Organoleptic, biochemical and microbiological qualities of Shrimp (Penaeus monodon) at each point of marketing channel in Satkhira district of Bangladesh

Abstract

Investigation was carried out on the quality aspects of shrimp (Penaeus monodon) in the distribution channel of Satkhira district in Bangladesh during September to November 2004. Organoleptic, biochemical and microbiological (SPC, TC, FC, Salmonella sp. and Vibrio sp.) qualities were assessed at each major point of the distribution channel (Gher, Agent, Depot, and Processing Plant). Quality changes were studied during normal practice (NP) and controlled study (CS). For normal practice, no ice was used, but in the controlled study, a 1:1 icing ratio was maintained during preservation and transportation of the shrimp. In both cases, shrimp was acceptable organoleptically at all distribution points. The average organoleptic score ranged between 6.27 and 8.92 in NP and 7.61 and 8.97 in CS. The TVB-N content varied between 2.56 mg N/100 g and 6.21 mgN/100 g in NP and 2.32 mgN/100 g and 5.87 mgN/100 g in CS. The lowest amount of TVB-N was found in Gher and the highest in the Processing Plant. TMA-N value increased slightly from Gher to Processing Plant, and the value ranged between 2.43 and 3.62 mgN/100 g in NP and 2.65 and 3.73 mgN/100 g in CS. The highest SPC was found in the Processing Plant in both practices, which were 5.93 cfu/g (log₁₀ value) in NP and 5.91 cfu/g (log₁₀ value) in CS. Total coliform counts varied between 27 and 53 MPN/g for shrimp collected under normal practice, while relatively lower total coliform counts were observed in shrimp collected under controlled study (15 to 35 MPN/g). Faecal coliform was present at each point of the distribution channel. Average faecal coliform counts varied between 4.1 and 7.4 in NP and 4.8 and 6.3 in CS. It was absent in the Processing Plant, as observed in the controlled study. However, the counts were within the acceptable limit of 10 MPN/g. Salmonella and Vibrio sp. were not detected at any point of the distribution channel in either case.