The mean values of total bacterial, yeast and mould, and
Staphylococcus counts in fresh pineapple slices were found to be in
the range of 102–103 cfu/g (Table 2). There was an increase in TBC,
YMC, and Staphylococcus count of freshly cut pineapple slices after
6 days at ambient storage temperature (Table 3). Coliforms were
not detected. The difference in microbial load between potassium
metabisulfite dipped and freshly cut slices on day 1 of storage was
found to be statistically insignificant (P < 0.05), whereas, osmotic
dehydration was found to decrease the bacterial load. Moreover,
the increase in bacterial load, YMC and Staphylococcus counts of
osmotically dehydrated slices during 6 days of storage was statistically insignificant (P < 0.05). The combination of osmotic dehydration with infrared drying decreased TBC, YMC and
Staphylococcus counts which remained constant up to 6 days of
storage (Table 2). Most bacteria fail to grow at aw of less than 0.82
(Ledward, 1981). Intermediate moisture products in which aw is
reduced to inhibit microbial growth can be stored for extended
periods under ambient conditions (Ledward, 1981). However,
reduction of aw alone could not bring counts below the detection
limit and so, mould growth was observed in samples during storage