| MS Description
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Sample extraction<br />
Crushed and … Sample extraction<br />
Crushed and frozen samples (10 g) were resuspended in 50 mL of MeOH, including internal standards for standardization of peak areas, and centrifuged (16,000 × g, 3 min, 4°C). Supernatants were dispensed for each analysis as follows: 0.5 mL for ionic metabolites, 1 mL for neutral metabolites, 1 mL for sugars, and 47.5 mL for plant hormones. Because of the small amounts of pear fruit samples obtained in the early periods (2WBB, 1WBB, and B), the initial amounts of these samples were 1 g, extracted in 20 mL of MeOH, and were separately used for each analysis as described above. The residues were subsequently used for starch analysis.<br />
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Metabolite profiling using CE-TOF MS<br />
For the analysis of ionic metabolites, hydrophobic and high molecular weight compounds were removed by the preparative processes of liquid–liquid separation using chloroform and water, and ultrafiltration using a 5 kDa cutoff filter, respectively, prior to the metabolomic analyses. Comprehensive analysis of ionic metabolites using CE-TOF MS was performed as previously reported. F MS was performed as previously reported.
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