Quantitative and qualitative studies on the bacteriological quality of Indian white shrimp (Penaeus indicus) stored in dry ice

Indian white shrimp (Penaeus indicus) stored in dry ice at the 1:1 ratio were found to be organoleptically suitable for consumption when they were stored for 24 h without reicing. Shrimp stored in water ice at the 1:1 ratio (as control) were acceptable up to 18 h. Shrimp stored in a combination of dry ice and water ice at the ratio of 1:0.2:0.5 were also found to be acceptable up to 24 h. Total bacterial load ranged from 10(6) to 10(9) cfu g(-1), while total psychrophiles ranged from 10(3) to 10(6) cfu g(-1). Total lactics were found in the levels of 10(2)-10(6) cfu g(-1). H(2)S producers were from 10(3) to 10(5) cfu g(-1). Lowest temperature of -4.8 degrees C was observed in shrimps stored in dry ice at 1:1 ratio. Bacterial flora associated with fresh raw shrimp were Aeromonas, Pseudomonas, Vibrio, Flavobacterium and Serratia. Aeromonas constituted 38% of the flora in raw shrimp. Flavobacterium (43%), Pseudomonas (47%) and Pseudomonas (38%) were the dominant bacterial flora in the shrimp stored in dry ice at 1:1 ratio, in the combination package, and in water ice at 1:1 ratio, respectively.