Progress 11/01/10 to 10/31/15
Outputs
OUTPUTS: During past ten years we have achieved scientific progresses and accumulated many publications in the phytochemical research. Now growing fruit and vegetables and fruits with higher amounts of health benefiting compounds became common knowledge and most people understand their importance in our diet for a higher living standard. In this report period, we have developed several methods to measure the quantities of these compounds in food in a fast and accurate manner. We have provided analytical services of onion testing to many onion growers around country and helped them to market sweet onions with a premium price PARTICIPANTS: Dr. Eun Jin Lee did major contribution to my research and Dr. Patil provided support and administrative leadership. Several graduate students also helped in specific projects. TARGET AUDIENCES: My main research target was vegetable researchers and growers with communication through publications in professional journals. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
We have developed an automated method to measure the total phenolic content in samples with a high speed and accuracy, which can be adopted in breeding and other quality testing labs. This application would help screen breeding lines for higher content of phytochemicals. We have also tested different cultural conditions on the contents of various compounds for the production of healthier foods. A treatment of UV light to the sprouting onion leaves resulted in elevated quercetin contents, which opens an idea that we may improve food quality even after harvesting the onion bulbs.
Publications
- Kil Sun Yoo, Haejeen Bang, Eun Jin Lee, Kevin Crosby, Bhimanagouda S. Patil. 2012. Variation of carotenoid, sugar, and ascorbic acid concentrations in watermelon Genotypes and Genetic. Horticulture, Environment, Biotechnology Horticulture, Environment, & Biotechnology 53(60):552-560.
- Kil Sun Yoo, Eun Jin Lee, Daniel Leskovar, and Bhimanagouda S. Patil (2012. Dec) Development of an automated method for Folin-Ciocalteu total phenolic assay in artichoke extracts. Journal of Food Science, 77(12):C1279-C1284
- Kil Sun Yoo, Eun Jin Lee, Bhimanagouda S. Patil 2012. Changes in flavor precursor, pungency, and sugar contents in shortday onion bulbs during five month storage at various temperatures and controlled-atmosphere. Journal of Food Science, 77(2):C216-C221
- Eun Jin Lee, Yohannes H. Rezenom, David H. Russell, Kil Sun Yoo, and Bhimanagouda S. Patil (2012. Apr.) Elucidation of chemical structures of pink-red pigments responsible for 'pinking' in macerated onion (Allium cepa L.) using HPLC-DAD and tandem mass spectrometry. Food Chemistry, 131(3):852-861
- Eun Jin Lee, Kil Sun Yoo, Bhimanagouda S. Patil (2012. Mar.) Freeze-dried fresh onion powder prevents green discolouration in macerated garlic. Food Chemistry, 131(2):397-404.
- Jungeun Cho, Eun Jin Lee, Kil Sun Yoo, Seung Koo Lee (2012. Jan.) Role of precursors on greening in crushed garlic (Allium sativum) bulbs, and its control with freeze-dried onion powder. Journal of the Science of Food and Agriculture, 92(2):246-252.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: I have continued research on phytochemical analysis at the VFIC on carotenes, pyruvic acid, vitamin C, flavonoids, cynarin compounds in onions, peppers, carrots, spinach, watermelon, artichoke for my own project and collaboration with other VFIC scientists. Pigment analysis in beet was continued. Technical advice was provided to graduate students who are working on analysis of phytochemicals using HPLC and other instruments and maintenance and repairs of those instruments were also provided. I have provided custom onion pyruvic acid and other phytochemical analysis services for both VFIC member and non-member companies. Five referred papers and 1 abstract were published and presented. I also gave lectures at two classes as a guest speaker and introduced my research results. Visiting scientist Dr. Eun Jin Lee has been collaborating in many research areas. PARTICIPANTS: Dr. Eun Jin Lee, a visiting scientist from Korea, was a key participant in these works. She dis sample preparation, extraction, and analysis works with me. TARGET AUDIENCES: My research was mainly targeting the researchers in the vegetable sciences and reserch findings were presented at a professional meeting (ASHS). PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
We have worked to characterize & isolate the pink color compound in the onion macerates and to compare different cultivars for the pink coloration. We have purified and identified the target red pigments by HPLC-MS method. They are not a single compound but a mixture of many different related compounds. Using the MS data, we have proposed possible structures of those compounds, which was the first in the area. We also did a study on a survey of cultivation of Swiss chard and its antioxidant and biological activities. We developed an HPLC method to analyze the color compounds and identified them. We are at the stage of comparing cultivars and locations on the contents of these compounds. The health benefits of these compounds are not well known yet and need further studies.
Publications
- Yoo KS, Lee EJ, Patil BS. 2011. Underestimation of pyruvic acid concentrations by fructose and cysteine in 2,4-dinitrophenylhydrazine-mediated onion pungency test. J Food Sci 76:1136-1142.
- Lee EJ, Yoo KS, Patil BS. 2011. Total carotenenoid, anthocyanin, and sugarin sliced or whole purple (cv. BataSweet) and orange carrots during 4-week cold storage. Hort Environ Biotech. 52(4): 402-407.
- Yoo KS, Lee EJ, Patil BS. 2011. Improved consistency in DNPH-mediated pyruvic acid analysis of onion juice by modifying the sample processing order. J Food Sci 76:162-167.
- Bang H, Cho DY, Yoo KS, Yoon MK, Patil BS, Kim S. 2011. Development of simple PCR-based marker linked to the Ms locus, a restorer-of fertility gene in onion (Allium cepa L.). Euphytica 179:439-449.
- Shinohara T, Agehara S, Yoo KS, Leskovar D. 2011. Irrigation and nitrogen management of artichoke: Yield, head quality, and phenolic content. HortScience 46(3)1-10.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: We have continued our research on the phytochemical changes in the fruits and vegetables and provided knowledge to science community and industry. We have grown beet, swiss chard,and asparagus and tested for their potential phytochemicals for the increased interest and consumption as new crops to Texas vegetable growers. PARTICIPANTS: Dr. Eun Jin Lee has been a major contributor in the research as a post doc research associate. Dr. John Jifon provided plant samples grown from fields. Drs Crosby, Leskorvar, and Byrne also provided occasional samples for the study. Dr. Patil provided financial support to the lab personnel and Dr. Lee. We had a undergraduate student worker and taught her various sample processing techniques. TARGET AUDIENCES: Main target audience of our research were scientific community. We presented our finding to research journals and conferences. We also had contacts with Texas vegetable growers and introduced new vegetables and their health benefits. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In the beet and Swiss chard, we have isolated the red and yellow pigments, betacyanins and betaxanthins,and quantified them from the crops grown at greenhouse and field. We also have developed HPLC method to quantify flavonoid (rutin) and protodiscin simultaneously from asparagus. This finding will enable to reduce the HPLC run time and cost of analysis. We are hoping that these results would be continued to the purification and further study using cell- and animal-study to test if these compounds have any specific health benefits.
Publications
- Eun Jin Lee, Kil Sun Yoo, Bhimanagouda S. Patil. 2010. Identification of candidate amino acids in the formation of pink-red pigments in onion (Allium cepa L.) juice and separation by HPLC. Journal of Food Science, 75:684-689.
- Eun Jin Lee, Kil Sun Yoo, Bhimanagouda S. Patil. 2010. Development of rapid HPLC-UV method for simultaneous quantification of protodioscin and rutin in white and green asparagus spears. Journal of Food Science, 75:703-709.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: I have continued phytochemical analysis research at VFIC on carotenes, pyruvic acid, vitamin C, flavonoids, cynarin compounds in onions, peppers, carrots, spinach, watermelon, artichoke for my own project and collaboration with other VFIC scientists. Technical advice was provided to graduate students who are working on analysis of phytochemicals using HPLC and other instruments and maintenance and repairs of those instruments were provided. I have provided custom onion pyruvic acid and other phytochemical analysis services for both VFIC member and non member companies. Two referred papers, 5 conference proceeding, and 1 abstract were published or presented. I also gave lectures at two classes as a guest speaker and introduced my research results. Visiting scientist Dr. Eun Jin Lee has been collaborating in many research areas. Two undergraduate students were hired and worked in my lab to assist the chemical analysis. I have presented the importance of phytochemicals in fruits and vegetables and eating healthy diets to maintain and improve our general health to many visitors to the VFIC. PARTICIPANTS: Bhimu Patil, Director, Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University (collaborator). Kevin Crosby, Department of Horticultural Sciences, Texas A&M University (Collaborator). John Jifon, Texas A&M Agrilife Research and Extension Center, Weslaco, Texas, (Collaborator). Daniel Leskovar, Texas A&M Agrilife Research and Extension Center, Uvalde, Texas, (Collaborator). Eun Jin Lee, Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University (Collaborator). TARGET AUDIENCES: My main audiences are researchers in the phytochemical research, growers at South Texas areas, and graduate students at the VFIC. New information obtained from my research will provide better understanding on how to measure quality of the produce. Growers of vegetables in Texas or other States (Onions, peppers, carrots) will get benefits by using the research output in producing better quality crops. I also provide technical advice to those students at the Center in analytical research. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
I have investigated the pinking coloration in onion juice which was kept for several days after blending. This phenomenon was reported for decades but was not understood well yet. It was very similar to the greening coloration in garlic. When individual amino acid was mixed with 1-propenyl thiosulfinate (or onion juice) many different pink compounds were generated and these could be separated by an HPLC method. I tried to concentrate and purify each compound but could not succeed. The mixtures of the compounds were fairly complex and quantity was low, thus, separation and purification by using a preparative column was difficult. The crude samples were tested for estimation of mass and many peaks were generated and accurate measurement of the mass was not able. As a part of searching new vegetable crop for Texas, beet and Swiss chard were grown and separation of the red and yellow compounds is being tested. Since those compounds were long known to be beneficial to several health problems, I am anticipated to find new efficacy of these compounds and expand the growth of these crops in Texas.
Publications
- Lee, E.J., K.S. Yoo, J. Jifon, and B. Patil. 2009. Characterization of shortday onion cultivars of 3 pungency levels with flavor precursor, free amino acid, sulfur, and sugar contents. J. Food Sci. 74(6). C475-480.
- Lee, E.J., K.S. Yoo, J. Jifon, and B.S. Patil. 2009. Application of extra sulfur to high-sulfur soils does not increase pungency and related compounds in shortday onions. Sci. Hort. 123:178-193.
- Bang, H, L.M. Pike, B.S. Patil, and K.S. Yoo. 2009. Structural gene expression in carotenoid biosynthetic pathway of carrot during root development. Proc. 2nd IS on Human Health Effects of FAV. Ed. B. Patil. Acta Hort. 841:475-478.
- Cho, J.E., S.K.Lee, B.Patil, E.J. Lee, and K.S. Yoo. 2009. Separation of blue pigments in crushed garlic cloves: the color forming potential of individual amino acids. Proc. 2nd IS on Human Health Effects of FAV. Ed. B. Patil. Acta Hort. 841:491-493.
- Crosby, K. M., J.L. Jifon, D.L. Leskovar, and K.S. Yoo. 2009. Novel vegetable cultivars from TAMU- Improving human health benefits, flavor and productivity. Proc. 2nd IS on Human Health Effects of FAV. Ed. B. Patil. Acta Hort. 841:499-501.
- Lee, E.J., K.S.Yoo, B. Patil, J.E. Cho, and S.K. Lee. 2009. Flavor precursor and amino acids involved in blue-green pigment formation in crushed garlic cloves. Proc. 2nd IS on Human Health Effects of FAV. Ed. B. Patil. Acta Hort. 841:541-544.
- Vikram, M., Y. Feng, S.H. Park, K.S. Yoo, and H. Koiwa. 2009. Designing a molecular switch to optimize phenylpropanoid neutraceuticals in vegetables. Proc. 2nd IS on Human Health Effects of FAV. Ed. B. Patil. Acta Hort. 841:615-618.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: I have continued my research on phytochemical analysis in peppers, carrots, onions, artichoke, spinach, etc. from my own experiments and other collaborators. The target compounds are vitamin C, flavonoids, carotenes, anthocyanins, and cynarin. Advanced breeding lines of extra mild onions from Dr. Leonard Pike breeding program were grown to confirm their mildness with help of John Jifon at Weslaco Station. Quality changes of sliced BetaSweet carrot were tested to support J&D Produce. Quality assurance in such product is critical for the fresh-cut produce industry. We hope that that minimally processed product would be more popular to the customers and production of the product would be increased significantly to benefit the carrot production in Texas. I have provided custom analysis in onion pungency and capsaicins in peppers for the VFIC member companies for quality test or breeding purposes. I have attended ASHS and ACS annual meetings and presented my research outcomes. I also attended the Rio Grande Horticulture meeting and exchanged information in my research areas. I have assisted and advised graduate students in the VFIC on chemical analysis. Three undergraduate students were hired and worked in my lab to assist the chemical analysis. I have presented the importance of phytochemicals in fruits and vegetables and eating healthy diets to maintain and improve our general health to many visitors to the VFIC. PARTICIPANTS: Bhimu Patil, Director, Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University (collaborator). Kevin Crosby, Department of Horticultural Sciences, Texas A&M University (Collaborator). John Jifon, Texas A&M Agrilife Research and Extension Center, Weslaco, Texas, (Collaborator). Daniel Leskovar, Texas A&M Agrilife Research and Extension Center, Uvalde, Texas, (Collaborator). Eun Jin Lee, Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University (Collaborator). TARGET AUDIENCES: My main audiences are graduate students and researcher in the phytochemical research. New information obtained from my research will provide better understanding on how to measure quality of the produce. Growers of vegetables in Texas or other States (Onions, peppers, carrots) will get benefits by using the research output in producing better quality crops. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Unidentified blue-green pigments were occasionally formed when macerated garlic cloves were kept a while and that creates some marketing problems in the minced garlic products. We investigated the garlic discoloration by using mixtures of garlic and onion juices and purified flavor precursors, trans-(+)-S-1-propenyl-L-cysteine sulfoxide (1-PeCSO, isoalliin) from onion and (+)-S-2-propenyl -L-cysteine sulfoxide (2-PeCSO, alliin) from garlic. The pigment formation was associated with an alliinase activity and the increased levels of flavor precursors, particularly1-PeCSO, and several amino acids. Vivid-blue color pigment was successfully produced by reacting only 1-PeCSO and 2-PeCSO, purified alliinase, and glycine. Various amino acids and thiosulfinates produced different bluish pigments. At least 10 naturally occurring blue pigments were separated from discolored garlic extracts by using HPLC and detector set to 580 nm. Nearly all amino acids (except for cysteine, proline, and 4-hydroxy-proline) could form blue and purple pigments. These pigments were believed to be formed by reaction between various amino acids and mixture of thiosulfinates which were originated from alliinase reaction on 1-PeCSO and 2-PeCSO. Onion pungency is measured by reading color intensities of wine pink color after adding NaOH to the heated mixture of dinitrophenyl hydrazine (DNPH) and onion juice. Though expected to be similar, significant variation was reported among several modifications of the original SW method. In our own test, we have observed about 20-30% differences in pyruvic acid concentrations between our automated method and a method using manual reading of absorbency. To elucidate the source of the difference, we collected juices from 40 onion bulbs of four colors and measured pyruvic acid concentrations by four different methods; an automated system, high performance liquid chromatography (HPLC), manual spectrophotometric (SP), and the original SW methods. The automated, HPLC, and SW methods showed highly significant correlations and had similar pungency levels. However, the SP method has estimated about 10 to 30% less pyruvic acid than the automated and HPLC methods. The absorbency reading of the undiluted juice samples in SP method was decreasing very rapidly, as compared to the pyruvic acid standard, and resulted in lower estimation in the pyruvic cid concentration in the samples by about 20-30%. The difference became greater as the reading time was extended. After all, by reading absorbency at around 30 second after adding NaOH, we could obtain very similar pyruvic acid concentrations between the automated and the SP methods. We have provided information on the discoloration of minced garlic products and measuring onion pungency more consistently and accurately to food processor and onion producers/buyers for quality control.
Publications
- Perez, J.L., G.K. Jayaprakasha, K.S. Yoo, and B.S. Patil. 2008. Development of a method for the quantification of D-glucaric acid in different varieties of grapefruits by high-performance liquid chromatography and mass spectra. J. Chrom. A. 1190:394-397.
- Girennavar, B., Jayaprakasha, G.K., Simpkins, S.E., Maxim, J., Yoo, K.S. and Patil, B.S. 2008. Influence of Electron Beam Irradiation on Bioactive Compounds in Grapefruits (Citrus paradisi Macf.). J. Agric. Food Chem. 56(22):10941-6.
- Cho, J.E., Lee, E.J., Yoo, K.S., Lee, S.K. and Patil, B.S. 2008. Identification of candidate amino acids in the formation of blue pigments in crushed garlic cloves (Allium sativum L.). J. Food Sci. 74(1): c11-c16.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: My main activity is phytochemical analysis in peppers, carrots, onions, artichoke, spinach, etc. from my own experiments and other collaborators. The target compounds are vitamin C, flavonoids, carotenes, anthocyanins, and cynarin. I have grown onions at three fields of south Texas with additional sulfur nutrition to see increase of pungency. This research was collaborated with Dr. John Jifon at the Weslaco Experiment Station. Advanced breeding lines from Dr. Leonard Pike were grown to confirm their mildness. An exchange graduate student from Korea was trained in the analysis works for a year and two undergraduate students were hired to work in my lab. Several other graduate students from Dr. Bhimu Patil's lab were supported in HPLC analysis. I have attended conferences and meetings and presented my research works. In Georgia Fruit and Vegetable Growers Association Annual meeting, I presented on Texas onion industry and research. At ASHS meeting, several abstracts were
presented with other collaborators. FAV 2007 International Conference was held at Houston and I presented two invited talks. Phytochemical research works were presented at Texas Pepper Conference in November.
PARTICIPANTS: Dr. John Jifon, Weslaco Agricultural Experiment Station, has helped in growing onions at the fields and harvesting the onion bulbs. Dr. Eun Jin Lee, Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843. She participated in the lab analysis of the samples and collected data. Jeung Eun Cho, Department of Plant Science, Seoul National Univeristy, Seoul, Korea. Graduate Student. She helped in the analysis and data collection.
TARGET AUDIENCES: Growers (vegetable and fruit) for educating the importance of phytochemicals in the products and how to improve the quality. Scientific community-presented research output and exchanged information on the analysis of the phytochemicals and changes by pre and post harvest conditions. General audience- many visitors to the VFIC and presented our research and educated the importance of eating fruits and vegetable in quantity and on a regular basis.
Impacts
Pungency and flavor precursor compounds in four onion cultivars were measured to determine the effect of extra sulfur applications to the fields with sufficient S levels. Four onion cultivars, Cougar, Legend, Texas Early White, and TG 1015Y were grown in three different fields of the Rio Grande Valley areas of Texas with varying levels of soil S from 30 to 235 ppm. Pyruvic acid, bulb weight, soluble solids content, trans-(+)-S-1-propenyl-L-cysteine sulfoxide, methyl-(+)-S-sulfoxide, methionine, and cysteine were measured. The pungency levels of onions were not linearly influenced by soil S levels in all cultivars, regardless of the fields. For examples, there were no differences in pungency levels of onions grown at 30 ppm S or at 160 ppm S in Legend and TEW onions. Pyruvic acid levels of each cultivar were in the order of Legend, Cougar, TG 1015Y, and TEW onions and the levels were, 4.7, 4.8, 5.2, 7.8 umole/ml, respectively. In order to maintain the consistent
mildness and to keep the confidence of the consumer, it is pertinent to ensure the test results are consistent among laboratories. We have compared onion pungency test methods and figured out why there have been about 30% differences between the automated method I am using and the manual method which is being used at Weslaco Station. The color compounds representing the pyruvic acid levels degrade very rapidly and this degradation was the cause of underestimation of the pungency in the manual method. From this research, we can obtain very consistent results by measuring the color promptly after the complete chemical reactions. Out of these studies, we concluded that mild sweet onions can be produced from South Texas fields, even if the sulfur levels were already high, only if we choose right onion varieties. The mildness of the onion bulbs can be accurately tested by using the method we modified as in this study. We believe that Texas onion growers can get benefits in producing high
quality sweet onions and in confirming the sweetness of the onions.
Publications
- Leskovar, D.I., Goreta, S., Piccinni, G. and Yoo, K.S. 2007. Strategies for globe artichoke introduction in South Texas. Acta Horticulturae. 630:157-163.
- Yoo, K.S., Pike, L., Patil, B., Leskovar, D., Crosby, K. and King, S. 2007. Challenges of phytochemical analysis and its application in developing new fruits and vegetables with improved health benefits. Acta Horticulturae. 744:101-106.
- Crosby, K., Jifon, J, Pike, L. and Yoo. K.S. 2007. Breeding vegetables for optimum levels of phytochemicals. Acta Horticulturae. 744:219-224.
- Leskovar, D., Bang, H., Kim, S.K., Yoo, K.S., King, S.R., and Crosby, K. 2007. Environmental and Genetic Factors on Carotenoids and Quality in Watermelon Fruits. Acta Horticulturae. 744:233-241.
- Kim, S,G., Yoo, K.S. and Pike, L.M. 2007. Production of doubled haploid onions (Allium cepa) and evaluation of their field performance. Hort. Environ. Biotechnol. 48(3):143-147.
- Vanamala, J. Cobb, G, Loaiza, L., Yoo, K.S., Pike, L. and Patil, B.S. 2007. Ionizing radiation and marketing simulation on bioactive compounds and quality of grapefruit (Citrus paradise c.v. Rio Red). Food Chemistry 105:1404-1411.
- Kim, S.G., Yoo, K.S., and Pike, L. 2007. Estimation of variance of red color intensity of onion bulbs utilizing a new digital imaging quantification method. Hort. Environ. Biotechnol. 48:207-211.
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Progress 01/01/06 to 12/31/06
Outputs
Vegetables are a rich source of phytochemicals and the most efficient delivery system among foods. New cultivars with enhanced levels of phytochemicals have become more of interest in vegetable breeding, as consumers demand better quality products. I have been continuing this research in analysis of various phytochemicals in many different kinds of fruits and vegetables. Artichoke, a new crop in Texas, was tested to grow at Uvalde areas by Dr. Daniel Leskovar and I have measured vitamin C, total phenolic, cynarin, chlorogenic acid, and other flavonoids. The artichoke contains cynarin and it is known to lower cholesterol. Chlorogenci acid content ranged 1-3 mg/g, cynarin 2-8 mg/g, and flavonoid luteolin was low and ranged 10-130 ug/g dw. Total phenolic was 20-50 mg/g dw as chlorogenic acid. Fructan, polymers of fructose, levels were between 4- 15 g/100 dw. Vitamin C content was less than 50 ug/g fw and artichoke was not a good source of vitamin C. Spinach is a rich
source of lutein, beta-carotene, and vitamin C. Spinach samples from Uvalde showed 60-120 ug/g lutein and 30-55 ug/g beta carotene. Pepper samples from Kevin Crosby were tested and they contained up to 1200 ug vitamin C, 350 ug/g quercetin, 45 ug/g luteolin, and 450 ug/g total flavonoids, depending on pedigree. This data indicated that there is food possibility to breed new pepper varieties with higher levels of vitamin C, flavonoids, and with various levels of capsaicins. Testing onion pungency and quercetin content from various breeding lines and growers have been continued and new sweet onion cultivar release with Dr. Leonard Pike is under progress.
Impacts
Producing high quality crops with higher or optimal levels of phytochemical is an important issue in vegetable industry. Simply producing a large quantity does not mean an economic return. At VFIC, we like to develop new cultivars with enhanced health benefits and develop new techniques to grow crops with more benefits and efficiency. By testing the phytochemical levels, we may be able to screen new progeny with high/low levels of those interest compounds. The pepper breeder will use this information to screen his breeding lines to breed new cultivars with high vitamin C and flavonoids. Capsaicins, the hot components in peppers, are routinely tested to provide various levels of the heat. Spinach grown at different levels of irrigation was tested for carotene and lutein and production of spinach with minimal irrigation without reduction in quality will be studied in Uvalde areas.
Publications
- Sinclair, J., S.O. Park, K. Crosby, K.S. Yoo, and G.E. Lester. 2006. Identification and confirmation of RAPD marker and andromonoecious associated with quantitative trait loci for sugars in melon. J. Amer. Soc. Hort. Sci. 131:360-371.
- Yoo, K.S, L. Pike, K. Crosby, R. Jones, and D. Leskovar. 2006. Differences in onion pungency due to cultivars, growth environment, and bulb sizes. Scientia Horticulturae. 110:144-149.
- Kim, S.G., H.J. Bang, K.S. Yoo, and L.M. Pike. 2006. Identification of the fourth allele of the ANS (anthocyanin synthase) gene and its effect on red color intensity in onions (Allium cepa). Euphytica 149:45-51.
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Progress 01/01/05 to 12/31/05
Outputs
Extracts of onions (red skins, red edible portions, white skin, yellow skins, white garlic skins), artichokes, carrots with various colors (purple/orange, purple/yellow, yellow, red/orange) were made using ethanol/citric acid or acetone solvents. They were extracted and concentrated and need to be made into marketable packages (capsule or tablet) by a commercial company.
Impacts
Food suppements are good delivery system for people who cannot consume regualar fresh fruits and vegetables for various reasons. We are developing these products to utilize culls in the fields and make a profits for the manyfacturing industry. These new natural products can be commercialized to provide many health benefits of vegetables we developed for higher levels of functional compounds to the consumers.
Publications
- Kim, S., K.S. Yoo, L.M. Pike. 2004. Inheritance of a factor controlling chalcone synthase transcription determines white coloration in onions (Allium cepa). Plant Sci., accepted.
- Crosby, K.M., Leskovar, D.I. and Yoo, K.S. 2004. TAM Mild Habanero, a low pungency Habanero pepper. HortScience 40(2): 490-491.
- Vanamala, J., L. Reddivari, K. S. Yoo. L. M. Pike, B. S. Patil. 2005. Variation in bioactive flavonoid content of commercial brands of orange juices. J. Food Composition and Analysis. 19:157-166.
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Progress 01/01/04 to 12/31/04
Outputs
Pungency in onions is caused by volatile sulfur compounds, the absence of which produce the milder, more pleasant and desirable onion flavor. The etiology of onion pungency is complex and can be influenced by a variety of genetic and environmental factors. This study was conducted to determine the onion pungency variations due solely to environmental effects by using cloned plants, in order to eliminate genetic heterogeneity. Cloned onions, possessing various genetic characteristics, were grown in three fields in the Rio Grande Valley, about 10 and 45 km apart from Weslaco, Texas, and in a greenhouse at College Station, Texas 600 km to the north. We determined that genetic diversity was the major determining factor of onion pungency (82% of total variation), but there were also considerable pungency differences with regard to the field in which they were grown (11%). The maximum difference among pungency levels measured among fields was 1.3 umol ml-1, while that of
individual bulbs was 2.3 umol ml-1. The pungency levels were not correlated with soil sulfur (S) nutrition levels, which varied between 16 and 97 ppm. We observed no growth location pungency differences (field or greenhouse) among the12 clones (3.86 vs. 3.82 umol ml-1), though individual clones showed a maximum of 0.7 umol ml-1 difference. When onion pungency levels from individual bulbs of 29 clones were compared between a given field and greenhouse, there was little correlation between locations (maximum difference of 3.5 umol ml-1). Within clones, there was a slight trend of onion pungency levels inversely correlating with increasing bulb weight. Though non-significant, this trend could not be explained by the dilution effect. The mean coefficient of variation was 8, 11 and 21% in clonal lines, commercial hybrid cultivars, and open pollinated (OP) lines, respectively. Though onion pungency differs considerably by growing conditions, the selection of mild flavored onion-producing
cultivars is considered as the best way to produce mild onions.
Impacts
Producing onions with uniform pungency is important in the onion industry, as the demand of milder onions increased and a few pungent onion in a population can be a source of consumer complaints. In this study we produced genetically identical cloned onion plants and grew them in three fields and in a greenhouse and determined variation in onion pungency, which was due solely from environmental effects.
Publications
- Kim S, Binzel M, Yoo K, Park S, Pike LM (2004) Pink (P), a new locus responsible for a pink trait in onions (Allium cepa) resulting from natural mutations of anthocyanidin synthase. Mol Gen Genomics 272:18-27.
- Kim S, Binzel M, Yoo K, Park S, Pike LM (2004) Inactivation of DFR (Dihydroflavonol 4-reductase) gene transcription results in blockage of anthocyanin production in yellow onions (Allium cepa). Mol Breed 14:253-263.
- Kim S, Jones R, Yoo K, Pike LM (2004) Gold color in onions (Allium cepa): a natural mutation of the chalcone isomerase gene resulting in a pre-mature stop codon. Mol Gen Genomics 272:411-419. Kim S, Yoo K, Pike LM (2004) Development of a PCR-based marker utilizing a deletion mutation in the DFR (dihydroflavonol 4-reductase) gene responsible for the lack of anthocyanin production in yellow onions (Allium cepa). Theor Appl Genet, in press.
- Kim S, Yoo K, Pike LM (2004) Development of a codominant PCR-based marker for an allelic selection of the pink trait in onions (Allium cepa) based on the insertion mutation in the promoter of the anthocyanidin synthase gene. Theor Appl Genet, in press.
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Progress 01/01/03 to 12/31/03
Outputs
This year research was focused on identifying and quantification of carotenes, ascorbic acid, and sugars in watermelons. About 55 watermelon samples with various flesh colors (red, pink, orange, and yellow) were tested after they were grown at Weslaco by Dr. Kevin Crosby. Since carotenes are of interest in their health benefit effects as antioxidant and pro-vitamin, profiles of carotene were examined to provide basic information of individual cultivar to breeders. Sugar content is also a primary factor in a watermelon breeding program and higher level is desirable. I also surveyed ascorbic acid content as an additional health benefit aspect. In order to identify and quantify, carotene compounds were extracted by acetone and phase-separated into hexane. The hexane extracts were dried by nitrogen stream and reconstituted with acetone. The profiles of carotene were examined by an HPLC analysis. The individual compound was identified by comparing HPLC peak pattern and
spectrum of each compound with that of the standard compound. Red and pink colored watermelon contained lycopene as the major carotene with wide range of variation in total carotenes (13 - 55 ug/g). Beta-carotene was the second major carotene and ranged less than 4 ug/g. There were also lutein and violazanthin in less than 1 ug/g. Yellow and orange flesh watermelons contained a complex mixture of carotenes. Prolycopene, lycopene, or beta-carotene was the major component, depending on the variety and the contents were less than 25, 5, and 5 ug/g, respectively. There were also minor carotenes, such as violaxanthin, lutein, neurosporene, zea-carotene with a 0 - 5 ug/g range. Neurosporene, zea-carotene, and prolycopene were not found in the red watermelons. There was great variation in total sugar content, range being from 45 to 90 mg/g, while the brix was from 5.5 to 15.5. Sucrose, glucose, and fructose were the main sugars in the watermelon and their composition were grouped as
sucrose-dominant or fructose- dominant groups. Some varieties with very low levels of sucrose were generally low in the total sugar content. Watermelon contained fairly low levels of ascorbic acid, less than 50 ug/g. Some varieties had nearly no ascorbic acid.
Impacts
The results of this research will provide basic information to breeders to identify watermelon varieties for profiles and their compositions of carotene, sugar and vitamin C. Using this result, a breeder can select parent of test crosses to develop higher levels of carotene, sugar, and vitamin C or a molecular makers can be found to develop new varieties. This research is believed to be the first of its kind to identify the carotenes in the yellow and orange watermelons.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
Developing a new health-benefiting product from BetaSweet carrot is under progress. The concept is to make a dried powder and extract of anthocyanins and carotene from the BS carrots and test for feasibility of developing a new product in forms of capsule or tablet. A.Identifying anthocyanin compounds The BS carrot anthocyanins were extracted, purified, and tested by an HPLC system and LC-MS system to identify the individual anthocyanin compound. The carrot extract were injected and separated by an HPLC system with the same conditions of a previous report. The retention time of five peaks was compared with the data and they were tentatively identified. The spectra of the each peak compound were also compared with the spectral data and this comparison resulted in further confirmation of those compounds. Lastly, an LC-MS method was tested to confirm the results of those two listed methods. This test was done as collaborative research by Dr. Shane Tichy of the
Mass-spectrometry laboratory of the Chemistry Department. Five compounds identified were all cyanidin compounds with 1) xylosyl- glucosy-galactoside, 2) xylosyl galactoside, 3) sinapoyl - xylosyl- glucosyl - galactoside, 4) ferulyl-xylosyl- glucosyl - galactoside, 5) 4-coumaroyl - xylosyl- glucosyl - galactoside. B.Extraction and concentration of anthocyanin and carotene One kg fresh BetaSweet carrot was blended with 2 liters of extraction solvent (10% acetic acid:90% iso-butyl alcohol) for 2 min and filtered through fine cloth. Total amount of crude extract was 2,450 ml. The extract was concentrated to near dryness in vacuum by a rotary evaporator at 50 oC and final weight was 94 g. Carotene and anthocyanin content in both the crude extract and pulp were measured. About 91% anthocyanin and 55% carotene were extracted into the crude extract. Gluey concentrated extract could not be further dried to produce a powdery product for a capsule and, thus, a gel-capsule packaging is proposed
to market a final product.
Impacts
Developing new food suplement products by utilizing culls left in the field will enable vegetable growers more economic benefits and make them more competative.
Publications
- No publications reported this period
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Progress 01/01/01 to 12/31/01
Outputs
This year I have been testing about 200 carrot lines for carotene, terpenoids, and sugars. I have selected for high carotene, over 150 ppm for a breeding program of Dr. Leonard Pike. In onions, I continued screenig mild onions from various breeding materials. I have tested over 12,000 bulbs and made selections for pyruvic acid levels below 3.5 unit. I hope new onion variety with extreamly mild flavor would be available within 2 years. This year I included pepper analysis in the program. I had over 200 varieties of peppers including wild species. I have tested viamin C, quercetin, luteolin, and carotenoids. this research will help to develop new pepper varieties with high levels of vitamin C, flavonoid, and carotenes. Analysis of capsaicin is under way.
Impacts
A. CEMICAL ANAYSES:Identifying and measuring health benefit compounds in various vegetables will help Texas producer promote their products for better quality and price. Eventually, this research will enable Texas vegetabel industry become more competative than others without this type of support. We may develop new milder onion cultivars adapted for Texas where the soils are not suitable fro mild onion production. This mild onions might be sold with premium price and would make Texas onion growers more profitable, as compared to current marginal profit. B.TISSUE CULTURE:Current research using haploids and tissue culture technique will shorten breeding cycle significantly and more efficient. Maintaner lines will be identified within a year and a male-sterile & maintainer pairs can be selected quickly. Thus, developing new hybrid onions could be done within 4 to 6 years, rather than nearly 20 years.
Publications
- Yoo, K.S and Pike, L.M. 2001. Determination of background pyruvic acid concentrations in onions, Allium species, and other vegetables. Scientia Horticulturae 89:249-256.
- Lazcano, C.A, Yoo, K.S, Pike, L.M. 2001. A method for measuring anthocyanins after removing carotenes in purple colored carrots. Scientia Horticulturae 90:321-324.
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Progress 01/01/00 to 12/31/00
Outputs
A. CHEMICAL ANALYSES CARROTS: About 300 lines of carrot were tested for carotene, anthocyanins, sugars, and terpenoid content for developing new cultivars. Carotene content varied between 100 and 180 ppm. Anthocyanin is uniquely existing in 'BetaSweet' purple carrot developed by Dr. Leonard Pike team at the Vegetable and Fruit Improvement Center and its content varied between 400 and 900 ppm. Selections were made for uniformly darker colored roots and those selected groups were caged and seeds from them are now growing in thte fields for evaluation. Sugar content ranged between 6 and 8% and there was little variation. Terpenoids are responsible for oily and harsh flavor in carrots and ranged between 3 and 25 ppm. Any carrot with more than 10 ppm terpenoids were rejected in our breeding program. Commercial carrot varieties grown from California and Wisconsin were tested for their quality evaluation. They contained slightly less amounts of carotene, sugars, and
terpenoid, probably because they were harvested immature. ONIONS: I have tested more than 6,000 individual onion bulbs from our breeding lines and commercial cultivars. Some of our advanced lines showed extreamly mild pungency (2 micro moles pyruvic acid)after 3 or 4 generation of screening for low pungency. Our data clearly indicated that breeding for low or high pungency onion is practically possible by using an automated analysis system, which enables us to process 500 samples per day. OTHER VEGETABLES: I have tested 8 kinds of leafy and root vegetables for vitamin C, carotene, flavonoid, and anthocyanin content. Those included swiss chard (green and red), collard, beet, kohlrabi(red and green), kale, and dandelion. After this intial study, more various vegetables will be tested for other chemical compounds for promoting health benefits of these vegetables. B. TISSUE CULTURE For regeneration of haploid plants from various genetic backgrounds of onions, we have cultured more than
100,000 flowers from more than 100 lines and produced around 140 haploid plants. Another 50 haploid plants were regenerated from two F-1 hybrid plants to study color genetic in onion. We produced yellow and red onion plants from the pink mother plants without pollination. Thirty six test crosses were made between male-sterile plants and existing dihaploid plants to test combining ablity and bulb quality. Using these materials, we will try to identify molecular marker linked to the restore gene of male sterility. For this purpose, two F-2 populations, 250 plants of T-3 and 360 of T-5, were made for BSA(Bulk segregant analysis). Currently, we are testing various probes for this marker. We are also planning to study on the inheritance of red color in onion bulbs using the segregating populations.
Impacts
A. CEMICAL ANAYSES:Identifying and measuring health benefit compounds in various vegetables will help Texas producer promote their products for better quality and price. Eventually, this research will enable Texas vegetabel industry become more competative than others without this type of support. We may develop new milder onion cultivars adapted for Texas where the soils are not suitable fro mild onion production. This mild onions might be sold with premium price and would make Texas onion growers more profitable, as compared to current marginal profit. B.TISSUE CULTURE:Current research using haploids and tissue culture technique will shorten breeding cycle significantly and more efficient. Maintaner lines will be identified within a year and a male-sterile & maintainer pairs can be selected quickly. Thus, developing new hybrid onions could be done within 4 to 6 years, rather than nearly 20 years.
Publications
- Yoo, K.S. and Pike. L.M. 2000. Determination of background pyruvic acid concentrations in onions, allium species, and other vegetables. Scientia Horticulturae (in press).
- Lazcano, C.A, Yoo, K.S. and Pike, L.M. 2000. a method for measuring anthocyanins after removing carotenes in purple colored carrots. Scientai Horticulturae (in press).
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