The results of the bacteriological analysis for samples are presented
in Fig. 3. Reduction of log10cfu was observed in irradiated
samples and the counts increased most rapidly in control samples.
At the beginning of the storage, it was found that increasing the level
of irradiation dose from 0.5, 1, 2 and 3 kGy resulted in a significantly
decrease in the values of total viable counts (TVC) during
the storage period. The initial TVC in the control salmon fish samples
was 4.7 log10 cfu/g, and quickly reached 9.2 log10 cfu/g at the
end of storage period, whereas, it was only 5.5 log10 cfu/g for
3 kGy irradiated samples. The above result indicated that irradiation
was effective in inhibiting spoilage bacteria growth and
extending the storage life of the salmon fish samples. Although
Paari et al. (2012) reported that 2.7 ± 0.1 log10cfu/g bacteria were
still existed for 10 kGy irradiated goat fish samples using gamma
irradiation, it is unacceptable to irradiate the salmon fish samples
because of the ‘colour fading’ and ‘irradiation odour’ according to
the sensory assessment.