1a. Objectives (from AD-416):
1. Identify volatile compounds that accumulate during CA storage. 2. Characterize volatile compound dynamics during storage in atmospheres that induce low O2 and/or high CO2 injury. 3. Determine if recognition of changes in volatile compound production during low O2 or high CO2 stress has utility for CA system management. 4. Develop sampling protocols to enable detection of biomarkers for scald and other disorders.
1b. Approach (from AD-416):
An untargeted analysis of volatile compounds in controlled atmosphere chambers and rooms will be conducted using current analytical technologies. Impacts on volatile production from pre-storage treatments (DPA, SmartFresh), as well as timing and duration of O2 and/or CO2 stress will be evaluated. Analyses will primarily be conducted using gas chromatography/mass spectrometry which provides highly informative qualitative and quantitative results with high sensitivity.
3. Progress Report:
This serves as the final report for project 5350-43000-006-11T which expired 4/30/13. This project relates to objective 2 of the associated in-house project which seeks to identify factors that influence postharvest fruit quality and development of market limiting physiological disorders. The project’s objective is to characterize volatile compounds produced by apple fruit during storage in controlled atmospheres known to induce physiological disorders. During the life of the project, ARS scientists at the Tree Fruit Research Laboratory in Wenatchee, Washington, confirmed identification of volatile compounds for which ethanol is required for production are produced in much larger amounts by Delicious apples during storage in 0.3% oxygen compared to fruit stored in 0.8 or 1.6% oxygen. While general trends were similar over the 3 years of the study, compound production differed from year to year, a finding that would be an important consideration when using volatile compound analysis to monitor fruit health during storage. Volatile compounds for which methanol is required for production are produced in larger amounts by Fuji apples stored in 5% carbon dioxide (with 1% oxygen), the only carbon dioxide concentration in which fruit injury developed. The results indicate non-invasive assessment of apple fruit volatile accumulation may provide a means to monitor fruit condition during controlled atmosphere storage.