Major fungal species that attacked trimmed
sweet corn cobs during storage and shelf life, were
Alternaria alternata (Fr.) Keissler, Fusarium
moniliforme Sheldon, and Mucor hiemalis Wehmer,
in agreement with previous report of Barkai-
Golan (1981). In addition to fungal pathogens,
bacterial and yeast species were also present on
spoiled cobs.
The most severe microbial spoilage was on cobs
sealed in perforated Cryovac SM60M film, either
within nested packages or alone (Fig. 3). Condensed
water accumulated in retail trays packaged
in this perforated polyolefin. The lowest fungal
growth was observed within retail packs made of
the Xtend film. This film treatment also resulted
in the highest CO2 level in the in-package atmosphere
shown in Fig. 2. However, after transfer to
higher temperatures during the shelf life period
the corn in these retail packages developed a
distinct off-odor, reflected in high concentrations
of ethanol and acetaldehyde vapors in the
headspace (Fig. 3). Similar levels of fermentation
volatiles, but more severe decay, were detected in
regular PVC-wrapped trays. It should be noted
that accumulation of ethanol in retail PVCwrapped
trays varied by experiments and, for
example, in the experiment associated with Fig. 1,
was less than half that shown in Fig. 3.
Storage in PVCXtend nested packages allowed
a combination of reduced microbial
spoilage with low accumulation of fermentation
products. The levels of ethanol and acetaldehyde
were significantly lower in nested packages as
compared to the same kinds of retail packages
(PVC or SM60M) used alone (Fig. 3), provided
the liners were open during the shelf life period.