The Carotenoid Project:
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Current Projects:
2003-2004 Spinach Feeding Trial Cooking Spinach Dishes for our Feeding Study Research Publications:
Kale Carotenoids Remain Stable while Flavor Compounds Respond to Changes in Sulfur Fertility. Variability in Elemental Accumulations Among Leafy Brassica oleracea Cultivars and Selections. Variation in lutein, B-carotene, and chlorophyll concentrations among Brassica oleracea cultigens and seasons. Nitrogen Concentration Affects Nutrient and Carotenoid Accumulation in Parsley. Presented Posters:
Grant Descriptions:
Assessing lutein bioavailability from nutritionally-enhanced green leafy vegetable crops. University of New Hampshire, USDA-CSREES-NRI-IFAFS $800,000.00; 48 months (beginning Sept. 2001)
Lutein and zeaxanthin are xanthophyll carotenoids important to the photosynthetic processes of green plants. They may also serve an important biological function as macular pigment in human retinas. Research has shown macular pigment levels to be directly related to dietary intake of fruit and vegetables, and diets rich in green leafy vegetables may protect against aging eye diseases such as cataract and age-related macular degeneration. Enhancing lutein and zeaxanthin in dietary vegetables may therefore reduce the risk and progression of aging eye disease, thus saving millions of dollars in related health care costs. Green leafy vegetables are major sources of these compounds in the diet, but the extent of environmental and genetic influences on carotenoid biosynthesis within these plants is not known. The goals of this project are to enhance carotenoid content of Brassica and Spinacia vegetable crops and predict the related health outcome for the consumer.
This collaborative project will integrate traditional plant physiology with nutritional analysis, effectively linking crop production practices with bioavailability assessment. Plant production methods will be designed to select for and enhance lutein biosynthesis in green leafy vegetable crops. Simultaneously, the determinants of macular pigment density will be investigated, specifically bioavailability of lutein from green leafy vegetables as a source of macular pigment. The lutein-rich crops will be compared to conventional supplemental sources of lutein to determine bioavailability. Information will then be disseminated to the public stakeholders in NH and NE in collaboration with the UNH Cooperative Extension program. The influence of environmental growing conditions on carotenoid accumulation in vegetable crops.
The University of New Hampshire, USDA-CSREES-NRI $19,503.00; 1 year
The goal of our research program is to enhance the phytonutrient content of green leafy Brassica and Spinacia vegetable crops, and thus make them more nutritious. Green leafy vegetables are a rich in lutein and zeaxanthin and provide major sources of carotenoids in human diets. These xanthophyll carotenoids may serve an important biological function as macular pigment (MP) in human retinas. Diets rich in green leafy vegetables may protect against aging eye diseases such as cataract and age-related macular degeneration. Enhancing the xanthophylls in dietary vegetable sources may therefore reduce the risk and progression of aging eye disease, thus saving millions of dollars in health care cost and improving the quality of life for aging adults. Green leafy vegetables are major sources of these compounds in the diet, but the extent of environmental and genetic influences on plant carotenoid biosynthesis is not known.
Experiments will concentrate on the effects of environmental variables, such as fertility, light, and temperature, and genetic variables on the carotenoid concentrations of cultivated green leafy vegetable crops. Carotenoids are thermally unstable and will degrade at high temperatures. Lyophilization is the common recommendation for sample preparation and preservation prior to analysis. A freeze dryer system equipped with a refrigerated drying tray compartment will be needed to preserve carotenoid compounds for HPLC analysis.
The information generated by our research program will help horticultural producers select the best management practices that have been shown to increase essential lutein in green leafy vegetable crops, and thus make them more nutritious.
HPLC separation and identification of plant-derived carotenoid isomers using a polymeric C30 column.
The University of Tennessee, UT Professional Development Grant $4,875.00; 1 year
Plants provide the primary sources of carotenoid compounds in the diet, which provide antioxidant and disease-preventing properties beneficial for human health. Environmental and genetic factors will influence the total accumulation of lutein and beta-carotene carotenoids in plants and research is underway to determine the feasibility of carotenoid enhancement in these crops. Changes in carotenoid chemical structures can occur in plants under different conditions and these changes can affect dietary absorption patterns and antioxidant functions. Funding from the awards program will allow for the identification of isomeric changes in plant carotenoids in response to different environmental growing conditions. This proposal outlines the rationale for requesting funds for the purchase of a polymeric C30 HPLC column and the necessary authentic carotenoid analytical standards for construction of libraries that will be used in future research. Information generated from this project will help us optimize the efficiency of our plant carotenoid enhancement program.
High performance liquid chromatography (HPLC) analysis is the accepted means of separating and quantifying carotenoid compounds in food sources. Previously, our program utilized a reverse-phase C18 column/separation procedure routinely performed at the USDA Food Composition Laboratory in Beltsville, MD. Accurate determination of carotenoid isomers in plant tissues now utilizes a polymeric C30 column in reverse-phase liquid chromatography. We will purchase a C30 column for an existing HPLC system for a more detailed analysis of our plant tissues. Analytical standards of carotenoid compounds and isomers are commercially available (Carotenature, Lupsingen, Switzerland) and will be needed to develop appropriate spectral libraries for photodiode array (PDA) and mass spectral (MS) detection.
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