Collect chemical (2X50ml) samples of fresh juice, cider, or vinegar made from apple varieties in the orchards, if available. Samples collected in North America will be sent to BRIT, and in Europe to University of Gastronomic Sciences (UGS), Italy before being forwarded in bulk for analysis at the University of British Columbia (UBC). The 50ml aliquots will be put in sterile plastic, screw-top, centrifuge vials. The product labels and country of origin will be recorded with each sample and matched with plant voucher specimens, (note that often managers are selling juice, cider, or vinegar from their own orchards so samples will be purchased).
The phytochemical profiles (Cao et al. 2006, Le et al. 2010, Murch et al. 2009) will be determined using the UPLC-(ToF)MS for analyses of the known phytochemicals. Comparative metabolomic/metabonomic analyses will be undertaken to understand the differences. Metabolomics is the quantitative measurement of all low molecular mass metabolites in tissues at a specific time under specific environmental conditions (Feihn 2002). Metabonomics (Lindon et al. 2003) are the changing patterns of metabolites over time. High-performance mass spectrometry with chromatographic separations permits detection of chemical complexity in biological samples and information about the chemical nature of each compound. Principle Component Analysis (PCA) is used to identify characteristic compounds. Groups of compounds can then be identified from a single known compound in the extraction and transformation of the data with standard values allowing for the generation of families of metabolites. This approach has been used in previous studies to identify the characteristic phytochemical differences between species of Scutellaria (Cole 2007, Murch et al. 2010) and to identify the differences in the chemical profile of merlot grapes and wines (Le et al. 2010).
Metabolomic analysis will generate “fingerprints” for specific varieties of apples, as well as indications of responses that those varieties are having to environmental conditions (not the specific cause of the responses, just that they are having specific metabolic responses). This will allow for comparisons of apple varieties in different locations that have different names and even morphologies, but may be chemically (metabolically) the same. We will be able to identify patterns of responses to environments across large areas of space when the same variety is examined and also may see similar or different responses from different varieties being grown within the same orchard. These patterns will contribute to a dynamic understanding of the responses that humans are tracking because people are selecting for fruit and cider as key products from these orchards.