ESI-FT-ICR mass spectra in both ionisation modes, ESI(+) and
ESI(-), were acquired to evaluate the chemical profile of CWsamples as a function of ageing time. When analysing the initial
ambient degradation conditions (an ageing time of between 0
and 6 h), no changes were observed in the chemical profiles of
FT-ICR mass spectra. Fig. 1a and b show the typical ESI(+)
(Fig. 1a) and ESI() FT-ICR (Fig. 1b) mass spectra of aged CW for
a period of 6 h. For the ESI(+)-FT-ICR mass spectra (Fig. 1a), m/z
219.0266 (majority specie) and 399.0897 ions were detected as
potassium adducts ([C6H12O6+K]+ and [C12H24O12+K]+ ions). Their
molecular formulas correspond to fructose and/or glucose, and
sucrose molecules, respectively. Additionally, the accurate m/z values
(219.0266 and 399.0897) are also in agreement with the calculated
m/z values (219.0265 and 399.0899), detected with mass
deviations lower than 1 ppm (0.25 and 0.56 ppm, respectively).
The DBEs of 1 and 2 for fructose/glucose and sucrose molecules
indicate the presence of one (furan and/or pyran) and two (furan
and pyran) rings, respectively. Therefore, accurate mass measurement
can be used for a more robust identification of the chemical
profile of the species present in these fruits.