Performances of the barrel kiln used in cottage industry for fish processing and effects on physicochemical characteristics and safety of smoked fish products.

BACKGROUND: In the traditional food sector, the smoking process and smoking-drying process are widely used to increase the shelf-life of seafood products. The smoking process and smoking-drying process are mainly performed using barrel kiln and wood as fuel in many West African countries. The present study evaluated the performances of the barrel kiln and its effects on physicochemical characteristics and safety of smoked fish (SF) and smoked-dried fish (SDF). Twelve follow-ups were conducted with three experimental processors and 24 samples of fish collected at different steps of processing were analyzed in a laboratory using standard methods. RESULTS: The extreme values of combustion temperature recorded during the smoking process (456.4 °C) and smoking-drying process (482.8 °C) were higher than 450 °C, the temperature at which wood pyrolysis generates polycyclic aromatic hydrocarbons (PAHs). Smoked fish were highly contaminated with PAHs, and showed maximal levels of benzo[a]pyrene (52.7 µg kg-1 ) and PAH4 (i.e. sum of benzo[a]pyrene, chrysene, benzo[b]fluoranthene and benz[a]anthracene) (290.9 µg kg-1 ) exceeding the European Union limits by about 25-fold. After smoking of Scomber scombrus and smoking-drying of Cypselurus cyanopterus, no significant differences were recorded for lipid, protein and biogenic amine contents between fresh and processed fish, even if the histamine content of both fish exceeded the limit fixed by the European Union regulation. CONCLUSION: The results obtained in the present study showed that smoked fish and smoked-dried fish produced using barrel kiln and wood fuel are highly contaminated by PAHs. Therefore, there is a need to improve the preservation practices of raw fish and smoking conditions to limit the contamination of end-products by PAHs known to be carcinogenic components for humans and to ensure consumer safety. © 2021 Society of Chemical Industry.

Chemical hazards in smoked meat and fish.

This review aims to give an insight into the main hazards currently found in smoked meat and fish products. Literature research was carried out on international databases such as Access to Global Online Research in Agriculture (AGORA) database, Science direct, and Google scholar to collect and select 92 relevant publications included in this review. The smoking process was described and five hazards mostly found in smoked fish and meat were presented. The heat-induced compounds such as polycyclic aromatic hydrocarbons, heterocyclic amines, and nitrosamines were found in smoked fish and meat. Other hazards such as biogenic amines and heavy metals were also present in smoked fish and meat. The levels of these hazards reported from the literature exceeded the maximal limits of European Union. A brief description of risk assessment methodology applicable to such toxic compounds and risk assessment examples was also presented in this review. As most of the hazards reported in this review are toxic and even carcinogenic to humans, actions should be addressed to reduce their presence in food to protect consumer health and to prevent public health issue.

Steam precooking, an effective pretreatment to reduce contamination with polycyclic aromatic hydrocarbons in traditionally smoked shrimp.

ABSTRACT: Traditionally smoked shrimps are highly contaminated with carcinogenic polycyclic aromatic hydrocarbons (PAHs). The effect of precooking methods such as boiling (7 and 15 min) and steaming (15 and 20 min) on shrimp smoking effectiveness was investigated through smoking duration and the change of moisture, protein content, and PAHs contamination. The consumer's perception of derived shrimps was highlighted by acceptability and Just-About-Right test using 7-point hedonic and 3-point scale respectively. Both precooking methods didn't affect the shrimp protein content while steaming reduced significantly moisture content. All the precooking methods reduced significantly the smoking duration with the lowest values for steaming. Smoking with or free from precooking increased significantly PAHs content of shrimp. Although, the PAHs trends showed similar pattern for both precooking methods, steaming during 20 min before smoking enables to have the shrimp with Benzo[a]pyrene (BaP) and sum of benzo[b]fluoranthene, benzo[a]anthracene, chrysene and BAP (PAH4) contents lower to the safety limit recommended by the European regulation. Irrespective of consumption forms, main sensory attributes of smoked steamed shrimps were scored as Just-About-Right by most consumers (65 to 88%). Steam precooking (20 min) is the better way for upgrading the shrimp safety with expected liking of consumers.

Consumption and physico-chemical characteristics of smoked and smoked-dried fish commonly produced in South Benin and contribution to recommended nutrient intakes.

The work aims to assess the consumption and the physico-chemical characteristics of smoked fish and smoked-dried fish commonly produced and consumed in the South Benin. The consumption data were obtained from a survey involving 250 consumers, conducted in selected production localities of the Southern part of Benin, where 36 samples of smoked fish and smoked-dried fish were collected. The highest protein contents (dry matter) were recorded in Cypselurus cyanopterus (85.1 ± 2.3%) and Sphyraena barracuda (84.5 ± 4.2%), while the highest lipid contents were recorded in Scomber scombrus (39.0 ± 9.2%) and Ethmalosa fimbriata (22.1 ± 6.3%). Smoked and smoked-dried fish produced in South Benin contained 0.1%-12.5% (of total fatty acids) eicosapentaenoic acid and 0.1%-33.2% docosahexaenoic acid, which are the most abundant omega 3 polyunsaturated acids in these fish products. The median consumption of smoked fish (60.2 g/day) and smoked-dried fish (18.2 g/day) contributed for 112% (281.1 mg) and 72% (180.4 mg), respectively, to the adult daily recommended intake of sum of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (250 mg/day). The daily protein intake related to the consumption of smoked fish and smoked-dried fish corresponded to 36% and 24%, respectively, of the recommended intake suggested by European Food Safety Authority (0.8 g/kg.bw/day).

Insight about methods used for polycyclic aromatic hydrocarbons reduction in smoked or grilled fishery and meat products for future re-engineering: A systematic review.

This paper presents methods of reduction of polycyclic aromatic hydrocarbons (PAHs) in grilled or smoked meat and fishery products. Using keywords such as "smoking", "grilling", "processing", "roasting", "barbecue", "curing", "reduction", "decrease", "polycyclic aromatic hydrocarbon", "benzo(a)pyrene", "removal", 1191 references were collected from databases. After sorting, only 37 appeared to be relevant to the topic of the review. These 37 papers were coded with one or two keywords representing methods of PAHs reduction using R-based Qualitative Data Analysis library. The results showed that PAHs reduction strategies can be applied either before (or during) grilling or smoking (barrier methods) or after grilling or smoking (removal methods). Before grilling or smoking, use of marinade, preheating of products, appropriate fuel (poor in lignin), filter, collection system of juice and fat (to avoid them dripping into embers) are the main strategies which can be applied. After grilling or smoking, the methods consist of washing the surface of smoked or grilled products with hot water (60 °C) or storing smoked products packed into low density or high density polyethylene. A flowchart regrouping methods which can be used individually or in combination for PAHs reduction in smoked meat and fishery products is suggested.

Polycyclic aromatic hydrocarbons contamination of traditionally grilled pork marketed in South Benin and health risk assessment for the Beninese consumer.

Polycyclic aromatic hydrocarbons (PAHs) contamination was monitored in grilled pork sold in Beninese street restaurants, as well as in grilled pork from a well-controlled experiment replicating traditional grilling using Acacia auriculiformis wood as fuel. Fifteen PAHs were analysed using a high-performance liquid chromatography method coupled with fluorescence detection. To assess the risk for the consumer, the margins of exposure (MOEs) were calculated, as the ratio between benchmark PAHs levels and consumer intakes. A MOE below 10,000 indicates a concern for human health for carcinogenic compounds such as PAHs. Benzo(a)pyrene (BaP) levels up to 17.9 and 53.6 µg/kg were found in grilled pork sampled in restaurants and from the controlled experiment, respectively. When considering both median estimated daily intake and median PAHs contamination levels, MOEs calculated for Benzo(a)pyrene (BaP) alone, or for the sum of 2, 4 or 8 PAHs were above 10,000, meaning no risk in these cases. However, for the same PAHs contamination level, MOE for consumers having large amounts of grilled pork (97.5th percentile and maximum level of pork consumption) were well below 10,000. When considering the maximum level of PAHs contamination, MOEs ranged between 257 and 2,757 for the high and median levels of consumption, indicating a safety concern for these consumers. This study reveals that Beninese grilled pork consumers from South Benin can be exposed to high levels of PAHs, which might result in public health issues.

Assessment of the physicochemical characteristics, chemical and microbiological safety of two types of kilichi, a grilled meat produced in Niger.

Production of kilichi, a grilled meat of West Africa, is a common method of meat preservation in Niger. Thirty samples of condiments-coated kilichi and uncoated kilichi collected in Niger, were analyzed for microbiological contamination, as well as NaCl, protein and lipid contents, using standard methods. Contamination with Polycyclic Aromatic Hydrocarbons (PAHs) was also assessed using a HPLC-FLD technique. Highly significant differences (p < .001) were observed between coated kilichi and uncoated kilichi, for NaCl content (2.56% and 1.40%), for proteins (51% and 72%) and lipids (18% and 13%), respectively. Water activity was low in both kilichi, showing a potential microbial stability. Among the 15 European Union (EU) priority PAHs, 12 were detected in the samples. About 56.3% of coated kilichi samples exceeded the EU maximal limit for BaP, and 75% exceeded the EU maximal limit for the sum of 4 PAHs (PAH4). For uncoated kilichi, 28.6% of samples did not meet the standards for BaP and PAH4. About 6% of coated kilichi samples were not compliant with standards related to Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, and 31%, 50% for yeasts and fungi, respectively. Escherichia coli and Enterobacteria were below the detection limit in both kilichi, but Salmonella and Bacillus cereus were detected only in one coated kilichi. The noncompliant samples of uncoated kilichi were in the proportions varying between 7% -86% for S. aureus, C. perfringens, yeasts, and fungi. This study showed potential risks associated with the consumption of traditionally produced kilichi in Niger due to both PAHs and pathogen bacteria contamination.

Microbiological characteristics of smoked and smoked-dried fish processed in Benin.

This study aimed to assess the microbiological status of smoked fish (SF) and smoked-dried fish (SDF) processed in Benin, and to identify the contamination factors associated with these products. A total of 66 fish samples, including fresh fish and processed fish, were randomly collected from different processing sites and markets for microbial characterization using standard methods. The aerobic mesophilic bacteria (AMB) density varied from 2.9 to 9.5 Log10 CFU/g. Enterobacteriaceae, Escherichia coli, Bacillus cereus, Clostridium perfringens, yeasts, and molds were present in 63.9%, 27.8%, 55.6%, 58.3%, 61.1%, and 77.8% of samples, respectively, while no Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus were found. The majority (66.7%) of SF samples and 22.2% of SDF samples were not compliant with the acceptable limit of <7.0 Log10 CFU/g recommended by the Health Protection Agency for AMB, whereas the Enterobacteriaceae counts exceeded the recommended level of 4.0 Log10 CFU/g for 50% of SF and 5.6% of SDF samples. Likewise, 38.9% of SF samples were not compliant for E. coli. Microbiological hazard analysis of practices allowed to identify the sensitive steps where hygiene measures need to be emphasized for an improved quality control.