Peaches canned in enamel-coated cans lost 30–43%
WW of TPs after 3 months of storage at room
temperature (Table 15).46 The authors did not assay
the syrup in this study, but in a subsequent study they
reported that the procyanidins lost during canning had
actually migrated to the syrup.48 Chaovanalikit and
Wrolstad47 found similar results for cherries canned
in enamel-coated cans (Table 15). Significant losses
of anthocyanins were found in canned cherries and
their syrup stored for 5 months at room temperature.
Slight but insignificant decreases in TPs, however,
were found after 5 months of storage at both chilled
and room temperatures. The level of TPs in the
cherries and syrup was still higher than that in fresh
cherries, however, owing to the apparent increases
during thermal processing.
Some authors have suggested that the degradation
of phenolic compounds during canned storage may be
dependent on the type of can used. Tin-plated cans
can sacrifice tin to compete for available oxygen, thus
sparing some of the phenolic compounds.46 Research
is needed to determine if this is a viable method
for increasing retention rates of phenolic compounds
during canned storage.