Location: Food Quality Laboratory
2010 Annual Report
Objective 1: Evaluate the effects of pre-harvest production and post-harvest processing and storage treatments on fruit flavor maintenance and/or enhancement in diverse accessions and breeding lines of Capsicum pepper, Malus serversii apple and blueberries; determine underlying molecular mechanisms controlling flavor quality.
• Sub-objective 1A. Evaluate fresh produce for chemical constituents, sensory attributes and underlying molecular mechanisms that contribute to fruit flavor quality in diverse accessions of Capsicum pepper, Malus serversii apple and rabbiteye blueberry.
• Sub-objective 1B. Determine the impact that selective plant breeding and post-harvest fresh-cut processing and storage have on fruit flavor maintenance and/or enhancement.
Objective 2: Evaluate the effects of pre-harvest production and post-harvest processing and storage treatments with potential to increase post-harvest concentrations of phytonutrients and antioxidant capacity in fruit of selected Capsicum species, Malus serversii apple and blueberries, focusing on pre-harvest foliar potassium fertilization, post-harvest heat and high-oxygen storage treatments.
• Sub-objective 2A. Evaluate the potential for pre-harvest foliar potassium fertilization, post-harvest treatment with heat and high oxygen storage to maintain or increase antioxidant capacity, antioxidant and/or other phytonutrient concentrations of fruit.
• Sub-objective 2B. Determine the effects of pre- and post-harvest treatment strategies that increase or aid retention of antioxidant capacity or phytonutrient concentrations on flavor quality of fruit from selected genotypes.
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.