Birie Solomon, Mingist Minwyelet, Kibret Mulugeta, Atlog Tadlo Yitayew, Geremew Hirut, Getnet Banchiamlak, Mequanent Dagnew
Department of Fisheries and Aquatic Sciences, College of Agriculture and Environmental Sciences, Bahir Dar University, P. O. Box 79, Bahir Dar, Ethiopia.
Department of Biology, Faculty of Natural and Computational Sciences, Debre Tabor University, P. O. Box: 272, Debre Tabor, Ethiopia.
Heliyon. 2024 Dec 6;10(24):e40953. doi: 10.1016/j.heliyon.2024.e40953. eCollection 2024 Dec 30.
Nowadays, consumption of fish is becoming a public health concern due to quality and safety issues. This study was designed to assess the proximate composition, microbial quality, and heavy metal accumulation in the Nile tilapia fillet at three selected landing sites in Lake Tana. Fifteen samples were collected and analyzed. The mean moisture, ash, fat, protein, salt, and water activity were 81.76%, 0.98%, 1.88%, 14.04%, 0.14%, and 0.9869, respectively. The proximate contents varied slightly among sites but were not significantly different (p > 0.05). The mean aerobic mesophilic bacteria, , total coliform, and fecal coliform counts were 6.30 log CFU/g, 2.91 log CFU/g, 1.51 log MPN/g, and 0.89 log MPN/g, respectively. Such high microbial loads and the high counts of fecal coliforms are indicative of poor handling practices and unsanitary processing that might lead to foodborne illnesses and economic losses. In addition, the mean concentration of heavy metals in the tissue samples decreased in the order of chromium (0.165 mg/kg) > arsenic (0.085 mg/kg) > lead (0.054 mg/kg) > cadmium (0.010 mg/kg). Except for chromium, the concentrations of the assessed metals were below the maximum permissible limits. Long-term chromium exposure, especially in its hexavalent form, can pose significant health risks like respiratory issues, gastrointestinal distress, and even cancer. Therefore, identifying contamination sources, employing proper waste management strategies, continuous monitoring of heavy metal levels, and proper fish handling practices are highly recommended to address the health implications of microbial contamination and elevated chromium concentrations.
如今，由于质量和安全问题，鱼类消费正成为一个公共卫生问题。本研究旨在评估塔纳湖三个选定上岸点尼罗罗非鱼鱼片的近似成分、微生物质量和重金属积累情况。采集并分析了15个样本。平均水分、灰分、脂肪、蛋白质、盐分和水分活度分别为81.76%、0.98%、1.88%、14.04%、0.14%和0.9869。近似成分在不同地点略有差异，但差异不显著（p>0.05）。需氧嗜温菌、总大肠菌群和粪大肠菌群的平均计数分别为6.30 log CFU/g、2.91 log CFU/g、1.51 log MPN/g和0.89 log MPN/g。如此高的微生物负荷和粪大肠菌群的高计数表明处理方法不当和加工不卫生，这可能导致食源性疾病和经济损失。此外，组织样本中重金属的平均浓度顺序为铬（0.165毫克/千克）>砷（0.085毫克/千克）>铅（0.054毫克/千克）>镉（0.010毫克/千克）。除铬外，所评估金属的浓度均低于最大允许限值。长期接触铬，尤其是六价铬，会带来重大健康风险，如呼吸系统问题、胃肠道不适，甚至癌症。因此，强烈建议识别污染源、采用适当的废物管理策略、持续监测重金属水平以及正确的鱼类处理方法，以应对微生物污染和铬浓度升高对健康的影响。
