2007 Annual Report 1a.Objectives (from AD-416) To determine the impact of citrus greening disease (Huanglongbing (HLB) on the quality of juice produce from infected trees. Meeting this objective will increase our understanding of how citrus greening affects citrus juice quality and will aid in establishing strategies to deal with fruit produced in infected groves. 1b.Approach (from AD-416) Cooperator will provide fruit and/or juice samples from greening infected and healthy citrus trees which ARS will analyze samples for standard juice quality parameters, chemical composition, and sensory characteristics. The juice samples will be determined using refractometry, sugar composition will be determined using high pressure liquid chromatography with evaporative light scattering detection. Acidity will be determined by titration and sodium hydroxide to a pHof 8.2. Juice color will be measured using the Gregtag-MacBeth colorimeter. Flavonoids will be determined by high pressure liquid chromatography/mass spectroscopy. Aroma volatiles will be determined using gas chromatography and electronic nose technology. Sensory analysis will be conducted using both consumer and trained panelists. 3.Progress Report This report documents research conducted under a nonfunded cooperative agreement between ARS and United States Sugar Corporation. Additional details of research can be found in the report for the in-house associated project 6618-21000-012-OOD, Genetic Improvement of Citrus. Fruit samples were collected from commercial groves from trees positive or negative for HLB. Hamlin, MidSweet and Valencia oranges were evaluated. Fruit were juiced and the juice was analyzed for color, soluble solids, titratable acidity, and flavor volatiles. Juice samples were also subjected to sensory analysis to determine if panelists could distinguish juice from healthy or HLB-infected trees.