B-vitamins and heat processed fermented starchy and vegetable foods in sub-Saharan Africa: A review.

Micronutrient deficiency still occurs in sub-Saharan Africa (SSA) despite the availability of several food resources, particularly fermented foods and vegetables, with high nutritional potential. Fermentation enhances the quality of food in several aspects. Organoleptically, certain taste, aroma, and textures are developed. Health and safety are improved by inhibiting the growth of several foodborne pathogens and removing harmful toxic compounds. Furthermore, nutrition is enhanced by improving micronutrient contents and bioavailability from the food, especially vitamin B content. However, during processing and before final consumption, many fermented foods are heat treated (drying, pasteurization, cooking, etc.) to make the food digestible and safe for consumption. Heat treatment improves the bioavailability of B-vitamins in some foods. In other foods, heating decreases the nutritional value because some B-vitamins are degraded. In SSA, cooked starchy foods are often associated with vegetables in household meals. This paper reviews studies that have focused fermented starchy foods and vegetable foods in SSA with the potential to provide B-vitamins to consumers. The review also describes the process of the preparation of these foods for final consumption, and techniques that can prevent or lessen B-vitamin loss, or enrich B-vitamins prior to consumption.

Assessment of heterocyclic aromatic amines contents in flamed and braised chicken in Burkina Faso.

The nutritional status of meat is tarnished by its association with the induced cooking contaminants. The aim of this study was to assess the heterocyclic aromatic amines profile and contents in processed chicken in Burkina Faso. Eight polar and apolar heterocyclic aromatic amines (HAAs) including 2-mino-3-methylimidazo[4,5-f]quinolone (IQ), 3-amino-1,4-dimethyl-5H-pyrido[4, 3-b]indole (Trp-P1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P2), 2-mino-9H-pyrido-[2,3-b]indole (AαC), 2-amino-1-methyl-6-phenylimidazo[4, 5- ]pyridine (PhIP), 2-amino-3-methyl-9H-pyrido[2,3-b] indole (MeAαC), 2-amino-3,4,8-rimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-3,8-imethylimidazo[4,5-]quinoxaline (MeIQx) were screened by high performance liquid chromatography from 29 samples of flamed chicken and 66 samples of braised chicken collected in Ouagadougou city. Apolar HAAs and polar HAAs were respectively 12 and 3 times more abundant in flamed chickens (32.66±10 and 3.48±10.39 ng/g, respectively) than in braised chickens (2.70±9.67 and 0.92 ng/g, respectively). The maximum levels of AαC were in the same proportions in flamed (12.01 ng/g) and braised chickens (14.13 ng/g). Flamed chicken had the highest Trp-P1 content (530.31 ng/g). The 4,8-DiMeIQx was not detected in braised chicken. The AαCs were more abundant in flamed than in braised chicken. The profile and the contents of the HAAs in processed chicken are related to cooking methods. Because of the high variability observed on the obtained concentrations, investigations on the contents of precursors in raw chicken, the effect of marinating ingredients on the formation of HAAs are needed.

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.

Polycyclic Aromatic Hydrocarbons Contamination of Flamed and Braised Chickens and Health Risk Assessment in Burkina Faso.

Charcoal- or wood-cooked chicken is a street-vended food in Burkina Faso. In this study, 15 samples of flamed chicken and 13 samples of braised chicken were analyzed for 15 priority polycyclic aromatic hydrocarbons (PAHs) with a high-performance liquid chromatography-fluorescence detector. A face-to-face survey was conducted to assess the consumption profiles of 300 men and 300 women. The health risk was assessed based on the margin of exposure (MOE) principle. BaP (14.95-1.75 µg/kg) and 4PAHs (BaP + Chr + BaA + BbF) (78.46-15.14 µg/kg) were eight and five times more abundant at the median level in flamed chickens than in braised ones, respectively. The contents of BaP and 4PAHs in all flamed chicken samples were above the limits set by the European Commission against 23% for both in braised chickens. Women had the highest maximum daily consumption of both braised (39.65 g/day) and flamed chickens (105.06 g/day). At the estimated maximum level of consumption, women were respectively 3.64 (flamed chicken) and 1.62 (braised chicken) times more exposed to BaP and 4PAHs than men. MOE values ranged between 8140 and 9591 for men and between 2232 and 2629 for women at the maximum level of consumption of flamed chickens, indicating a slight potential carcinogenic risk.

Rheological and textural properties of lafun, a stiff dough, from improved cassava varieties.

We studied the textural and rheological (viscoelastic) properties of fresh lafun dough, a fermented cassava product, and their changes during storage at 45 °C for 5 and 24 h, in order to determine after-cooking storability. Lafun flours were produced from three types of cassava varieties: seven improved white-fleshed varieties, seven improved provitamin A carotenoids (pVAC) varieties and two local white-fleshed varieties; and processed into lafun doughs. Pasting properties of the flours were assessed. Flours from local varieties had pasting profiles with highest viscosities, while pVAC flours had the lowest. The three types of cassava varieties varied significantly in most of their pasting properties. Four promising improved varieties were identified, based on high peak viscosity (55.8-61.5 P) and stiffer texture than local varieties during storage. Undesirable varieties were also found, which softened during storage instead of hardening. Optimum texture of lafun dough was obtained after 5 h of storage.

Concentrations and Health Risk Assessment of Metallic Trace Elements in Ready-to-Eat Braised and Flamed Chickens in Burkina Faso.

Braised and flamed chickens known as "poulet bicyclette" are famous and popular street food in Burkina Faso. Although they are important sources of a wide range of essential trace elements for humans, they can also contain toxic metals. The aim of the study was to assess the concentrations and health risk of metallic trace elements (Ag, Cr, Cu, Mn, Fe, Co, Zn, Ni, Cd, Pb) in ready-to-eat braised and flamed chickens in Burkina Faso. The concentrations and health risk assessment were estimated by atomic absorption spectrometry and hazard quotient method, respectively. The concentrations of Cu (3.12 mg kg-1), Fe (20.17 mg kg-1), and Ni (0.22 mg kg-1) were about 2 times higher in flamed chickens than in braised ones. Cd (0.45 mg kg-1) and Cr (2.50 mg kg-1) were 2 to 5 times more concentrated in braised chickens than flamed chickens. Pb was found in 72.72% of braised chicken and 62.06% of flamed chicken samples, above the maximum limit set by the JECFA. The daily intakes of Cu, Mn, Fe, and Zn contributed for less than 2% to the recommended daily intakes set by the Institute of Medicine of USA for both males and females, whereas Cr contributed for more than 20% from braised chicken. The estimated monthly intakes of Cd represented about 1.92-4.06% of the provisional tolerable monthly intake of Cd set by FAO/WHO. A non-cancer risk estimated as hazard index has been recorded at the maximum level of consumption for female consumer group for flamed chicken (HI = 2.14). The estimated cancer index risk in this study is below the reference value (10-4) set by the United States Environmental Protection Agency (US EPA).

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.

Optimal fermentation parameters for processing high quality African locust bean condiments.

Fermented African locust bean (ALB) condiments are widely used to enhance the aroma and the taste of various dishes in West Africa. They are a good source of proteins. Sonru is one of the ALB condiments processed in Benin using a traditional starter called yanyanku. The variability in sonru processing unit operations (e.g. fermentation) presumably affects the quality (microbiological, biophysical and sensorial) of the final product. This study aimed at optimizing the fermentation step of sonru based on response surface methodology including three-factors [i.e. proportion of yanyanku, fermentation duration and thickness/depth of the layer of ALB (TALB)] and three-level factorial Box Behnken design with four central point replicates. The pH, softness of fermented cotyledons, Bacillus spp. and aerobic mesophilic bacteria count of sonru were evaluated. In addition, consumer acceptability was assessed by 7-hedonic box scale and Just About Right analysis. The pH had an upward trend with the increasing of all factors, and particularly Bacillus spp. count had similar trend with the fermentation duration and TALB whereas maximal penetration force (referred as the softness) had a downward trend with the fermentation duration. The optimal fermented ALB condiment resulted from processing conditions set at 1‰ of yanyanku, 24 h of fermentation and 8.5 cm for TALB. The optimized sonru appeared to be ideal in color, softness and taste. These findings can be used to improve fermented ALB condiments processing and better control the product quality in African countries. Further studies are needed to improve the odor of sonru.

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.

Optimization of the marinating conditions of cassava fish (Pseudotolithus sp.) fillet for Lanhouin production through application of Doehlert experimental design.

Lanhouin is a traditional fermented salted fish made from the spontaneous and uncontrolled fermentation of whole salted cassava fish (Pseudotolithus senegalensis) mainly produced in the coastal regions of West Africa. The combined effects of NaCl, citric acid concentration, and marination time on the physicochemical and microbiological characteristics of the fish fillet used for Lanhouin production were studied using a Doehlert experimental design with the objective of preserving its quality and safety. The marination time has significant effects on total viable and lactic acid bacteria counts, and NaCl content of the marinated fish fillet while the pH was significantly affected by citric acid concentration and marination duration with high regression coefficient R (2) of 0.83. The experiment showed that the best conditions for marination process of fish fillet were salt ratio 10 g/100 g, acid citric concentration 2.5 g/100 g, and marination time 6 h. These optimum marinating conditions obtained present the best quality of marinated flesh fish leading to the safety of the final fermented product. This pretreatment is necessary in Lanhouin production processes to ensure its safety quality.

Effect of fuel and kiln type on the polycyclic aromatic hydrocarbon (PAH) levels in smoked shrimp, a Beninese food condiment.

Smoked shrimp is a food condiment widely used in Beninese local cooking practices. A previous study revealed that this product is highly contaminated with polycyclic aromatic hydrocarbons (PAH). The present study explored possibilities to reduce PAH levels in shrimp smoked using cottage industry smoking techniques with barrel and chorkor kilns, by replacing wood by charcoal from Acacia auriculiformis and Mangifera indica, as fuels. Results showed that only shrimp smoked using acacia charcoal in a chorkor kiln had PAH levels (benzo[a]pyrene = 5 µg kg(-1) and sum of benzo[a]pyrene, chrysene, benzo[a]anthracene and benzo[b]fluoranthene = 28 µg kg(-1)) in accordance with a European standard of 5 and 30 µg kg(-1), respectively, and suitable physicochemical characteristics for good storage (moisture content = 11.9% ± 1.5%; water activity = 0.46 ± 0.03). However, further investigations still needs to be done to reduce the duration of product contact with combustion gasses in order to reduce the PAH content of smoked shrimp to safer levels, largely below standards.