Location: Food Quality Laboratory
2011 Annual Report
Next, intraspecific crosses will be made between peppers with high flavor/nutritional quality and commercial bell pepper breeding lines. Resulting F1 families will be selfed to create F2 mapping populations and segregating F2 populations will be selfed to create F3 populations. Fruit from F3 plants will be phenotyped for flavor quality and parental lines and segregating F2 populations will be genotyped using SNP marker technology: quantitative trait loci for flavor quality will be identified. Intraspecific crosses will also be made between M. sieversii with unique flavors and a domesticated apple cultivar (Gala) and resulting F1 families evaluated for flavor quality and further backcrossed with ‘Gala’ to create uniquely flavored, high quality breeding lines.
Concurrent with flavor quality evaluations, flavorful fruit from non-treated apple, blueberry and pepper genotypes and those from pre-harvest foliar potassium fertilizations and post-harvest heat, light and high oxygen storage treatments will be evaluated for antioxidant activities (i.e., oxygen radical absorbance capacity, hydroxyl radical and superoxide radical scavenging capacity and DPPH activity), superoxide dismutase activity, vitamins (provitamin A, B9, C, E and K1) and other phytonutrients/minerals using established in-house procotols.
Fruit from select accessions/cultivars with increased post-harvest nutritional and/or analytical quality attributes will be evaluated by consumer panels for acceptability and intensity of sweetness, sourness, specific flavors depending on fruit type and texture and for acceptability of overall eating quality. Fruit from uniquely flavored, high nutrient pepper accessions will be further evaluated for the effects of fresh cutting on maintenance of flavor and nutritional quality and shelf stability.
Flat-leaf varieties of spinach have higher levels of vitamins A, B9, E, and K and carotenoids. Higher vitamin and carotenoid levels were also found in younger leaves, plants grown in clay soils, and plantings established under long day-lengths. This means that enhancement of spinach nutritional quality and marketability can be achieved at the grower level through cultivar selection, site selection, planting date, and targeting harvesting around leaf age.
New varieties of fruits and vegetables are needed to combat plant diseases and to enhance produce quality and shelf stability. Scientists from Beltsville, MD, worked closely with geneticists from Salinas, CA, in developing new Verticillium wilt-resistant lettuce varieties and evaluating their quality and storage life, especially after cross-country shipment. This collaborative research has led to the development and release of two new disease resistant lettuce varieties with improved quality and shelf stability. Additional breeding lines are currently being evaluated for improved shelf stability for packaged fresh-cut products and disease resistance.
Assay parameters for optimizing melon fruit phospholipase D (PLD) activity were developed. PLD activity is a regulator of fruit softening and was found to be controlled by pH, cofactor calcium and substrate levels, reaction time and temperature. An in-depth evaluation of rapid versus slow softening melon cultivars is confirming the optimal assay parameters prior to down-regulating PLD activity in genetically modified melon flesh.
Wang, C.Y., Chen, H., Jin, P., Gao, H. 2010. Maintaining quality of litchi fruit with acidified calcium sulfate. Journal of Agricultural and Food Chemistry. 58:8658-8666.
Hayes, R.J., Maruthachalam, K., Vallad, G.E., Klosterman, S.J., Simko, I., Luo, Y., Subbarao, K.V. 2011. Iceberg lettuce breeding lines with resistance to Verticillium wilt caused by race 1 isolates of Verticillium dahliae. HortScience. 46(3):501-504.
Jin, P., Wang, S.Y., Wang, C.Y., Zheng, Y. 2011. Effect of cultural system and storage temperature on antioxidant capacity and phenolic compounds in strawberries. Food Chemistry. 124:262-270.
Fleshman, M.K., Lester, G.E., Riedl, K.M., Harrison, E.H., Kopec, R.C., S, N., Schwartz, S.J. 2011. Carotene and novel apocarotenoid concentrations in orange-fleshed Cucumis melo melons: determinations of beta-carotene bioaccessability and bioavailability. Journal of Agricultural and Food Chemistry. 59:4448-4454.
Luo, Y., Lu, S., Zhou, B., Feng, H. 2011. Dual effectiveness of sodium chlorite for enzymatic browning inhibition and Escherichia coli inactivation on fresh-cut apples. Journal of Food Science and Technology. 44:1621-1625.