Smoked fish is widely consumed in Nigeria and may serve as a route of exposure to microbial contamination and toxic metals. This study assessed microbial quality, spoilage indicators, proximate composition, and heavy metal content associated with smoked Clarias gariepinus obtained from two farms (A and B) and two markets (A and B) in Ibadan, Nigeria, with implications for public health. Spoilage indicators were higher in market-sourced samples, with peroxide values ranging from 0.93 ± 0.40 mEq/kg in Farm B to 3.37 ± 0.29 mEq/kg in Market B. Total volatile base nitrogen and thiobarbituric acid values were also elevated, indicating increased lipid oxidation and protein degradation. Total viable (3.68 ± 0.79) × 10⁴ and fungal counts (2.66 ± 0.54) × 10⁵ were higher in market samples, although coliforms were not detected. Microbial profiling revealed greater diversity in market fish, including Pseudomonas, Aspergillus, Saccharomyces, and Geotrichum. Proximate composition was comparable across sources, with low moisture content (4.70–6.70%) and water activity (0.850–0.910), reflecting effective drying. Heavy metal concentrations were generally low in farmed fish but higher in market samples, particularly Market B, following the order arsenic > chromium > lead > cadmium, while mercury was not detected. Estimated daily intake and target hazard quotient values were below established safety thresholds, indicating no health risk. However, elevated spoilage indices and metal levels in market fish highlight the need for routine monitoring to protect consumer health.
Keywords: Biochemical Spoilage; Fish; Markets; Microbial Quality
Dahi, or yogurt, is a popular fermented dairy food in Bangladesh. Its broad use emphasizes the significance of ensuring microbiological safety, especially as it is frequently marketed under various storage conditions. Consumers may be at risk if cleanliness and storage standards are lacking. The purpose of this study was to evaluate the microbiological purity and safety of yogurt samples, both refrigerated and non-refrigerated, gathered from 10 different locations in Dhaka's Savar neighborhood. A total of twenty yogurt samples were examined, consisting of ten samples at room temperature and ten samples refrigerated. Microbiological tests were performed in accordance with World Health Organization (WHO) guidelines, with an emphasis on total viable bacterial counts, coliforms, and fungal contamination (including yeast and mold). Total viable bacterial counts in refrigerated samples were between 2.02 × 10⁶ and 2.82 × 10⁶ CFU/ml. Non-refrigerated samples had significantly higher counts, ranging from 3.01 × 10⁶ to 3.87 × 10⁶ CFU/ml. Coliform contamination of up to 10 CFU/ml was found in non-refrigerated samples, which could pose health hazards. Furthermore, fungal contamination (yeast and mold) was substantially greater in non-refrigerated samples. Even in the lack of microbiological requirements established by the Bangladesh Standards and Testing Institution (BSTI), these findings highlight the importance of stricter handling, storage, and hygiene procedures. Adopting Good Manufacturing Practices (GMP) and Good Hygiene Practices (GHP) is necessary to assure the safety and quality of yogurt products in regional markets.
Bioresearch Commu. 12(2): 2193-2199, 2026 (January)
M. Haque, Sharmin Sultana Akhi, Suma Akter et al.· Bioresearch communications· 0 citations
Storage of processed fish can improve food and nutrition security. But little is known about the microbial status or occurrence of mycotoxins during long-time storage of traditionally processed small fish for domestic markets. Fish processors from three different regions in Ghana processed anchovies (Engraulis encrasicolus) using two different smoking techniques (Chorkor and Ahotor oven) and two different sun-drying techniques (on the floor and on elevated racks), respectively, followed by traditional storage in paper-lined baskets. Samples directly after processing and after three, six, and nine months of storage were analysed for several microbial parameters and content of mycotoxins. Both smoking techniques resulted in lower numbers of total colony counts, moulds, coliforms and Clostridium spp. compared to both sun-drying procedures. Bacteria counts in samples of processed and stored anchovies were below national regulatory thresholds and were evaluated suitable for consumption from a microbiological safety standpoint. Aflatoxin B1 was not detected in any sample. Ochratoxin A was found in anchovies dried on elevated racks with increasing levels during storage. In conclusion, all tested preservation methods and storage environments in this study were able to produce anchovies of marketable quality. The presence of mycotoxins calls for further investigation to determine the risk for humans. Smoking resulted in lower bacterial counts compared to sun-drying. Bacterial counts did not increase during storage, while mould counts did increase. No aflatoxins were detected but ochratoxin A increased during storage.
L. Wessels, T. Annan, A. Atter et al.· Food Safety and Risk· 0 citations
Poor quality drinking water pose a public health risk to consumers and contribute to waterborne disease burden especially in developing countries. This study assessed the quality of sachet and bottled water produced by a university coded Uni and three private business owners (Lom, Olv and Tai) in Benin City, Nigeria. Microbiological analysis involved the use of traditional methods, while physicochemical properties, essential and toxic metals content of the samples (n = 24) were determined using standard methods. Kirby-Bauer disc diffusion method was used to test antibiotic susceptibility of the bacterial isolates. The total heterotrophic bacterial count and total fungal counts of the Uni brand of drinking water ranged between 2.48 - 2.64 and 2.00 - 3.70 log10CFU/mL, while other brands was 2.78 - 7.36 and 1.00 - 3.60 log10CFU/mL, respectively. No coliforms were detected in the Olv and Uni brands of drinking water. The physicochemical properties, essential and toxic metals content of the samples were below permissible limits stipulated by the World Health Organization (WHO) for drinking water, with some exceptions. Among the isolates, Staphylococcus aureus had the least multiple antibiotic resistant index of 0.0, whereas the highest involved Proteus mirabilis and Escherichia coli reported as 0.4 each. Although, the overall results indicate that the Uni branded product was relatively better than others, regulatory bodies such as National Agency for Food and Drug Administration and Control (NAFDAC) should intensify its efforts in monitoring the production, storage, and distribution of sachet and bottled water to ensure strict compliance with international standards.
N. Maduka, H. Obueh· Journal of Science Research...· 0 citations
Fish smoking remains a widely practiced preservation method in Nigeria, playing a critical role in extending shelf life, enhancing sensory quality, and facilitating distribution in the absence of reliable cold-chain systems. This study assessed the availability, marketability, and consumer acceptance of smoked Clarias gariepinus (African catfish) and Oreochromis niloticus (Nile tilapia) in Ugbolu and Ogbeogonogo markets, Asaba, Delta State, Nigeria. A cross-sectional survey design integrating quantitative and qualitative approaches was employed. Data were collected from 120 respondents comprising fish sellers and consumers using structured questionnaires, interviews, and direct market observations. Descriptive statistics and inferential analyses, including analysis of variance, were used to evaluate differences in consumer acceptance and market performance. Results indicated that smoked Clarias gariepinus was more consistently available and exhibited higher marketability compared to Oreochromis niloticus, with greater sales rate, demand, and profitability. Consumer acceptance differed significantly between the two species (p < 0.05), with catfish recording higher scores across taste, aroma, texture, and overall acceptability. Preference patterns were strongly influenced by sensory attributes, price, and product availability. The dominance of catfish was attributed to its favourable processing characteristics, extended shelf stability, and strong consumer appeal, whereas tilapia served as a more affordable alternative with moderate acceptance. Despite the strong demand for smoked fish, constraints such as supply fluctuations, inadequate storage infrastructure, and competition from imported fish products were identified. The study highlights the need for improved processing technologies and efficient value chain management to enhance product quality, market performance, and sustainability of the smoked fish sector.
J. Akpotu· Lafia Journal of Scientific...· 0 citations
Dried fruits and nuts are widely consumed for their desirable sensory qualities and high nutritional value, providing essential nutrients such as proteins, healthy fatty acids, potassium, dietary fiber, and bioactive compounds. However, they are highly susceptible to aflatoxin contamination, particularly in humid tropical regions like Bangladesh. This study investigated toxigenic fungal contamination and quantified aflatoxin (B
1
, B
2
, G
1
, and G
2
) levels in dried fruits and nuts collected from markets in Dhaka city, Bangladesh.
Mean fungal counts were 84.5 ± 3.20 CFU/g, 72.8 ± 3.81 CFU/g, and 58.0 ± 4.24 CFU/g in nuts, raisins, and dates, respectively. The identified genera included
Aspergillus
,
Penicillium
,
Rhizopus
, and
Fusarium
, with
Aspergillus
being predominant (95.23%). Aflatoxins were present in 57.14% of samples, with concentrations ranging from 1.22 to 81.97 μg/kg. Mean aflatoxin levels were 4.15 ± 0.32 μg/kg in dates, 44.38 ± 34.19 μg/kg in raisins, and 3.27 ± 1.79 μg/kg in nuts, with aflatoxin B
1
being dominant. Over one‐third of samples exceeded the European Commission's threshold of 4 μg/kg. Dietary exposure ranged from 1.50 to 27.31 ng/kg‐bw/day, with liver cancer risk greatest among Hepatitis B surface antigen (HBsAg)‐positive individuals.
The high occurrence of carcinogenic aflatoxins in dried fruits and nuts poses a significant public health concern, underscoring the urgent need for improved pre‐ and post‐harvest practices, regular surveillance, and stricter regulatory measures to ensure food safety and protect consumers.
Tasniya Akter, Mohammad Tariqul Hassan, A. Nowar et al.· JSFA Reports· 0 citations
This study evaluated the effects of warm water containing wood ash on the microbial aflatoxin B1, and nutritional contents of smoked dried croaker (Micropogonius undukiuts), catfish (Siluriformes sp.), and tilapia (Oreochromis niloticus) sold in Akure, Nigeria. Raw and treated samples (cold water, warm water, and warm water with wood ash) were analyzed for microbial load using standard cultural methods, aflatoxin B1 by spectrophotometry, and nutritional composition by chemical methods. Bacterial counts ranged from 20.0 × 10³ to 29.0 × 10³ CFU/g, and mold counts ranged from 2.0 × 10³ to 12.0 × 10³ SFU/g across different markets. Pre-treatment with the sterilizing solutions, particularly warm water containing wood ash, significantly reduced microbial and aflatoxin B1 levels while preserving nutritional quality. Identified microorganisms included pathogenic and spoilage species such as Escherichia coli, Staphylococcus aureus, Klebsiella sp., Bacillus subtilis, Pseudomonas aeruginosa, Aspergillus flavus, A. niger, and Rhizopus stolonifer. The results demonstrate that warm water containing wood ash effectively reduces microbial and aflatoxin contamination in smoked fish without compromising nutritional value, suggesting it as a practical, low-cost decontamination method for improving fish safety and quality in local markets.
O. Olaniyi, Folakemi Akoyiola Blessing· Journal of food safety and h...· 0 citations