Quality of Shrimp (Penaeus monodon) at Different Points of Distribution Channel in Bagerhat District

Abstract

The present study was conducted to assess the quality of Penaeus monodon at each point of the distribution channel under normal practices (NP). The study area included Bagerhat District, and the points of the distribution channel were Gher (pond), Depot, Agent, and Processing Plant. Another set of experiments was conducted using ice at a ratio of 1:1 (ice: shrimp) at all points of the distribution channel and was referred to as the controlled study (CS). The results of the controlled study were compared with those of normal practice. Quality assessment included organoleptic, biochemical [trimethylamine nitrogen (TMA-N) and total volatile base nitrogen (TVB-N)], and microbiological [Standard Plate Count (SPC), total coliform, faecal coliform, Salmonella spp., and Vibrio cholerae] parameters. Overall, the organoleptic acceptability scores ranged from highly acceptable to moderately acceptable for shrimp transported from Gher to Processing Plant under normal practice. The scores were 8.8, 5.47, 6.67, and 6.33 at Gher, Depot, Agent, and Processing Plant, respectively, on a scale of 10. The controlled study indicated relatively better scores and higher quality of shrimp based on organoleptic evaluation. TVB-N values of shrimp at Gher and Agent were very low under normal practice (2.40 and 5.32 mg N/100 g, respectively). However, these values increased sharply to 15.35 and 8.13 mg N/100 g at Depot and Processing Plant, respectively. In the controlled study, TVB-N values did not vary greatly among the different points, although the value at Depot (7.85 mg N/100 g) was considerably lower than that observed under normal practice. In both studies, TVB-N values remained within the acceptable limit of 30–40 mg N/100 g. The highest TMA-N value was found at Depot (10.75 mg N/100 g) in the controlled study. However, all TMA-N values in both experiments were low and remained within the acceptable range of 12–15 mg N/100 g. The maximum Standard Plate Count (SPC) values under normal practice were 0.5 × 10⁵, 1.2 × 10⁵, 1.3 × 10⁵, and 0.36 × 10⁵ CFU/g at Gher, Depot, Agent, and Processing Plant, respectively. These values differed from those observed in the controlled study; however, the differences were within one log cycle and remained below the acceptable limit of 10⁶ CFU/g. Total coliform counts under the controlled study ranged from 3 to 28 MPN/g. Relatively higher total coliform counts were observed under normal practice, with values of 53 MPN/g at Gher, 20 MPN/g at Depot, 43 MPN/g at Agent, and 28 MPN/g at Processing Plant. All values were lower than the recommended limit of 100 MPN/g. In most cases, faecal coliform (FC) was not detected in either experiment. The highest FC count was found at Gher (15 MPN/g) under normal practice, which was slightly higher than the acceptable limit of 10 MPN/g. Salmonella spp. and Vibrio cholerae were not detected in any samples from either the controlled study or normal practice.