During the sublimation period of FD and
FMVD processes (Fresh, FD 1 h, FD 3 h, and FD 5 h), the content
of mannitol in samples increased from 121 to 147 mg/g. There
was a possibility that an increase in the temperature of samples
with the progress of FD led to the activation of enzymes, prompting
the metabolism of macromolecule sugars, which could be the main
reason for mannitol content increase. Comparable results could be
found in the study by Tsai et al. (2007).