Food Chemistry, Nutrition and Safety

Biography

Biography: Motaher Hossain

Abstract

The present study was conducted to assess the comparative bacteriological parameters of Rui (Labeo rohita), Mrigal (Cirrhinus cirrhosus) and Kalibaus (Labeo calbasu) collected from Hakaluki haor of Bangladesh. Sixty three (63) samples for each of the species of Rui, Mrigal and Kalibaus fish was collected from three fishing points of Hakaluki haor in four seasons (monsoon, post-monsoon, winter and pre-monsoon) from May-2017 to January-2019.The methodology was designed to determine Total Viable Count (TVC), Total Coliform Count (TCC), and the prevalence of Escherichia coli, Salmonella spp. and Vibrio spp. Results of the study revealed that, the higher bacterial load was observed in Kalibaus than Rui and Mrigal in all study seasons. In Rui TVC (Log CFU/g ± SD) was 5.565±.091, 5.404±0.1, 5.126±0.22 and5.366±0.2, in Mrigal5.613±0.069, 5.571±0.07, 5.293±0.181 and 5.682±0.077 whereas, in Kalibaus TVC was 5.8±0.14, 5.714±0.11, 5.552±0.056 and 5.544±0.067in monsoon, post-monsoon, winter and pre-monsoon respectively. As indicator organisms total coliform count (TCC) MPN/g of Rui were 50, 49, 23 and 47, in Mrigal 58, 62, 33 and 63, where in Kalibaus TCC were 85, 74, 55 and 86 in monsoon, post-monsoon, winter and pre-monsoon respectively. Pathogenic bacteria such as Escherichia coli, Salmonella spp. and Vibrio spp. was also isolated from all  fish in all study seasons. In monsoon percentage of these isolated bacteria was 44%, 16% and 5% in Rui, 50%, 22% and 11% in Mrigal, 72%, 33% and 27% in Kalibaus. In post-monsoon percentage of these isolated bacteria was 39%, 22% and 11% in Rui, 61%, 33% and 0% in Mrigal, 61%, 33% and 33% found in Kalibaus. In winter percentage of these isolated bacteria was 28%, 22% and 0% in Rui, 44%, 33% and 16%inMrigal, 55%, 22% and 22% found in Kalibaus. In Pre-monsoon percentage of these isolated bacteria was 55.55%, 33.33% and 22.22% in Rui, 77%, 44% and 33% in Mrigal where 78%, 55% and 44% in Kalibaus. Results of this study indicated that the prevalence of pathogenic bacteria was lower in Rui than in Mrigal and Kalibaus in all study seasons. Bacterial load and occurrence of E. coli, Salmonella spp. and Vibrio spp. in all fish samples indicate the contamination which may be connected to environmental conditions of the harvesting area and post-harvest handling of fish.

Chemical Study

The present study was conducted to investigate the heavy metal concentration in water and Indian Major Carps collected from Hakaluki haor of Bangladesh. Three important fish species, viz., Labeo rohita, Cirrhinus cirrhosus and Labeo calbasu together with water samples were analyzed for heavy metals concentrations (Pb, Cr and Cd). To obtain the objectives of the study, total ninety six (96) samples were collected from three fishing points of Hakaluki haor in four seasons (monsoon, post monsoon, winter and pre-monsoon) from June, 2017 to May, 2018. The levels of heavy metals were measured by atomic absorption spectrophotometry after digestion of the samples. Result of the studied samples revealed that, there were great variations among heavy metals in water and fish species. Heavy metals concentration was found higher in fish species than respective areas water which might be due to the food source of the fish. L. rohita accumulated highest levels of Pb, C. cirrhosus accumulated highest levels of Cr, whilst highest levels of Cd were detected in L. calbasu. The decreasing trend of metals were observed in water and fish species as Pb > Cr > Cd. The heavy metal concentrations were found in water varied for Pb: 0.039-0.275, Cr: 0.001-0.039 and Cd: 0.00 (BDL)-0.009 mgL^-1, whilst among the fish species in L. rohita varied for Pb: 0.093-1.190, Cr: 0.001-0.357 and Cd: 0.00 (BDL)-0.011 µgg^-1, in C. cirrhosus varied for Pb: 0.145-1.189, Cr: 0.001-0.418, Cd:  0.00 (BDL)-0.004 µgg^-1, and in L. calbasu varied for Pb: 0.095-0.690, Cr: 0.001-0.467 and Cd: 0.00 (BDL)-0.0012 µgg^-1. Very trace amount of Cd were identified both in water and fish species and most of the cases Cd levels were found below the detection limit. During monsoon season higher content of Pb and Cr was observed both in fish and water samples in compare to other seasons. Out of three estimated heavy metals, Cr and Cd concentration in water and fish species were within the acceptable limit in all seasons permitted by WHO, EC, EU, FIQC and FAO. But the level of Pb in water and fish species has crossed the permissible limit given by WHO, FIQC and EC almost in all seasons. Result of this study indicating that Hakaluki haor is partially a heavy metal polluted haor and the water and fishes may be not fully safe for human health and ecosystem. This study recommended that continuous monitoring and proper management action should be taken to assure food safety and protect the public health and to reduce environmental risks.