oil/oilseed processing industry and consumers by enhancing nutritional and economic value of oil crops.
Publications
- Irmak, S., and Dunford, N.T. 2005. Policosanol Contents and Compositions of Wheat Varieties. J. Agric. Food Chem. 53(14):5583-5586.
- Irmak, S., Dunford, N.T., and Milligan, J. 2005. Policosanol contents of Beeswax, Sugar Cane and Wheat Extracts. Food Chem. 95:312-318.
- Jonnala, R.S., Dunford, N.T., and Irmak, S. Policosanol, Tocopherol and Phytosterol Composition of Wheat Extracts as Affected by Extraction Methods. Institute of Food Technologists Annual Meeting, New Orleans. 2005.
- Michael Eisenmenger, Nurhan Turgut Dunford, Fred Eller, and Scott Taylor. Pilot Scale Supercritical Carbon Dioxide Extraction and Characterization of Wheat Germ Oil. American Oil Chemists Society Annual Meeting. Salt Lake City, 2005.
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Progress 10/01/03 to 09/30/04
Outputs
Various forms of bran, wheat germ and the clean-out of the screen room are by-products of the wheat milling operations. As these products may represent about 25 percent of the original grain, they are of potentially considerable economic significance to the miller. Wheat germ oil, WGO, has a number of nutritional and health benefits such as reducing blood cholesterol levels, improving physical endurance/fitness and delaying aging. WGO is rich in unsaturated fatty acids, policosanol, PC, phytosterols and tocopherols. The majority of the bioactive compounds naturally present in WGO are prone to oxidation and degradation under the conditions used for conventional edible oil extraction and refining methods. Hence, there is a need for development of special techniques to obtain high quality wheat extracts. The objectives of this research are as follows: 1- determination of PC concentrations in WGO, various wheat fractions and wheat varieties grown in Oklahoma, 2-
examination of the effect of different extraction methods on the chemical composition of wheat extracts, 3- evaluation of supercritical fluid extraction technology as an alternative technique to obtain WGO of high quality and purity, 4- comparison of composition of bioactive components in supercritical carbon dioxide extracted oil to that of the commercial wheat germ oil processed through conventional techniques. Wheat germ, bran and straw samples were extracted by using chloroform, hexane, petroleum ether and ethanol at 80-125 degree Celcius. WGO was extracted by using a pilot scale supercritical carbon dioxide extractor at 80 degree Celcius and 10,000 psi. Wheat germ, bran, shorts, and flour and 31 hard red and white winter wheat varieties grown in Oklahoma were analyzed for their PC content and composition. The solid fraction that precipitated at the bottom of the container containing hexane extracted crude WGO had the high amount of total PC. The PC content of the clear WGO (oil
above the precipitate) was about 17 times smaller than that of the WGO solids/precipitate. Wheat straw contained significantly higher total PC content as compared to that of the other wheat milling fractions. Wheat bran contains a significantly higher amount of PC than the germ. The PC content of Oklahoma grown wheat varieties varied in the range of 3 to 56 mg/kg. Trego (about 56 mg/kg) and Intrada bran (about 37 mg/kg) had the highest PC content among the 31 wheat varieties examined. The organic solvent extraction yields from wheat bran, germ and straw varied between about 1 and 11 perecnt. Wheat straw chloroform extracts contained the highest amount of PC among the samples examined in this study. The yield from supercritical carbon dioxide extraction of wheat germ was about 11 percent, which was very similar to that of conventional hexane extraction process. The findings of this study indicate that WGO and wheat straw may be a source for obtaining PC to be used in dietary
supplements and pharmaceuticals. The experimental results also indicate that supercritical carbon dioxide extraction method can be a viable technique to produce high quality wheat germ oil enriched in bioactive compounds.
Impacts
This research project examines the utilization of plant by-products for value-added product development. Our research and development work on environmentally friendly processing techniques and oil/oilseed derived products target disease prevention and improvement of human health. Our research results will benefit oilseed growers, oil/oilseed processing industry and consumers by enhancing nutritional and economic value of oil crops.
Publications
- Jonnala, R., and Dunford, N.T. 2004. Nutritional Components of Oklahoma Grown Genetically Modified Peanut Varieties. Annual Meeting of the Institute of Food Technologists. Las Vegas, Nevada, July 13-16, 2004.
- Eisenmenger, M., and Dunford, N.T. 2004. Thermal analysis of wheat germ oil. Annual Meeting of the Institute of Food Technologists. Las Vegas, Nevada, July 13-16, 2004.
- Patent: Nurhan Turgut Dunford and Jerry. W. King. 2004. Supercritical Fluid Fractionation Process for Phytosterol Ester Enrichment in Vegetable Oils. U.S. 6,677,469 B1.
- Book: N.T. Dunford and H.B. Dunford (Editors). 2004. Nutritionally Enhanced Oil and Oilseed Processing. AOCS Press, Champaign, IL.
- Book Chapters: Nurhan Turgut Dunford, Jerry, W. King, Gary R. List. 2003. Supercritical Fluid Extraction in Food Engineering. In: Extraction Optimization in Food Engineering. Editors: C. Tzia and G. Liadakis. Chapter 3, page:57-93. Marcel Dekker, Inc., NY.
- Nurhan Turgut Dunford. 2004. Oilseed Based Bioactive Compounds and Their Health Effects. In: Nutritionally Enhanced Oil and Oilseed Processing. Ch.1, pp.1-24. AOCS Press, Champaign, IL. Editors: N.T. Dunford and H.B. Dunford.
- Nurhan Turgut Dunford. 2004. Effects of Oil and Oilseed Processing Techniques on Bioactive Compounds. In: Nutritionally Enhanced Oil and Oilseed Processing. Ch.2, pp. 25-37. AOCS Press, Champaign, IL. Editors: N.T. Dunford and H.B. Dunford.
- Nurhan Turgut Dunford. 2004. Utilization of Supercritical Fluid Technology for Oil and Oilseed Processing. In: Nutritionally Enhanced Oil and Oilseed Processing. Ch. 6, pp. 100-116. AOCS Press, Champaign, IL. Editors: N.T. Dunford and H.B. Dunford.
- Neuman, T. and Dunford, N.T. 2004. Edible Oil Bleaching. In: Nutritionally Enhanced Oil and Oilseed Processing. AOCS Press, Champaign, IL. Editors: N.T. Dunford and H.B. Dunford. Ch.8, pp. 148-160.
- Casilio, D., and Dunford, N.T. 2004. Vacuum Distillation of Edible Oils. In: Nutritionally Enhanced Oil and Oilseed Processing. Ch. 10, pp. 178-192. AOCS Press, Champaign, IL. Editors: N.T. Dunford and H.B. Dunford.
- Abstracts: Dunford, N.T., Milligan, J., and Irmak, S. 2004. Polycosanol Content of Wheat Extracts. AOCS 95th Annual Meeting and Expo, May 9-12 , 2004.
- Dunford, N.T., Milligan, J., and Irmak, S. 2004. Polycosanols as Nutraceuticals. 1st International Congress on Functional Foods and Nutraceuticals. 27-29 April, 2004. Aksu/Antalya/Turkey.
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Progress 10/01/02 to 09/30/03
Outputs
One of the objectives of this research program is the assessment of substantial equivalence and nutritional safety of biotechnology derived peanut varieties. This year 10 peanut varieties have been screened for their nutritional composition. TAMRUN01, TX977053, TX977239 and TX977164 are the peanut lines developed from SUNOLEIC and TAMRUN 96 through conventional breeding. OKRUN is the parent peanut variety used for genetic modifications. Chitinase and/or glucanase genes were transferred to OKRUN by the microprojectile bombardment method to develop peanut lines 188, 540 and 654. Oil, protein, ash, moisture, total dietary fiber, mineral and fatty acid composition of all the samples were determined. The experimental results indicate no major changes in the composition of peanut lines examined in this study. Currently phytosterol, tocopherol, tocotrienol, and phospholipid composition of the samples are being determined. Allergenic components, Ara h I and Ara h II, of
peanut samples will also be determined. This research program also examines the development of value-added products from wheat milling industry byproducts, specifically from wheat germ oil. Wheat germ oil has been reported to improve human physical fitness and this effect is attributed to its high policosanol content. Currently a number of dietary supplements containing policosanol are commercially available in the US market. The majority of these products are prepared from beeswax or sugar cane extracts. Although wheat germ oil contains policosanol, to our knowledge there is no commercial product containing wheat policosanol. The main objective of this study is to compare the policosanol content and composition of beeswax, sugar cane and wheat. Wheat samples grown in Oklahoma (30 hard red and white winter wheat varieties) were fractionated into bran and flour. A gas chromatography-mass spectroscopy method was developed to quantify policosanol content of the fractions obtained from
different wheat varieties. Policosanol content and composition of the wheat samples were compared to that of the beeswax, sugarcane and commercial policosanol containing dietary supplements.
Impacts
This research project examines the utilization of plant by-products for value-added product development. Our research and development work on environmentally friendly processing techniques and oil/oilseed derived products target disease prevention and improvement of human health. Our research results will benefit oilseed growers, oil/oilseed processing industry and consumers by enhancing nutritional and economic value of oil crops.
Publications
- Dunford, N.T., Teel, J.A., King, J.W. 2003. A Continuous Countercurrent Supercritical Fluid Fractionation Process for Phytosterol Ester Fortification in Vegetable oils. Food Research International. 36(2):175 - 181. Dunford, N.T. and Zhang, M. 2003. Pressurized Solvent Extraction of Wheat Germ Oil. Food Research International. 36:905-909. Dunford, N.T. and Martinez, J.L. 2003. Nutritional Composition of Supercritical Carbon Dioxide Extracted Wheat Germ Oil. Vol. 1, Page: 273-278. Proceedings of 6th International Symposium on Supercritical Fluids, April 28-30, 2003, Versailles, France.
- Dunford, N.T. and Martinez, J.L. Nutritional Composition of Supercritical Carbon Dioxide Extracted Wheat Germ Oil. 6th International Symposium on Supercritical Fluids, April 28-30, 2003, Versailles, France. Dunford, N.T. Bioactive components of peanuts. Annual Meeting of the Institute of Food Technologists. Chicago, IL, July 12-16, 2003.
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Progress 10/01/01 to 09/30/02
Outputs
Extraction of wheat germ oil utilizing pressurized solvents and supercritical carbon dioxide was examined. The effects of temperature (45-135oC at 1500 psi), extraction time, sample size and solvent type on the extraction efficiency and oil quality were studied utilizing pressurized organic solvents. Extraction efficiency of the normal-hexane was compared to that of the iso- and high purity-hexane, iso-propanol, ethanol and acetone. The extracts were analyzed for n-3 and n-6 polyunsaturated fatty acid, tocopherol, tocotrienol and phytosterol content. Pressurized solvent extraction method reduced the extraction time significantly as compared to Soxhlet extraction. The time required for complete recovery of oil from wheat germ was depended on the amount of feed. The amount of extract collected was highest when ethanol was used as a solvent for pressurized solvent extraction. Extraction efficiency of pressurized solvent extracted oil was similar to that of Soxhlet
extract. Fatty acid composition of the extracts was not affected by either temperature or extraction method. The experimental results indicate that a pressurized solvent extraction technique reduces solvent consumption and extraction time with no adverse effect on the extraction yield and fatty acid composition of the oil. Supercritical fluid extraction technology was also examined as an alternative technique to obtain high quality and purity wheat germ oil. Extraction yields were examined as a function of temperature (40-80oC), pressure (100-550 Bar) and solvent/feed ratio (20-80). The effects of SC-CO2 extraction conditions on omega-3 and omega-6 fatty acids, phytosterol, tocopherol and tocotrienol content of the wheat germ oil were examined. Fatty acid composition of the wheat germ extracts was similar for all three extraction methods studied. This study indicated that both pressurized solvent and SC-CO2 extraction methods can be utilized to recover wheat germ oil efficiently
without adverse effects on the naturally present bioactive components in the oil. Bioactive components of other oils such as peanut and oregano oil are being also studied. Next phase of this project will be fractionation of wheat germ oil utilizing supercritical fluid fractionation and molecular distillation techniques. Bioactive compounds naturally present in crude wheat germ oil will be enhanced during the fractionation and refining process.
Impacts
This research project examines the utilization of plant by-products for value-added product development. Our research and development work on environmentally friendly processing techniques and oil/oilseed derived products target disease prevention and improvement of human health. Our research results will benefit oilseed growers, oil/oilseed processing industry and consumer by enhancing nutritional and economic value of oil crops.
Publications
- Dunford, N.T. and Zhang, M. 2002. Pressurized Solvent Extraction of Wheat Germ Oil. Food Research International (Manuscript submitted for publication).
- Dunford, N.T. 2002. Pressurized Solvent Extraction of Wheat Germ Oil. 93ndAOCS Annual Meeting & Expo. May 5-8, 2002, Montreal, Canada (Abstract).
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