3.5. Microbial analyses
Effect of g-irradiation and frozen storage (?20 ?C) on the microbial quality of prawns are shown in Table 3. Irradiation with total aerobic bacterial counts by 1.77e3.06 log units in fresh water prawns and by 1.52e3.28 log units in tiger prawns. The total mould count was reduced by 1.26e2.45 log units and 0.58e1.72 log units in fresh water prawn and tiger prawn respectively. The counts became non detectable at 5 kG and above. The microbial quality of the irradiated samples was maintained during frozen storage of 56 days. Coliforms were particularly sensitive and were eliminated at 1.5 kG. Salmonella was detected in the control samples of tiger prawn but not in the irradiated samples above 0.5 kGy during 56 days of storage. Salmonella could not be detected in the samples of fresh water prawn.