Progress 10/01/03 to 09/30/09
Outputs
OUTPUTS: Experiments are being conducted and data is being analyzed related to the optimization of human health through creating an optimal, nutritious diet guarding against oxidative stress in humans and protecting against oxidation in food, thereby enhancing food product stability (particularly lipid stability) and ultimately quality. Oilseed quality is being examined by storage stability and compositional studies, investigating antioxidant components and how they are impacted by growth of soybean plants in conditions of elevated ozone and carbon dioxide. This information will reveal the impact of altered environments on potential bioactive components of soybean oil and meal as well as information related to the impact of these conditions on soybean plant stress and oxidative stability of crude soybean oil. Also, we are investigation soybean cultivar differences in response to altered environments, including low phytate plants. We are determining the potential role of phytate as an antioxidant in soybeans. Many of these data were presented at the Annual Meeting of the Institute of Food Technologists (Summer, 2009). We have investigated the use of irradiation processing on papaya nutrients and flavor in the development of a high quality, high nutritional value papaya beverage. We utilized Electron Spin Resonance in the evaluation of irradiation processing of papaya to determine the extent of free radical damage and antioxidant protection. We combined this papaya work with examination of the synergistic effects of antioxidants from various natural sources (fruit and honey). This was accepted for publication in Journal of Agricultural and Food Chemistry. We have also begun the investigation of the potential health benefits from papaya, including digestive enzymes and fiber. One MS student working on this project went to Ecuador over the summer to expand some of this work to exotic "super fruits" and to build collaborative research. She was supported by a UIUC Tinker Fellowship for this work. We have also continued sensory studies on aroma of fresh vs irradiated papaya nectar and this will be complemented by flavor chemistry currently underway. Some of this work has also recently been submitted as an abstract to be presented at the Annual Meeting of the Institute of Food Technologists (Summer, 2010). PARTICIPANTS: Nicki J. Engeseth, Ph.D., Associate Professor, University of Illinois. Project Director, coordination of project and submission of manuscripts. Crystal Goshorn, M.S., Graduate Student, performing experiments on the impact of elevated carbon dioxide and ozone on composition and stability of soybeans and their oils. Tory Parker, M.S., Graduate Student, performing experiments on the impact of processing on the quality of papaya. Juan E. Andrade, Ph.D., collaborator, assisting with conducting tocopherol analyses of soybean samples. Monica Garces, M.S., Graduate Student, performing experiments on the digestive properties and health benefits of papaya. Yanhua He, Graduate Student, performing experiments on flavor changes in papaya with irradiation. TARGET AUDIENCES: Much of the oilseed information will be helpful to the soybean industry and growers. Additionally it will be of major importance to scientists studying the impact of altered atmospheric gas concentrations on plant life and food production. Oil stability studies will be of importance in selection of soybean cultivars and will be of great interest to nutritionists and food scientists in terms of the deciphering of the role of phytate as an antioxidant in soybeans. Our antioxidant/papaya research will be of major importance to the public in terms of demonstrating the human health benefits of different types of food processing - this is also of benefit to the fruit and vegetable industry. Also, we reveal the benefits of irradiation in processing of papaya. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Our oilseed research has focused on responses of soybeans to growth under elevated ozone and carbon dioxide. We have found that soybean composition of soybeans is greatly impacted by growing conditions. Oil quality and antioxidant components are also impacted. Phytate concentrations were not affected by atmospheric gas concentrations. Tocopherol profiles were not altered greatly by atmospheric gas concentrations. Oils from soybeans grown under either elevated ozone or elevated carbon dioxide experienced a higher degree of oxidative stability compared to oil from control/ambient conditions. Oil from soybeans grown under combined elevated carbon dioxide and ozone had increased oxidative stability, observed primarily at longer storage times. Freeze drying soybeans before oil extraction had a dramatic impact on oil stability, increasing the peroxide value as much as tenfold. This study suggests that oils extracted from soybeans grown at predicted atmospheric concentrations of carbon dioxide and ozone may be protected against oxidation. Isoflavone and total phenolic analyses are also underway. Fully ripened papaya fruit (Carica papaya L.) was pulped, diluted, and processed with irradiation (5 kGy) or a combination of irradiation (5 kGy) and mild heat (80 C, 5 min). Volatile components were profiled and sensory analysis completed. Informal testing upon product development indicated irradiation increased sweetness perception of the nectars. Sugar analysis confirmed the hypothesis that there was no difference in sugar composition with processing. Aroma analysis indicated significantly higher consumer acceptance for control samples over irradiated, both with aroma and overall appearance; however, mean scores ranged from 4.04-6.84 on a 9-point scale, only one mean below the neutral (4.50) in terms of liking or disliking. Flavor analysis of neutral/basic and acidic fractions revealed at least 100 compounds. Among the components identified, esters and analyzed were further researched for their role in sweetness perception of the nectars.
Publications
- Goshorn, C.D., Andrade, J.E. and Engeseth, N.J. 2009. The effect of atmospheric growing conditions on the oxidative stability of crude soybean oil. Presented at the Annual Meeting of the Institute of Food Technologists, Annaheim, CA, June, 2009.
- Garces, M., Moy, M., Van Haren, K., He, Y., Azizi, I. and Engeseth, N.J. 2009. Proteolytic enzyme activity of papaya fruit. Presented at the Annual Meeting of the Institute of Food Technologists, Annaheim, CA, June, 2009.
- Parker, T.L., Miller, S.A., Meyers, L.A., Miguez, F.E. and Engeseth, N.J. 2009. Evaluation of synergistic antioxidant potential of complex mixtures using Oxygen Radical Absorbance Capacity (ORAC) and Electron Paramagnetic Resonance (EPR). J. Agric. Food Chem. [Online Submission].
- He, Y., Garces, M., Toshkov, S., Parker, T., Jackson, M., Kim, Cadwallader, K. and Engeseth, N.J. 2010. Impact of irradiation processing on papaya nectar flavor. Abstract submitted for presentation at the Annual Meeting of the Institute of Food Technologists, Chicago, IL, July 2010.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Experiments are being conducted and data is being analyzed related to the optimization of human health through creating an optimal, nutritious diet guarding against oxidative stress in humans and protecting against oxidation in food, thereby enhancing food product stability (particularly lipid stability) and ultimately quality. Oilseed quality is being examined by storage stability and compositional studies, and by investigating antioxidant components and how they are impacted by growth of soybean plants in conditions of elevated ozone and carbon dioxide. This information will reveal the impact of altered environments on potential bioactive components of soybean oil and meal as well as information related to the impact of these conditions on soybean plant stress and oxidative stability of crude soybean oil. Also, we are investigation soybean cultivar differences in response to altered environments, including low phytate plants. We are determining the potential role of phytate as an antioxidant in soybeans. Many of these data were recently submitted as an abstract to be presented at the Annual Meeting of the Institute of Food Technologists (Summer, 2009). We have investigated the use of irradiation processing on papaya nutrients and flavor in the development of a high quality, high nutritional value papaya beverage. We have begun the investigation of Electron Spin Resonance in the evaluation of irradiation processing of papaya to determine the extent of free radical damage and antioxidant protection. We have also begun the investigation of the potential health benefits from papaya, including digestive enzymes and fiber. Some of this work has also recently been submitted as an abstract to be presented at the Annual Meeting of the Institute of Food Technologists (Summer, 2009). PARTICIPANTS: Nicki J. Engeseth, Ph.D., Associate Professor, University of Illinois. Project Director, coordination of project and submission of manuscripts. Crystal Goshorn, M.S., Graduate Student, performing experiments on the impact of elevated carbon dioxide and ozone on composition and stability of soybeans and their oils. Tory Parker, M.S., Graduate Student, performing experiments on the impact of processing on the quality of papaya. Juan E. Andrade, Ph.D., collaborator, assisting with conducting tocopherol analyses of soybean samples. Monica Garces, M.S., Graduate Student, performing experiments on the digestive properties and health benefits of papaya. TARGET AUDIENCES: Much of the oilseed information will be helpful to the soybean industry and growers. Additionally, it will be of major importance to scientists studying the impact of altered atmospheric gas concentrations on plant life and food production. Oil stability studies will be of importance in selection of soybean cultivars and will be of great interest to nutritionists and food scientists in terms of the deciphering of the role of phytate as an antioxidant in soybeans. Our antioxidant/papaya research will be of major importance to the public in terms of demonstrating the human health benefits of different types of food processing - this is also of benefit to the fruit and vegetable industry. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Our oilseed research has focused on responses of soybeans to growth under elevated ozone and carbon dioxide. We have found that soybean composition of soybeans is greatly impacted by growing conditions. Oil quality and antioxidant components are also impacted. Phytate concentrations were not affected by atmospheric gas concentrations. Tocopherol profiles were not altered greatly by atmospheric gas concentrations. Oils from soybeans grown under either elevated ozone or elevated carbon dioxide experienced a higher degree of oxidative stability compared to oil from control/ambient conditions. Oil from soybeans grown under combined elevated carbon dioxide and ozone had increased oxidative stability, observed primarily at longer storage times. Freeze drying soybeans before oil extraction had a dramatic impact on oil stability, increasing the peroxide value as much as tenfold. This study suggests that oils extracted from soybeans grown at predicted atmospheric concentrations of carbon dioxide and ozone may be protected against oxidation. Other chemical components are being investigated to determine their role in this protection. Papaya fruit is often noted for its beneficial impact on digestion. Proteolytic enzymatic action is often cited as the main reason for this attribute. However, it is also commonly stated that papain is only active in unripe fruit. The literature is lacking in evidence of full characterization of the activity of papain in papaya fruit development. The objective of this study was to characterize proteolytic activity in papaya and evaluate its potential to serve as a digestive aid. There is significant measurable papain proteolytic activity in the pulp of fresh papaya fruit. Enzymatic protease activity stability studies also indicated a 25-40% reduction in enzymatic activity after six weeks storage at -20C.
Publications
- Parker, T.L., Esgro, S.T., Miller, S.A., Myers, L.E., Meister, R.A. and Engeseth, N.J. 2009. Development of a nutritionally and organoleptically optimized papaya pulp nectar using a combination of mild heat and irradiation. To be presented at the Annual Meeting of the Institute of Food Technologists, New Orleans, LA in June of 2009.
- Rasmussen, C.N., Wang, X.-H., Leung, S., Andrae, L.M., Schmidt, S.J. and Engeseth, N.J. 2008. Selection and use of honey as an antioxidant in a French salad dressing system. J. Agric. Food Chem. 56:8650-8657.
- Goshorn, C.D., Andrade, J.E. and Engeseth, N.J. 2009. The effect of atmospheric growing conditions on the oxidative stability of crude soybean oil. Submitted for presentation at the Annual Meeting of the Institute of Food Technologists, Annaheim, CA in June of 2009.
- Garces, M., Moy, M., Van Haren, K., He, Y., Azizi, I. and Engeseth, N.J. 2009. Proteolytic enzyme activity of papaya fruit. Submitted for presentation at the Annual Meeting of the Institute of Food Technologists, Annaheim, CA, June, 2009.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Experiments are being conducted and data is being analyzed related to the optimization of human health through creating an optimal, nutritious diet guarding against oxidative stress in humans and protecting against oxidation in food, thereby enhancing food product stability (particularly lipid stability) and ultimately quality. Oilseed quality is being examined by storage stability and compositional studies and will be a great way to determine the impact of elevated carbon dioxide and ozone on food lipids and oxidative stress to soybean plants and products. We have investigated impact of high ozone and carbon dioxide on tocopherol composition, phytate concentration and oxidative stability of crude soybean oils. Many of these data were recently submitted as an abstract to be presented at the Annual Meeting of the Institute of Food Technologists (Summer, 2008). Natural antioxidant studies continue with papaya. We have generated a high quality, high nutritional value papaya
beverage using irradiation processing and have presented this to the Hawaiian Papaya Industry Association (Sept, 2007). We are moving to further characterizations of this product and its processing with the goal of enhancing uses for papaya fruit. Our grape/raisin research on processing impact on antioxidants and use as a dietary source of antioxidants has recently been published.
PARTICIPANTS: Nicki J. Engeseth, Ph.D., Associate Professor, University of Illinois. Project Director, coordination of project and submission of manuscripts. Crystal Goshorn, M.S., Graduate Student, performing experiments on the impact of elevated carbon dioxide and ozone on composition and stability of soybeans and their oils. Tory Parker, M.S., Graduate Student, performing experiments on the impact of processing on the quality of papaya. Juan E. Andrade, Ph.D., collaborator, assisting with conducting tocopherol analyses of soybean samples.
TARGET AUDIENCES: Much of the oilseed information will be helpful to the soybean industry and growers. Additionally it will be of major importance to scientists studying the impact of altered atmospheric gas concentrations on plant life and food production. Oil stability studies will be of importance in selection of soybean cultivars and will be of great interest to nutritionists and food scientists in terms of the deciphering of the role of phytate as an antioxidant in soybeans. Our antioxidant research will be of major importance to the public in terms of demonstrating the human health benefits of different types of food processing - this is also of benefit to the fruit and vegetable industry.
Impacts
Our oilseed research has focused on responses of soybeans to growth under elevated ozone and carbon dioxide. We have found that composition of soybeans is greatly impacted by growing conditions and now are extending this to product quality (such as oil stability). We have determined that at least in some cultivars of soybeans, the oil stability is impacted by the original growing atmospheric conditions. We are further deciphering the role of composition of tocopherols, isoflavones and phytate (all natural antioxidants) in this stabilization. Our papaya research has demonstrated that irradiation enhances the sweetness and flavor of a pulp-based papaya beverage. Irradiation has also been effective as a microbial inhibitor in this system. Additionally, nutrient content of the papaya is maintained fairly well with minimal heat processing and irradiation.
Publications
- Parker, T., Wang, W.H. and Engeseth, N.J. 2007. Antioxidant capacity and phenolic content of Thompson seedless grapes, sun-dried raisins and golden raisins and their effects on serum antioxidant capacity in healthy human males. Presented at the Annual Meeting of the Institute of Food Technologists, Chicago, IL July, 2007.
- Goshorn, C.D., Andrade, J.E. and Engeseth, N.J. 2008. The effect of growing conditions on the oxidative stability of crude soybean oil. Submitted for presentation at the Annual Meeting of the Institute of Food Technologists, New Orleans, LA, June, 2008.
- Parker, T.L., Wang, X.-H., Pazmino, J. and Engeseth, N.J. 2007. Antioxidant capacity and phenolic content of grapes, sun-dried raisins and golden raisins and their effect on ex vivo serum antioxidant capacity. J. Agric. Food Chem. 55:8472-8477.
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Progress 01/01/06 to 12/31/06
Outputs
Our work with the SOYFACE project has made significant progress into the investigation of soybean quality as a result of growth in elevated carbon dioxide and ozone. We have a particular emphasis on the impact on lipids and on health related components, i.e., minerals and antioxidants. Our research has demonstrated that elevated CO2 results in a decrease in certain key minerals, namely calcium and zinc. These minerals are essential to the plant physiology as well as to human health. Our current research to follow up on the mineral findings is related to the ability of phytate to serve as an antioxidant in soybean seeds. We are studying the potential for phytate to serve as an antioxidant in soybean seeds (as believed) and are investigating the impact of environment on low vs normal phytate soybeans. Oxidative stability studies and radical formation analyses have begun. We are in the process of preparing three manuscripts for publication on the compositional studies of
soybean with altered atmospheric conditions. We completed a human feeding trial with grapes and raisins to investigate the impact of consumption on reduction of oxidative stress. We have also generated the first comprehensive report of the ORAC (oxygen radical absorbance capacity) antioxidant capacity and phenolic composition of changes that occur in processing grapes into raisins. This research is currently being submitted for publication. We have continued our antioxidant research in the area of preparing a papaya-based fruit juice that is shelf stable using novel processing. The papaya fruit is one of the most beneficial fruits in terms of human nutrition due to its high content of vitamin C, carotenoids, potassium and folate. However, papaya fruit is not shelf stable and is thus limited in its distribution. We are working towards a shelf stable pulp-based papaya juice product that maintains the nutrients and flavor of fresh papaya. Thus the ability to deliver economically this
highly nutritious fruit to consumers worldwide would be possible. We are investigating the use of irradiation for processing to use minimal heat and preserve quality. Our research thus far indicates sweeter juice and softer pulp in papaya juice upon irradiation. Also, in line with this application we are investigating radical generation in irradiation of the juice product using electron spin resonance (ESR). This technique is very powerful, yet has only received minimal application to foods. We intend to extend this technique to many of our projects related to food lipid quality and human health. We also continue to research the chemistry of chocolate and the impact of storage on chocolate quality. Due to its long shelf life, chocolate often undergoes bloom formation due to improper storage and handling. Our laboratory is studying the impact of these changes in chocolate lipids on flavor and texture as well as antioxidant capacity. An educational component of this research will soon
also be incorporated to our research program.
Impacts
Our work with elevated carbon dioxide and ozone is demonstrating previously unreported impacts on quality of soybeans. Minerals and phytate analyses will be necessary to understanding the impact of potential future atmospheric conditions on plants. Our research on grapes and raisins will draw attention to the impact of human consumption of raisins and the important contributions of the antioxidant components and will complement the literature which is lacking in phenolic and ORAC analysis of raisins. We anticipate great enhancement of worldwide exposure to and acceptance of the highly nutritious papaya fruit. Chocolate quality is becoming an important issue due to the increased emphasis on chocolate phenolics and human health. Changes in lipid structural components of chocolate that impact human health and food quality are of significant concern.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
Our work with the SOYFACE project has made significant progress into the investigation of soybean quality as a result of growth in elevated carbon dioxide and ozone. We have a particular emphasis on the impact on lipids and on health related components, i.e., minerals and antioxidants. Our research has demonstrated that elevated CO2 results in a decrease in certain key minerals, namely calcium and zinc. These minerals are essential to the plant physiology as well as to human health. Due to associations of these minerals with germination and quality as well as specific enzymes, particularly superoxide dismutase, it is expected that the change in mineral composition may dramatically affect lipid stability and human health. We are also investigating changes in phenolics, such as isoflavones, that have potential antioxidant capabilities. Oxidative stability studies of soybean oil and meal are in progress. We are continuing our ACP research into the impact of alteration of
ACP isoforms on composition and content of oils in Arabidopsis thaliana plants. Leaf major isoform alterations in Arabidopsis seed are currently being studied. Our experiments investigating the substation of honey for high fructose corn syrup and EDTA (a synthetic antioxidant) in salad oils is complete and being written for publication. Blueberry honey was quite effective at reducing oxidation over a one year storage period and could be a great replacement for the sweetener and EDTA in salad dressing emulsion systems. Also, we have published our work on the antioxidant properties of honey wine (mead). We completed a human feeding trial with grapes and raisins to investigate the impact of consumption on reduction of oxidative stress. We have also generated the first comprehensive report of the ORAC (oxygen radical absorbance capacity) antioxidant capacity and phenolic composition of changes that occur in processing grapes into raisins. This research is currently being compiled into a
manuscript.
Impacts
Our work with elevated carbon dioxide and ozone is demonstrating previously unreported impacts on quality of soybeans. Our mineral work will be the first report of such a study and is already gaining much attention through our presentation at meetings. This should be a significant insight into nutritional and plant physiological implications of future atmospheric conditions affecting plants. Our work on honey as a source of natural antioxidants is popular in light of the emphasis away from high fructose corn syrup and also from synthetic chemical additives, such as EDTA. Honey performed much better than anticipated initially in stabilization of salad dressing formulations. This should be helpful to the food industry. Our grape and raisin research is expected to reveal important information regarding bioavailability of such antioxidants and their ability to protect against oxidative stress.
Publications
- Wintersteen, C.L., Andrae, L.M. and Engeseth, N.J. 2005. Effect of heat treatment on antioxidant capacity and flavor volatiles of mead. J. Food Sci. 70(2)119-126.
- Roegge, C.S., Widholm, J.J., Engeseth, N.J., Wang, X.-H., Brosch, K.O., Seegal, R.F. and Schantz, S.L. 2005. Delayed spatial alterntion impairments in adult rats following dietary n-6 deficiency during development. Neurotoxicology and Teratology 27:485-495.
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Progress 01/01/04 to 12/31/04
Outputs
In collaboration with Dr. Jack Widholm's laboratory (UIUC) we are in the process of genetically manipulating ACP levels in soybean plants. Soybean embryos experienced a decrease in lipid content in response to antisense inhibition of expression of ACP; these studies are now being confirmed and are being extended into generation of full soybean plants. We have made significant progress in analysis of soybean seed for alteration in lipid content as a result of growth in elevated carbon dioxide and/or ozone. We are investigating these hypotheses: 1) seeds from plants grown under high carbon dioxide would increase in lipid content, 2) high concentrations of ozone would reduce total lipid, and 3) under combined elevated carbon dioxide and ozone, CO2 would attenuate the negative effect of high O3. Alterations in total lipid in response to changes in atmospheric composition was not uniform amongst cultivars. Certain cultivars did not experience differences in total lipid
with treatment. Others experienced increased lipids under high CO2 and others decreased lipid in high O3. We have begun analysis of emulsion-based salad dressings containing honey as a potential replacement for both sweetener (high fructose corn syrup) and for EDTA (a synthetic antioxidant used to stabilize the oils). Blueberry honey was very effective after three months storage at protection against oxidation of oil in french dressing formulations. This may prove to be a strong application of honey for the food industry. We have also begun to analyze the antioxidant capacity and phenolic distribution in grapes and raisins that are processed from these grapes. We are in the process of working out all the details for a human raisin/grape feeding study to begin this spring.
Impacts
The basic work on ACP has resulted in the collection of much information about the specific roles of ACP isoforms in plant fatty acid and lipid biosynthesis. Now extension of this into crop plants of economic importance should reveal valuable information that may be useful to the optimization of soybean plants. We have also focused on optimization of soybean plants through a detailed study of what changes in lipids occur during growth under atmospheric conditions of elevated ozone and carbon dioxide. There is great potential to increase lipid content in select soybean cultivars under future atmospheric conditions; other cultivars may not be viable. More research should be conducted to obtain a better understanding of the mechanism for regulating lipid deposition under high CO2 and O3 and to what extent it can be controlled. Our laboratory has significantly advanced the scientific basis for using honey as a healthy food/ingredient. We have extended this into salad
dressing applications, demonstrating a beneficial application of this food ingredient to the food industry. Our grape and raisin research is expected to reveal important information regarding bioavailability of such antioxidants and their ability to protect against oxidative stress.
Publications
- Wang, X.-H., Gheldof, N. and Engeseth, N.J. 2004. Effect of processing and storage on antioxidant capacity of honey. J. Food Sci. 69(2):96-101.
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Progress 01/01/03 to 12/31/03
Outputs
Arabidopsis plants were genetically manipulated to alter expression of different isoforms of Acyl Carrier Protein. Several lines of plants have been generated. One set of plants we studied was designed to reduce expression of the major ACP isoform in leaf (ACP-4). There was a dramatic reduction in ACP-4 and reduction of leaf lipid content (22-60%) based on fresh leaf weight. Additionally, there were varying degrees of bleaching of the plants and reduced photosynthetic efficiency. Also, fatty acid composition was affected. Results suggested that ACP-4 plays a major role in synthesis of fatty acids for chloroplast membrane development. Also, lipid changes have revealed key information about the flow of fatty acids in the metabolic pathways. This work has been published (Branen et al., 2003). We have additional Arabidopsis plants generated from manipulation (decrease expression) of two other isoforms of ACP (ACP-1 and ACP-2), with direction of the changes specifically to
the seed. Lipid content was reduced 5-40% without affecting fatty acid composition. We anticipated alterations in carbohydrate and protein in response to reduced lipid accumulation in seeds. However, starch and protein was not significantly affected. Seeds were lower in weight; this is the subject of future research. We have also extended these informative studies into soybean plants. Dramatic reductions in oil content may be achieved through manipulation of ACP levels; this may be used to decrease oil content of agronomically important crops. Also, this may be achieved without major adverse effects on other storage components. We have conducted significant amounts of research to demonstrate the potential of honey as a source of antioxidants to protect foods from oxidative deterioration and thus protect consumers from the damaging effects of consumption of oxidized food lipids. This has included the demonstration that honey provides protection against oxidative stress in humans. After
consumption of honey in water the antioxidant capacity of blood was increased (Gheldof et al., 2003). We also demonstrated that processing of honey has an impact on the antioxidant capacity and that this impact varies greatly with honeys from different floral sources (Wang et al., accepted for publication). Even though the processing reduced antioxidant capacity of certain honeys, the levels of antioxidant capacity observed were still significant in terms of being able to provide protection against oxidative reactions that have been tested previously in our laboratory. We have also begun the formulation of salad dressings incorporating honey as a source of antioxidants to replace the synthetic antioxidants normally used, such as EDTA. We have screened several honey floral sources and selected four that would be most likely to serve as powerful antioxidants based on antioxidant capacity and phenolic composition. This is the subject of our submitted abstract to the Institute of Food
Technologists meeting next July.
Impacts
This basic work on ACP has resulted in the collection of much information about the specific roles of ACP isoforms in plant fatty acid and lipid biosynthesis. Our work has dramatically impacted plant research by demonstrating the impact of various ACP isoforms in terms of function and regulation. ACP is proving to be an effective tool for manipulation of lipids in plants. This could greatly impact genetic engineering efforts for creating new plant oils. Our laboratory has significantly advanced the scientific basis for using honey as a healthy food/ingredient. This has received enormous attention from industry and consumers. Honey as a source of antioxidants has demonstrated effectiveness at preventing food lipid oxidation (a major food deterioration problem) and as a potential dietary antioxidant to enhance human health. This will be of benefit to consumers and to the food industry.
Publications
- Branen, J.K., Shintani, D.K. and Engeseth, N.J. 2003. Expression of antisense acyl carrier protein-4 (LMI-ACP) reduces lipid content in Arabidopsis leaf tissue. Plant Phys. 132:748-756.
- Branen, J., Kwon, M. and Engeseth, N.J. 2003. Expression of antisense acyl carrier protein-4 (LMI-ACP) reduces lipid content in Arabidopsis leaf tissue. In: Advanced Research on Plant Lipids. Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 73-76.
- Gheldof, N., Wang, X. and Engeseth, N.J. 2003. Buckwheat honey increases serum antioxidant capacity in humans. Journal of Agricultural and Food Chemistry. 51:1500-1505.
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Progress 01/01/02 to 12/31/02
Outputs
The major objective of this proposal is to study chemical reactions and biosynthetic pathways involving food lipids and antioxidants to improve food quality and human health. Specific aim #1 was to alter oilseed storage reserves (lipid, carbohydrate, and protein) by genetic manipulation. We have generated several sets of transgenic Arabidopsis plants containing constructs designed to alter expression of different acyl carrier protein (ACP; a key cofactor in plant fatty acid synthesis) isoforms. We were first to demonstrate in vivo that ACP isoforms play a role in determining plant fatty acid composition (Branen et al., 2001). Antisense expression of ACP-2 and ACP-1 in seed tissue resulted in two more sets of transgenic plants. We achieved 5-30% reduction of oil content in these plants. Protein and carbohydrate were not dramatically altered; however, seed weight was dramatically reduced. Another dramatic alteration observed was a decrease in leaf lipids when the major
ACP isoform of leaf was decreased by antisense technology. This resulted in poor plant physiology, bleached leaves, stunted growth, and reduced levels of 16:3 in the chloroplast membrane lipid MGDG. Results were presented at the International Plant Lipid Conference in Japan, May, 2002 and the leaf major isoform results have recently been accepted for publication in Plant Physiology. Specific aim #2 was to evaluate the antioxidant effectiveness of honey. We demonstrated the effectiveness of honey as an inhibitor of oxidation in certain food systems (Chen et al., 2000; McKibben et al., 2002) and extended this research into nutritional applications. Thorough characterization of the antioxidant components of seven floral sources of honey was conducted (Gheldof et al., 2002). Phenolics correlated highly with antioxidant capacity, but were not solely responsible. Then, these honeys prevented copper catalyzed lipid oxidation in human blood serum in vitro. Additionally, the ORAC assay was
applied to these honeys as a measure of antioxidant capacity to determine that on a fresh weight basis, honey has a similar antioxidant capacity to many fruits and vegetables (Gheldof and Engeseth, 2002). We conducted a human feeding trial of 5 beverages: water, water + honey, black tea, honey + black tea, or black tea + sugar analogue. Male subjects (18-68 years) were fed 500 ml of each of these beverages and serum antioxidant capacity was measured at specific time points after consumption. Honey + water significantly increased the antioxidant capacity of blood (Gheldof et al., 2003). Studies on the impact of processing of honey on antioxidant capacity are being completed and will soon be submitted for publication. We also conducted a study on the antimutagenic effect of honey in the Ames assay against a commonly encountered food mutagen. Honey was shown to be antimutagenic, but the sugar analogue to honey was also demonstrated antimutagenic. Long-term studies of the impact of honey
consumption are underway.
Impacts
Much information will be obtained about the specific roles of ACP isoforms in plant fatty acid and lipid biosynthesis from this work. We will also be able to gather important information about carbon partitioning in oilseeds. Our work has dramatically impacted ACP knowledge by demonstrating the impact of various ACP isoforms in terms of function and regulation. ACP is proving to be a quite effective tool for manipulation of lipids in plants. This could greatly impact genetic engineering efforts in plant oils. Our honey work has demonstrated effectiveness of honey as a source of antioxidants both in food systems and potentially for human health. Honey antioxidant characterization will allow selection of honeys for various applications and a better understanding of what actually provides antioxidant action to honey. This should be beneficial to the food industry. Also, our work in human systems provides evidence that honey is not mutagenic and may act against commonly
encountered food mutagens and thus may enhance food products more than just by prevention of oxidation. Our research has thus demonstrated that honey has great potential for enhancing the food supply by protection against deterioration reactions in foods and to serve as a source of dietary antioxidants. Although honey is not consumed in as large a quantity as fruits and vegetables our work demonstrates that it may very well be worth substitution of honey for a fair amount of the "empty" calories typically consumed as sugar.
Publications
- Mckibben, J. and Engeseth, N.J. 2002. Honey as a protective agent against lipid oxidation in ground turkey. Journal of Agricultural and Food Chemistry. 50(3):592-595.
- Gheldof, N., Wang, X. and Engeseth, N.J. 2002. Identification and quantification of antioxidant components of honeys from various floral sources. Journal of Agricultural and Food Chemistry. 50(21):5870-5877.
- Wang, X.-H., Andrae, L. and Engeseth, N.J. 2002. Antimutagenic effect of honeys from different floral sources against Trp-p-1. Journal of Agricultural and Food Chemistry. 50(23):6923-6928.
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Progress 01/01/01 to 12/31/01
Outputs
The major objective of this proposal is to study chemical reactions and biosynthetic pathways involving food lipids and antioxidants to improve food quality and human health. Two specific aims were proposed. Specific aim #1 was to alter oilseed storage reserves (lipid, carbohydrate, and protein) by genetic manipulation. We have successfully generated several sets of transgenic Arabidopsis plants containing constructs designed to alter expression of different acyl carrier protein (ACP; a key cofactor in plant fatty acid synthesis) isoforms. One set of plants has been well characterized involving overexpression of ACP-1 (a predominant seed isoform) in leaf tissue. This alteration of ACP pools has resulted in alterations of leaf fatty acid composition. This is the subject of the publication by Branen et al. (2001). This represents the first in vivo support that ACP isoforms play a role in determining the fatty acid composition of plants. Another set of plants includes
antisense expression of ACP-2 in seed tissue. We have achieved 5-30% reduction of oil content and are currently analyzing for alterations in protein and carbohydrate as a result of this manipulation. Another dramatic alteration observed is a major decrease in leaf lipids when the major isoform of ACP in leaf was decreased by antisense technology. These plants are being further investigated to obtain a better understanding of carbon partitioning in oilseeds. Both of these sets of plants will be the focus of our presentations at the International Plant Lipid Conference in Japan, May, 2002. Specific aim #2 was to evaluate the antioxidant effectiveness of honey. We have demonstrated the effectiveness of honey as an inhibitor of browning in fruit and vegetable homogenates (Chen et al., 2000) and as an inhibitor of lipid oxidation in cooked, ground poultry (McKibben et al., 2002). This meat research has generated much consumer interest, as the effectiveness of honey (added at 5% of the
weight of meat) was much greater than tocopherol or BHT. The next phase of this research has progressed rapidly. We are currently preparing a publication that will be an extensive analytical demonstration of the antioxidant components of honey. We have also developed a very sensitive antioxidant assay, the ORAC assay, for use in our laboratory. This assay has shown honey to be comparable to some fruits and vegetables on a per gram basis in terms of antioxidant effectiveness. We demonstrated the effectiveness of honey as an effective antioxidant in vitro against LDL oxidation in human blood serum. This work on the ORAC and LDL oxidation studies has been submitted for publication. This has led to a study on the dietary consumption of tea and honey to determine if the protection of honey against oxidative stress may be observed in a more in vivo situation. The data is just starting to be analyzed. We have also begun studies related to the effects of processing honey on the antioxidant
capacity of honey and of meat.
Impacts
Our lipid work has progressed to the point that much information will be obtained about the specific roles of ACP isoforms in plant fatty acid and lipid biosynthesis. We should also be able to gather important information about carbon partitioning in oilseeds from this work. ACP is proving to be quite effective as a tool for manipulation of lipids in plants. This could greatly impact the genetic engineering efforts in plant oils. Our honey work has demonstrated a great effectiveness of honey as a source of antioxidants both in food systems and potentially for human health. Although honey is not consumed in as large a quantity as fruits and vegetables our work demonstrates that it may very well be worth substitution of honey for a fair amount of the "empty" calories typically consumed as sugar.
Publications
- BRANEN, J., CHIOU, T.-J. and ENGESETH, N.J. 2001. Overexpression of acyl carrier protein-1 alters fatty acid composition of leaf tissue in Arabidopsis. Plant Phys. 127:222-229.
- MCKIBBEN, J. and ENGESETH, N.J. 2002. Honey as a protective agent against lipid oxidation in muscle foods. J. Agric. Food Chem. (In Press).
- GHELDOF, N. and ENGESETH, N.J. 2002. Antioxidant capacity of honeys from various floral sources based on the determination of oxygen radical absorbance capacity and inhibition of in vitro lipoprotein oxidation in human serum samples. (Submitted).
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Progress 01/01/00 to 12/31/00
Outputs
The major objective of our research is to study chemical reactions and biosynthetic pathways involving food lipids and antioxidants to improve food quality and human health. Two specific aims were proposed and the progress on each will be described. Specific aim #1 is to alter oilseed storage reserves (lipid, protein and carbohydrate) by genetic manipulation. We successfully generated transgenic plants containing various constructs designed to alter expression of different acyl carrier protein (ACP; a key cofactor in plant fatty acid synthesis) isoforms. Our primary focus thus far has been on further characterizing one set of transgenic plants which have significantly increased levels of a seed specific isoform of ACP in leaf tissue. We have recently submitted this work for publication. This is very significant, as it is the first in vivo report of ACP isoforms actually demonstrating specificity for specific acyl chains. These findings have led to our initiation of
studies on the promoter of this ACP isoform, as it may have significance in determining tissue specific expression. A set of transgenic Arabidopsis plants has been generated with various segments of promoter fragment driving GUS gene expression to be able to determine segments of the promoter that will dictate tissue specific expression. We are characterizing the promoter in an effort to be able to use it in this study to alter ACP levels in oilseeds as well as in other experiments designed to alter fatty acid/lipid composition in an effort to better understand oilseed storage reserve deposition and to create healthier oils. Additionally, we have initiated structural studies of this protein. We have also generated another set of transgenic plants with reduced fatty acid deposition due to antisense manipulation of another ACP isoform. We are in the process of characterizing these plants in greater detail. Our second specific aim was to evaluate the antioxidant content of honey and the
effectiveness of honey in inhibition of enzymatic browning of fruits and vegetables and in inhibition of lipid oxidation in meat systems. The fruit and vegetable work has recently been published in the Journal of Agriculture and Food Chemistry. The meat work has been submitted for publication. The second phase of this research - characterization and identification of antioxidant components of the various honeys is proceeding. We have characterized the flavonoid and phenolic acid components of the various honeys by HPLC and are in the process of identifying key components by LC/MS. Antioxidant capacity of the isolated components has begun using the ORAC assay, a very sensitive method for establishing in vitro antioxidant capacity, which we have just recently started using in our laboratory. There are distinct differences between honeys from different floral sources. This work has been submitted for presentation at the Institute of Food Technologists annual meeting. Ames assays are
demonstrating antimutagenic effects of our honeys when used in the presence of common mutagens encountered in foods; this is to be followed by analysis of antimutagenic effects of individual isolated components from honeys.
Impacts
By association of ACP isoforms with fatty acid composition we may be shedding light on a fundamental process, allowing better design of oilseeds for enhanced nutritional value and food quality. We are also closer to our original goal of being able to reduce oil content in seeds in an effort to learn more about seed storage deposition. Our antioxidant work has generated interest in the food industry by unveiling the importance of honey as a source of natural antioxidants, leading to enhancement of food quality and nutritional value. We are close to being able to predict the potential of honey, and individual components therein, as a dietary antioxidant.
Publications
- Chen, L., Mehta, A., Berenbaum, M., Zangerl, A. and Engeseth, N.J. 2000. Honeys from different floral sources as inhibitors of enzymatic browning in fruit and vegetable homogenates. J. Agric. Food Chem. 48(10):4997-5000.
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Progress 01/01/99 to 12/31/99
Outputs
The major objective of our research is to study chemical reactions and biosynthetic pathways involving food lipids and antioxidants to improve food quality and human health. Two specific aims were proposed and the progress on each will be described. Specific Aim #1 is to alter oilseed storage reserves (lipid, protein and carbohydrate) by genetic manipulation. We successfully generated transgenic plants containing various constructs designed to alter expression of different acyl carrier protein (ACP; a key cofactor in plant fatty acid synthesis) isoforms. Our primary focus thus far has been on further characterizing one set of transgenic plants which have significantly increased levels of a seed-specific isoform of ACP in leaf tissue. We are in the process of putting together final figures/data for a publication of this work. This is very significant, as it is one of the first in vivo reports of ACP isoforms actually demonstrating specificity for specific acyl chains.
These findings have led to our initiation of studies on the promoter of this ACP isoform, as it may have significance in determining tissue-specific expression. We are characterizing the promoter in an effort to be able to use it in this study to alter ACP levels in oilseeds as well as in other experiments designed to alter fatty acid/lipid composition in an effort to better understand oilseed storage reserve deposition and to create healthier oils. Additionally, we are in the process of purifying large quantities of this protein in an effort to conduct some structural studies to understand the interactions with other key fatty acid biosynthetic enzymes. We have also initiated analysis of a number of other plants that we have transformed to alter levels of additional ACP isoforms. Our second Specific Aim was to evaluate the antioxidant content of honey and the effectiveness of honey in inhibition of enzymatic browning of fruits and vegetables and in inhibition of lipid oxidation in
meat systems. These two projects were both presented at the annual meeting of the Institute of Food Technologists and have been submitted for publication. We are now beginning the next phase of this research, which is to separate, identify and quantitate antioxidant components of the various honeys. In addition to conducting assays to quantitate ascorbic acid and tocopherols, we have initiated column chromatographic separation of phenolic acids and flavonoid components and are in the process of identifying them and quantitating them by HPLC analysis. We will confirm identity of some of the unknowns using LC/MS. This research is showing distinct differences between honeys from different floral sources. We are also in the initial stages of conducting Ames assays for mutagenicity and antimutagenicity on the extracts as well as isolated components in order to determine their potential biological activity.
Impacts
By association of ACP isoforms with fatty acid composition we may be shedding light on a fundamental process, allowing better design of oilseeds for enhanced nutritional value and food quality. Our antioxidant work has generated interest in the food industry by unveiling the importance of honey as a source of natural antioxidants, leading to enhancement of food quality and nutritional value.
Publications
- MCKIBBEN, J. and ENGESETH, N.J. 2000. Honey as a protective agent against lipid oxidation in muscle foods (Submitted).
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Progress 06/01/98 to 09/30/98
Outputs
The major objective of our research is to study chemical reactions and biosynthetic pathways involving food lipids and antioxidants to improve food quality and human health. Two specific aims were proposed. Specific aim #1 is to alter oilseed storage reserves (lipid, protein and carbohydrate) by genetic manipulation. We generated transgenic plants containing constructs designed to alter expression of different acyl carrier protein (ACP; a key cofactor in plant fatty acid synthesis) isoforms. Our primary focus thus far has been on further characterizing one set of transgenic plants which have significantly increased levels of a seed specific isoform of ACP in leaf tissue. We have verified enhanced levels of this ACP isoform in leaf tissue by Western and Northern analysis. Overexpression of ACP-1 in leaf has resulted in an alteration of fatty acid composition. Specific alterations include a decrease in 16:3, 18:1 and 18:2 levels and an increase in 18:3 fatty acids. This
is very significant, as it is one of the first in vivo reports of ACP isoforms actually demonstrating specificity for specific acyl chains. We are in the process of putting this material together for publication and will be presenting at the National Plant Lipid Meeting in Tahoe this summer. We have also generated plants using antisense constructs to another ACP isoform (ACP-2). Northern analysis of leaf tissue has demonstrated an approximately 50% reduction in ACP-2 RNA in this set of transgenic plants. We have detected no differences in ACP profile of leaf tissue by Western analysis. We are currently bulking up on seed to do more characterization of RNA levels, fatty acids and lipids in these seeds. Information thus far gained has greatly clarified the potential role of several ACP isoforms in vivo in plants. Additionally, this research has provided strong preliminary data for applying for federal funding. Specific Aim #2 was to evaluate the antioxidant content of honey and the
effectiveness of honey in inhibition of enzymatic browning of fruits and vegetables and in inhibition of lipid oxidation in meat systems. These two projects were both presented at the annual meeting of the Institute of Food Technologists, June, 1998. We have demonstrated wide variation in the antioxidant content of honeys from various floral sources and likewise, varying abilities to protect against oxidative deterioration in foods. Soy honey was particularly effective at prevention of enzymatic browning in fruits and vegetables compared to clover honey, which had similar antioxidant levels. Prevention of lipid oxidation in cooked, ground turkey was also provided by various honeys; their ability to prevent oxidation increased with increasing antioxidant content. Honey was much more effective at 5%(w/w)of addition compared to synthetic antioxidants at the normally accepted levels (0.02% of fat). Both of these projects were also presented in the cover story of the September 11, 1998
issue of Science News. We are currently preparing two manuscripts as well as initiating the next step of this work,which is to isolate, quantify and characterize the components that serve as antioxidants in these honeys.
Impacts
(N/A)
Publications
- No publications reported this period
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