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

Abstract

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 2S producers were from 10 3 to 10 5 cfu g - 1 . Lowest temperature of - 4.8 ∘ 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.