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United States Department of Agriculture

Agricultural Research Service

Research Project: PHYSIOLOGICAL AND GENETIC BASIS OF POSTHARVEST QUALITY AND PHYTONUTRIENT CONTENT OF FRUITS AND VEGETABLES
2007 Annual Report


1a.Objectives (from AD-416)
The overall objective of this project is to develop value-added products from fruits and vegetables, especially those containing phytonutrients. Anthocyanins and carotenoids are plant pigments that contribute to fruit quality and are also phytonutrients, and will be one objective of this project. Other objectives include selection and breeding of watermelon for enhanced lycopene content and modification of fruit quality for new market niches.


1b.Approach (from AD-416)
Experiments to determine the physiology and develop technology necessary to extend the shelf life, marketability, and phytonutrient content of highly perishable fruits will be conducted. Enhancement of watermelon germplasm for market traits will be done using classical breeding techniques and exploration of the carotenoid path in watermelon will be done using molecular methodology. Food-grade formulations for extraction and stabilization of aqueous-based lycopene for extended shelf will be developed.


4.Accomplishments
Watermelon Improves Health Status of Diabetic Fatty Rats: Watermelon contains lycopene, a pigment with antioxidant properties, and citrulline, a non-essential amino acid with vasodilation properties. Scientists at the South Central Agricultural Research Laboratory in Lane, OK, in cooperation with researchers at Texas A&M, determined the effectiveness of watermelon in ameliorating cardiovascular events in Zucker diabetic fatty rats. Animals were fed diets supplemented with watermelon pomace (residue from watermelon juice), lycopene, pectin, or arginine/citrulline. Rats fed with watermelon or arginine/citrulline had reduced blood glucose and weight gain, and better aortic flexibility than other treatments. These results indicate that amino acids in watermelon have promise in controlling obesity in humans, and that the pomace may be useful for value-added products. (NP306, Component 1)

Lycopene Increased by Grafting in Watermelons: Cucurbits, especially watermelon, have been grafted for many years in Asia to avoid soil-borne diseases. There is increased interest in vegetable grafting in the U.S. as soil fumigants become limited. Rootstocks have an important influence on the growth and yield of the grafted scion, but quality effects are less well characterized. Scientists at the South Central Agricultural Research Laboratory in Lane, OK, in cooperation with seed company breeders, found that watermelon lycopene could be increased 20 to 80% in fruit from grafted plants, depending on rootstock, scion, and production environment. Lycopene, the red pigment found in watermelon and tomatoes, is a natural food colorant and antioxidant. These results are important in order to maximize lycopene yield and further explore use of grafting as an alternative production strategy. (NP306, Component 2)

Lycopene Formation in Watermelon Chromoplasts: Carotenoids are pigments that give fruit color, protect cells from photoxidation, and are formed in chloroplasts, or chromoplasts, that are microscopic parts of the cell. The arrangement of carotenoids in the chromoplast affects the stability and extraction difficulty of pigments. Carotenoids are most soluble in organic solvents, making removal of solvents after extraction tedious and expensive if carotenoids are used for food products. A scientist at the South Central Agricultural Research Laboratory in Lane, OK, found that watermelon lycopene has a J-type chiral arrangement inside the chromoplast membrane. This type of arrangement allowed binding of a detergent that greatly increased water solubility of the chromoplast. This accomplishment is an important step in advancing economic lycopene extraction for food use. (NP306, Component 3)


5.Significant Activities that Support Special Target Populations
a. Scientists participated in extension tours, field days, and agricultural conferences where technology was transferred to primarily small acreage growers.

b. Scientists actively interacted with local, female, small scale organic grower to help with marketing and production issues in fruit and vegetable production.


6.Technology Transfer

Number of new CRADAs and MTAs2
Number of active CRADAs and MTAs1
Number of non-peer reviewed presentations and proceedings22
Number of newspaper articles and other presentations for non-science audiences32

Review Publications
Perkins Veazie, P.M., Collins, J.K., Clevidence, B.A., Wu, G. 2007. Watermelons and health. Acta Horticulturae. 731:121-127.

Perkins Veazie, P.M., Roberts, W., Collins, J.K. 2006. Lycopene content among organically produced tomatoes. Journal of Vegetable Science. 12(4):93-106. .

Davis, A.R., Webber III, C.L., Perkins Veazie, P.M., Collins, J.K. 2006. Impact of cultivar and production practices on yield and phytonutrient content of organically grown watermelon. Journal of Vegetable Science. 12(4):83-91.

Collins, J.K., Wu, G., Perkins Veazie, P.M., Spears, K., Claypool, P.L., Baker, R.A., Clevidence, B.A. 2007. Watermelon consumption increases plasma arginine concentrations in adults. Nutrition. 23:261-266.

Collins, J.K., Davis, A.R., Adams, A.L., Maness, N., Perkins Veazie, P.M. 2006. Consumer acceptability of low sugar watermelon sweetened with non-calorie sweetener by a Native American community. International Journal of Food Sciences and Nutrition. 57:(5/6):363-368.

Levi, A., Davis, A.R., Hernandez, A., Wechter, W.P., Thimmapuram, J. 2006. Genes Expressed during the Development and Ripening of Watermelon Fruit. Plant Cell Reports 25:1233-1245.

Fish, W.W. 2006. Interaction of sodium dodecyl sulfate with watermelon chromoplasts and examination of the organization of lycopene within the chromoplasts. Journal of Agricultural and Food Chemistry. 54(21):8294-8300.

Fish, W.W. 2007. Novel procedure for the extraction and concentration of carotenoid-containing chromoplasts from selected plant systems. Journal of Agricultural and Food Chemistry. 55:1486-1490.

Davis, A.R., Collins, J., Fish, W.W., Tadmor, Y.K., Webber III, C.L., Perkins Veazie, P.M. 2007. Rapid method for total carotenoid detection in canary yellow-fleshed watermelon. Journal of Food Science. 72(5):S319-S323.

Last Modified: 4/19/2014
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