Influence of smoking parameters on the concentration of polycyclic aromatic hydrocarbons (PAHs) in Danish smoked fish

A review of hazards in meat products: Multiple pathways, hazards and mitigation of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are stable carcinogens that are widely distributed in the environment and food, and humans are exposed to PAHs primarily through the respiratory tracts, dermal contact, and dietary intake. Meat products are an essential part of the human diet, and the formation of PAHs during meat processing is unavoidable. Therefore, a comprehensive understanding of PAHs in meat products can be a contribution to the minimization of human exposure dose. The aim of this review is to provide a comprehensive description of the toxicological analysis of PAHs intake and the various production pathways. The distribution of different PAHs in various meat products, including poultry and aquatic products, is analyzed. The discussion focuses on controlling PAHs through the use of endogenous marinades and antioxidants as well as reducing exogenous particulate matter-PAHs attachment. In addition, potential strategies for PAHs reduction and possible directions for future research are proposed.

A Risk-Benefit Analysis of First Nation's Traditional Smoked Fish Processing

First Nations (FN) communities have traditionally used smoke to preserve fish for food security purposes. In this study, an assessment of chemical and microbiological food safety, together with nutritional quality, was conducted on fish preserved using traditional smoke processing. High-molecular-weight polycyclic aromatic hydrocarbons (PAH) residues accounted for only 0.6% of the total PAH in traditionally fully smoked salmon, and Benzo(a)pyrene (B(a)P) was not detected in the FN smoked or commercial smoked fish, respectively. The antimicrobial activity of the solvent extracts derived from smoked fish towards Listeria innocua was very low but detectable. The practice of using full and half-smoked processing for fish reduced all of the fatty acid concentrations and also minimized the further loss of essential omega-3 fatty acids to a greater extent than non-smoked fish during storage (p < 0.05). This finding corresponded to lower (p < 0.05) lipid oxidation in smoked fish. We conclude that the benefits of reducing lipid oxidation and retaining essential fatty acids during storage, together with a potentially significant reduction in Listeria contamination, are notable benefits of traditional smoke processing. Although B(a)P was not detected in FN smoked fish, attention should be given to controlling the temperature and smoking period applied during this processing to minimize potential long-term risks associated with PAH exposure.

Pantanal yacare (Caiman yacare) tail fillets subjected to traditional hot smoking and liquid smoke

BACKGROUND

The present study aimed to evaluate the effects of hot smoking and liquid smoke on process yield, physicochemical properties, microbiological parameters, fatty acid profile, benzo(a)pyrene levels, and sensory profile of Pantanal yacare tail fillets. The fillets were subjected to two types of smoking processes: hot smoking and liquid smoke flavoring.

RESULTS

The process yield of liquid-smoked fillets was higher (69.8%) compared to hot-smoked fillets (58.0%). All fillets were with good microbiological quality and low benzo(a)pyrene levels and were well accepted by consumers. The hot-smoked fillets and the liquid-smoked fillets presented 456.2 and 589.7 g kg^-1 moisture, 262.3 and 263.7 g kg^-1 crude protein, 218 and 85 g kg^-1 total lipids, and 26.0 and 20.9 g kg^-1 ash, respectively. The major fatty acids identified in the smoked tail fillets were palmitic, stearic, oleic, and linoleic acids.

CONCLUSION

The liquid-smoked fillets had lower lipid content, and higher process yield because of lower losses; thus, they proved to be more advantageous and practical to obtain than the hot-smoked fillets. © 2022 Society of Chemical Industry.

Investigations of the Polycyclic Aromatic Hydrocarbon and Elemental Profile of Smoked Fish

Fish are vulnerable to environmental pollutants such as polycyclic aromatic hydrocarbon and heavy metals. As one of the most commonly applied processing methods, the smoking of different species has been applied globally. Hence, this study aims to investigate the smoking process on the polycyclic aromatic hydrocarbon and elemental accumulation of the five different species (rainbow trout, Atlantic bonito, horse mackerel, sea bass, and Atlantic bluefin tuna) which are commonly processed and traded in the smoked fish industry. The processing yield, water holding capacity, and pH were also investigated. The results revealed that the proximal differences among fish species influence the water holding capacity, processing yield, and pH which are very important for process sustainability and the quality of the end product. The main finding was the proximal composition impact on the accumulation of both PAHs and heavy metals at different levels. While all of the tested samples were below the maximum permissible limit, some of the heavy metals, especially toxic elements, were found above the acceptable limit. Horse mackerel is determined to be the species most vulnerable to PAHs and heavy metal accumulation.

Detection of Nitrated, Oxygenated and Hydrogenated Polycyclic Aromatic Compounds in Smoked Fish and Meat Products

Polycyclic aromatic hydrocarbons (PAHs) are present in smoked food products. More toxic nitrated (NPAH) and oxygenated (OPAH) PAHs derivatives are found concomitantly to PAHs and are therefore believed to be found in smoked food products. However, only a few PAH analyses on food include these derivatives. We adjusted and successfully validated a GC-QTOFMS method including 13 NPAHs and 2 OPAHs as well as the 4 regulated PAHs for analysis of 14 smoked (13 fish and one bacon) and one pan fried fish samples.OPAHs were detected in the highest concentrations in 13 of 15 samples. Non-target screening revealed the presence of an additional four OPAHs and two methylated PAHs. Future food analysis should, based on these results, focus on PAH and oxygenated derivatives.

Analysis of four polycyclic aromatic hydrocarbons in plant-based food supplements-results of a collaborative study

The determination of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in food supplements is challenging, especially due to the presence of other e.g. heterogeneous PAH-like compounds in the matrix. A collaborative study with 12 participants was conducted in order to assess performance characteristics of a fast method intended to analyse the four regulated PAHs (PAH 4) benzo[b]fluoranthene [BbF], benz[a]anthracene [BaA], chrysene [CHR] and benzo[a]pyrene [BaP] in five different plant-based food supplements in the form of capsules, powder, and tablets. The principle of the method includes the extraction of PAHs with ethyl acetate: cyclohexane followed by a two-step SPE cleanup and final analysis by GC-MS or LC-FLD. The regulated maximum level for BaP is 10 µg/kg and, for the PAH 4, 50 µg/kg. Accordingly, the method was validated for the regulated PAH 4 analytically challenging concentration range from 2.5 µg/kg to 6.9 µg/kg. The performance criteria for the method set in European Regulation No 333/2007 for the overall repeatability, reproducibility (HorRat values below 2), and recovery (range 50-120%) were fulfilled. Based on the statistical evaluation of the results, it was concluded that the method is a suitable alternative to existing methods and should be studied for additional matrices.

Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Smoked Sardinella sp. in Ghana: Impact of an Improved Oven on Public Health Protection

An improved fish smoking oven called FAO-Thiaroye Technique (FTT) has been introduced in Ghana and other countries in the Global South as a technical intervention for the high levels of polycyclic aromatic hydrocarbons (PAHs) in traditionally smoked fish produced in those regions. This study evaluated the extent to which the intervention reduces consumer exposure to PAHs (considering benzo(a)pyrene [BaP] as a marker) in smoked fish, using Ghana as a case. Smoked Sardinella sp. were sampled from two traditional ovens (Chorkor smoker and metal drum oven) and the FTT and their PAH levels were determined by gas chromatography-mass spectrometry. Samples of the product were also purchased from informal markets in three selected regions of Ghana and analyzed for their PAH levels. Cross-sectional consumer surveys were conducted in the selected regions to determine intakes of the commodity. A probabilistic risk assessment of PAH was then done by the margin of exposure (MoE) approach. BaP MoE as low as 1,060 and 752 were obtained for products from the traditional ovens and the informal markets, respectively, whereas the lowest value for FTT products was approximately 161,000. MoE values less than 10,000 were considered to denote a serious public health concern requiring risk management action. Therefore, the findings suggest that there is a potential health concern of high consumer exposure to PAHs in traditionally smoked fish in Ghana, and that the FTT is a technically viable intervention for the problem.

Formation and mitigation of PAHs in barbecued meat - a review

Polycyclic Aromatic Hydrocarbons (PAHs) are chemicals, which can occur in barbecued or grilled foods, and particularly in meats. They originate from incomplete combustion of the heat source, pyrolysis of organic compounds, or fat-induced flame formation. This review therefore summarizes relevant parameters for mitigation of especially carcinogenic PAHs in barbecued meat. Consumption of PAHs increases the risk of cancer, and thus the relevance for the mitigation of PAHs formation is very high for barbecued meat products. Parameters such as heat source, barbecue geometry, and meat type as well as marinating, adding spices, and other antioxidants reduce the final benzo[a]pyrene and PAHs concentrations and minimize the exposure. Overall, mitigation of carcinogenic PAHs from barbecuing includes removal of visual charring, reducing fat pyrolysis by minimizing dripping from the meat onto the heat source, the use of acidic marinades or choosing leaner cuts of meat. Estimation of human exposure to barbecued meat, includes several challenges such as substantial differences in barbecuing frequencies and practices, heat sources and meat types used for grilling.

Effects of Smoking Temperature, Smoking Time, and Type of Wood Sawdust on Polycyclic Aromatic Hydrocarbon Accumulation Levels in Directly Smoked Pork Sausages

Smoking is an excellent food preservation method but also a source of contamination of foodstuffs with carcinogenic polycyclic aromatic hydrocarbons (PAHs). Herein we investigated the influence of smoking temperature, smoking time, and type of wood sawdust used as smoke source on PAH levels attained through controlled smoking of pork sausages. Four PAHs (benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[a]pyrene) were monitored, as required by European Commission Regulation 835/2011. PAH concentrations increased continuously both with higher temperatures (55-95 °C) and with longer smoking periods (2-9 h), although the level of benzo[a]pyrene exhibited a tendency to plateau after 6 h. Among seven types of hardwoods tested, plum, alder, and birch yielded PAH concentrations considerably higher than that of commonly used beech, and oak showed similar levels to beech while apple and, to a lesser extent, walnut caused lower levels of sausage contamination. These findings could guide the establishment of good practices in the smoked meat industry.

Review of polycyclic aromatic hydrocarbons (PAHs) in fish and fisheries products; a Sri Lankan perspective

Polycyclic aromatic hydrocarbons (PAHs) are emerging as important contaminants in smoked and smoke-dried fish and fish products. The smoking techniques and different parameters contribute to the PAH load in smoked fish. This review paper provides insight into the PAHs and their sources and pathways to fish, effects on human health, smoking parameters and PAHs, regulations, available information, gaps in present knowledge, and future prospects in smoked fish from Sri Lanka. Based on the very few available research reports on PAH levels in smoked fish from Sri Lanka, it is concluded that the smoked fish are not safe for human consumption according to the regulation limits published by the European Union (EU). It is therefore important to implement proper guidelines and produce a safe product to ensure that hazards are managed as appropriate Hazard Analysis and Critical Control Points (HACCP). Graphical abstract.

Dietary exposure to selected chemical contaminants in fish for the Danish population

The exposure to selected chemical contaminants from fish has been calculated for the Danish population, both for adults (15-75 years of age) and children (4-14 years of age). The Danish mean consumption of fish is 21 g person^-1 day^-1 for adults and 12 g person^-1 day^-1 for children. Fish consumption is the main food group contributor for exposure to mercury and dioxins and dioxin-like polychlorinated biphenyls (PCDD/F and DL-PCB) for the Danish population. Comparison of the mean exposure with the TDI or TWI values shows for these substances as well as for perfluorooctane sulphuric acid (PFOS) that the exposure is below the TDI/TWI values. However, even without taking other food groups into account, PCDD/Fs and DL-PCB exposure is close to the actual TWI-value. Calculation of the Margin of Exposure (MOE) for the sum of hexabromocyclododecanes (HBCDD) and polycyclic aromatic hydrocarbons (PAHs) revealed fish consumption to be of low concern for the consumer health regarding these contaminants.

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.

Critical Effects of Smoking Parameters on the Levels of Polycyclic Aromatic Hydrocarbons in Traditionally Smoked Fish and Meat Products in Finland

Eighty fish products and 62 meat products were sampled and analysed in Finland, in the year of 2012 for four marker polycyclic aromatic hydrocarbons (PAH4) with an accredited gas chromatography-tandem mass spectrometry method. In general, the determined PAH4 levels were relatively low and below the maximum levels. The mean concentrations of smoked fish samples were 0.7 μg·kg−1 for benzo[a]pyrene and 3.9 μg·kg−1 for the PAH4 sum, whereas in smoked meat samples, mean benzo[a]pyrene and PAH4 sum levels were 2.2 μg·kg−1 and 11 μg·kg−1, respectively. However, PAH4 sum concentrations ranged from not detected to 200 µg·kg−1 particularly among meat products, underlining the importance of controlling the smoking process. In this study, the effect of selected smoking parameters, i.e., smoking technique (direct/indirect), smoking time (less than five hours/more than five hours), smoke generation temperature (optimised/nonoptimised), and the distance (less than five metres/more than five metres) between the food and the smoke source, confirmed the linkage between the smoking factors and the PAH4 levels formed in fish and meat products. As guidance for a safe smoking process, it was demonstrated that an indirect smoking technique, a shorter smoking time, an optimised smoke generation temperature, and a longer distance from the smoke source generated lower PAH concentrations in food products. However, while a shorter smoking time generated lower PAH levels in meat products, the levels in fish products were unexpectedly higher than in those smoked for a longer time. Other factors, such as the smoking type (cold smoking/warm or hot smoking) and the fish size, may have affected this result.

Prediction of benzo[a]pyrene content of smoked sausage using back-propagation artificial neural network

BACKGROUND

Benzo[a]pyrene (BaP), a potent mutagen and carcinogen, is reported to be present in processed meat products and, in particular, in smoked meat. However, few methods exist for predictive determination of the BaP content of smoked meats such as sausage. In this study, an artificial neural network (ANN) model based on the back-propagation (BP) algorithm was used to predict the BaP content of smoked sausage.

RESULTS

The results showed that the BP network based on the Levenberg-Marquardt algorithm was the best suited for creating a nonlinear map between the input and output parameters. The optimal network structure was 3-7-1 and the learning rate was 0.6. This BP-ANN model allowed for accurate predictions, with the correlation coefficients (R) for the experimentally determined training, validation, test and global data sets being 0.94, 0.96, 0.95 and 0.95 respectively. The validation performance was 0.013, suggesting that the proposed BP-ANN may be used to predictively detect the BaP content of smoked meat products.

CONCLUSION

An effective predictive model was constructed for estimation of the BaP content of smoked sausage using ANN modeling techniques, which shows potential to predict the BaP content in smoked sausage. © 2017 Society of Chemical Industry.

Development of a Zeolite Filter for Removing Polycyclic Aromatic Hydrocarbons (PAHs) from Smoke and Smoked Ingredients while Retaining the Smoky Flavor

The popularity of smoked foodstuffs such as sauces, marinades, and rubs is on the rise. However, during the traditional smoking process, in addition to the desirable smoky aroma compounds, harmful polycyclic aromatic hydrocarbons (PAHs) are also generated. In this work, a selective filter was developed that reduces PAH concentrations in a smoke by up to 90% while maintaining a desirable smoky flavor. Preliminary studies using a cocktail of 12 PAHs stirred with a zeolite showed the potential for this zeolite to selectively remove PAHs from a simple solution. However, pretreatment of the smoke prior to application removed the PAHs more efficiently and is more widely applicable to a range of food ingredients. Although volatile analysis showed that there was a concomitant reduction in the concentration of the smoky compounds such as 2-methoxyphenol (guaiacol), 2-methylphenol ( o-cresol), and the isoeugenols, sensory profiling showed that the difference in perception of flavor was minimal.

A Critical Review about the Health Risk Assessment of PAHs and Their Metabolites in Foods

Polycyclic aromatic hydrocarbons (PAHs) are a family of toxicants that are ubiquitous in the environment. These contaminants generate considerable interest, because some of them are highly carcinogenic in laboratory animals and have been implicated in breast, lung, and colon cancers in humans. Dietary intake of PAHs constitutes a major source of exposure in humans. Factors affecting the accumulation of PAHs in the diet, their absorption following ingestion, and strategies to assess risk from exposure to these hydrocarbons following ingestion have received very little attention. This review, therefore, focuses on concentrations of PAHs in widely consumed dietary ingredients along with gastrointestinal absorption rates in humans. Metabolism and bioavailability of PAHs in animal models and the processes, which influence the disposition of these chemicals, are discussed. Finally, based on intake, disposition, and tumorigenesis data, the exposure risk to PAHs from diet is presented. This information is expected to provide a framework for refinements in risk assessment of PAHs.

Metabolism and excretion rates of parent and hydroxy-PAHs in urine collected after consumption of traditionally smoked salmon for Native American volunteers

Few studies have been published on the excretion rates of parent polycyclic aromatic hydrocarbons (PAHs) and hydroxy-polycyclic aromatic hydrocarbons (OH-PAHs) following oral exposure. This study investigated the metabolism and excretion rates of 4 parent PAHs and 10 OH-PAHs after the consumption of smoked salmon. Nine members of the Confederated Tribes of the Umatilla Indian Reservation consumed 50 g of traditionally smoked salmon with breakfast and five urine samples were collected during the following 24 h. The concentrations of OH-PAHs increased from 43.9 μg/g creatinine for 2-OH-Nap to 349 ng/g creatinine for 1-OH-Pyr, 3 to 6 h post-consumption. Despite volunteers following a restricted diet, there appeared to be a secondary source of naphthalene and fluorene, which led to excretion efficiencies greater than 100%. For the parent PAHs that were detected in urine, the excretion efficiencies ranged from 13% for phenanthrene (and its metabolite) to 240% for naphthalene (and its metabolites). The half-lives for PAHs ranged from 1.4 h for retene to 3.3h for pyrene. The half-lives for OH-PAHs were higher and ranged from 1.7 h for 9-OH-fluorene to 7.0 h for 3-OH-fluorene. The concentrations of most parent PAHs, and their metabolites, returned to the background levels 24 h post-consumption.

Meat subtypes and their association with colorectal cancer: Systematic review and meta-analysis

Associations between specific red meat subtypes and risk of colorectal cancer (CRC) have been investigated in a number of epidemiological studies. However, no publication to date has summarised the overall epidemiological evidence. We conducted a systematic review and meta-analysis of prospective studies (cohort, nested case-control or case-cohort studies), which reported relative risk (RR) estimates and 95% confidence intervals (CI) for the association between intake of meat subtypes with colorectal, colon or rectal cancer or colorectal adenoma risk. PubMed and ISI Web of Science were searched up until August 1, 2014. Nineteen studies examined meat subtypes (5 beef, 5 pork, 2 lamb, 1 veal and 19 poultry) and associations with colorectal, colon or rectal cancer risk and 4 studies examined associations with adenoma risk (1 beef and 4 poultry). Comparing highest versus lowest intake, beef consumption was associated with an increased risk of CRC (RR = 1.11, 95% CI = 1.01 to 1.22) and colon cancer (RR = 1.24, 95% CI = 1.07 to 1.44), but no association was found with rectal cancer (RR = 0.95, 95% CI = 0.78 to 1.16). Higher consumption of lamb was also associated with increased risk of CRC (RR = 1.24, 95% CI = 1.08 to 1.44). No association was observed for pork (RR = 1.07, 95% CI = 0.90 to 1.27), but some between study heterogeneity was observed. No association was observed for poultry consumption and risk of colorectal adenomas or cancer. This meta-analysis suggests that red meat subtypes differ in their association with CRC and its sub sites. Further analysis of data from prospective cohort studies is warranted, especially regarding the role of pork.

Health risk assessment of dietary exposure to polycyclic aromatic hydrocarbons in Taiyuan, China

Sixteen polycyclic aromatic hydrocarbons (PAHs) were determined in 24 duplicate-diet samples from people in Taiyuan during summer and winter in 2009. Dietary intake of PAHs for 2862 participants was subsequently estimated by a survey in Taiyuan. Results from these 24 samples were compared with a raw food study in Taiyuan in 2008. Three main sources of dietary PAHs are vegetables, wheat flour and fruits, the sum of which contributes 75.95% of PAHs in dietary food. Compared to the estimated value in raw food, much more B[a]P(eq) (benzo[a]pyrene equivalents) were detected in food samples collected in the duplicate-diet study in Taiyuan (60.75 ng/day). The cooking process may introduce more B[a]P(eq) into food, and the relative contribution of 16 PAHs in the diet would be changed during the cooking procedure.

Determination of polycyclic aromatic hydrocarbons in smoked fish samples by a new microextraction technique and method optimisation using response surface methodology

Microwave-assisted extraction coupled with dispersive liquid-liquid microextraction as a recently introduced method was applied to determine polycyclic aromatic hydrocarbons in Iranian smoked fish. The results showed that the interaction of hydrolysing solution volume with ethanol ratio, volumes of extracting and disperser solvent is significant in the obtained model. Optimized conditions were: a hydrolysing solution volume 10 ml with 50% ethanol, a pH of 5, and extracting and disperser solvent volumes of 150 and 500 μl respectively. The level of 16 polycyclic aromatic hydrocarbons (PAHs) was determined in 80 smoked fish consisting of four species. The contamination of benzo[a]pyrene in all samples except three was below the European Commission's maximum level of 2 μg kg(-1) for smoked fish, while the ∑4 PAHs (benzo[a]pyrene, chrysene, benzo[a]anthracene and benzo[b]fluoranthene) were between 3 and 12 μg kg(-1) wet weight in all samples. Of the species examined, Hypophthalmichthys molitrix had the highest PAHs (∑16).

Effect of smoke generation sources and smoke curing duration on the levels of polycyclic aromatic hydrocarbon (PAH) in different suites of fish

The research studied the impact of smoke generation sources on PAH contamination in four different smoke-cured fish (mackerel, sardine, tuna and Cigar minnows). The smoke sources used included acacia, sugarcane bagasse and mangrove. PAHs in the smoke-cured fish were analysed using Varian GC/MS (3800-GC) system. The mean total PAH concentrations in the smoked fish (n=108) ranged from 250.59-1376.09 μg/kg in tuna, cigar minnows, sardine and mackerel smoke-cured with sugarcane bagasse, mangrove and acacia for between 2 and 8h. The mean BaP levels for most fish cured with smoke from acacia and mangrove for between 2 and 8h were all above the European Commission set limit of 5.0 μg/kg. Positive correlations (at P=0.01, 2-tailed) were observed between PAH levels in smoked fish and lignin contents of wood type used for the smoke generation, the fat content and the smoke-curing duration. Risk assessment conducted using benzo[a]pyrene carcinogenic and mutagenic toxicity equivalency factors (TEF and MEF respectively) showed high risk associated with consuming fish smoke-cured with hard woods (acacia and mangroves). Sugarcane bagasse was found to be relatively the best and safest smoke-generating source for smoke-curing of fish among the three wood types when using the traditional kiln.

Headspace solid-phase microextraction with gas chromatography-mass spectrometry determination of naphthalene in the composite food samples from the 2011 Canadian total diet study in Ottawa

A method based on isotope dilution headspace solid-phase microextraction, followed by gas chromatography and mass spectrometry, was developed for the determination of naphthalene in foods. Optimum method sensitivity was achieved by the addition of NaCl in water at saturation and with the sample solution incubated at 30°C for 15 min. The method had good repeatability, with relative standard deviations of 3.5 and 1.5% at 5 and 30 ng/ml, respectively. This method was used to determine naphthalene in 159 food composite samples collected from the 2011 Canadian Total Diet Study. Naphthalene was detected in 93 (58.9%) food composite samples, mostly in products of meat and cereal, fast food, and miscellaneous foods. Among the 93 samples, only 51 (54.8%) samples were found to contain naphthalene at levels above 1 ng/g, with a maximum of 35 ng/g found in the herbs and spices composite sample. Method detection limits, estimated for each one of the food composite samples by using the lower-abundance ionm/z 127, varied considerably because of the matrix effect, ranging from as low as 0.0022 ng/g for water to as high as 16 ng/g for fatty sample, with an average of 1.6 ng/g.

Overview on polycyclic aromatic hydrocarbons: occurrence, legislation and innovative determination in foods

Polycyclic aromatic hydrocarbons are ubiquitous compounds, well-known to be carcinogenic, which can reach the food in different ways. Thus the analysis of such compounds has always been of great importance. The aim of the present review, is not only to give an overview of the most recent sample preparation and analytical approaches (such as pressurized liquid extraction, solid-phase microextraction, supercritical fluid extraction, etc.), but also to introduce such a topic to researchers who want to approach it for the first time; therefore, the most significant references related to general aspects, such as formation, toxicity, risk assessment, occurrence in food, are reported and briefly discussed.

Antimicrobial activity of salmon extracts derived from traditional First Nations smoke processing

Freshly caught salmon were hot smoked with the traditional smoke processing methods of the Tl'azt'en and Lheidli T'enneh First Nations communities, producing both half-smoked and fully smoked food products. To ascertain the nature of antimicrobial effects related to the smoking process, the residue content of 16 polyaromatic hydrocarbons (PAH) and total PAHs of smoked products were determined and correlated with smoking process duration. When compared with fully smoked samples, partially smoked fish had significantly less total PAHs and were composed solely of low-molecular-weight components, with phenanthrene, acenaphthylene, and napthlalene, respectively, being the most abundant. In contrast, fully smoked products possessed significantly higher levels of low- and high-molecular-weight PAHs, including benzo[a]pyrene. Sequential extractions of water, ethyl acetate, and hexane were performed to identify antimicrobial activity imparted by the traditional smoking process. No activity was observed in water or ethyl acetate extractions, whereas hexane extracts were inhibitory to Staphylococcus aureus, with more inhibition observed in fully smoked samples when compared with partially smoked samples. This study provides evidence that traditional smoke processing methods used by First Nations communities can provide value toward producing food products that have extended shelf lives, and protect against a prevalent common pathogen easily transmitted by humans to processed food through direct contact.

Effect of Native American fish smoking methods on dietary exposure to polycyclic aromatic hydrocarbons and possible risks to human health

Although it is known that polycyclic aromatic hydrocarbons (PAHs) can be found in smoked meats, little is known about their prevalence in Native American smoked fish. In this work, the effect of traditional Native American fish smoking methods on dietary exposure to PAHs and possible risks to human health has been assessed. Smoking methods considered smoking structure (tipi or shed) and wood type (apple or alder). Neither smoking structure nor wood type accounted for differences in smoked salmon content of 33 PAHs. Carcinogenic and noncarcinogenic PAH loads in traditionally smoked salmon were 40-430 times higher than those measured in commercial products. Dietary exposure to PAHs could result in excess lifetime cancer risks between 1 × 10(-5) and 1 × 10(-4) at a daily consumption rate of 5 g d(-1) and could approach 1 × 10(-2) at 300 g d(-1). Hazard indexes approached 0.005 at 5 g d(-1), or approximately 0.3 at 300 g d(-1). Levels of PAHs present in smoked salmon prepared using traditional Native American methods may pose elevated cancer risks if consumed at high consumption rates over many years.

PAH contamination in shellfish: modelling to estimate exposure

Polycyclic aromatic hydrocarbons (PAH) are known carcinogens and are abundant in the environment and foodstuffs. Currently the majority of PAH research focuses on benzo[a]pyrene (BaP), although a much greater range of PAH are known to have detrimental effects to human health. Monitoring a large number of PAH is expensive, time consuming and analytically demanding, yet there is currently no clear basis for determining which PAH should be monitored to give an indication of overall exposure. A thorough statistical examination of the relationships between different PAH in different foodstuffs has not previously been carried out. Using a test dataset of homogenised edible flesh from shellfish samples as a case study a modelling process using principal components analysis regression is proposed to determine which PAH subset (from a total of 27 monitored PAH) should be assessed as indicators for general PAH exposure. Multivariate ordination and clustering show that PAH concentrations of compounds of similar chemical structure can be highly correlated in the samples, e.g. the five ringed isomers PAHs benzo[b]fluoranthene, benzo[j]fluoranthene and benzo[k]fluoranthene. The model selection process determined which subsets of PAH can be used to predict the presence and abundance of other PAHs in shellfish samples. Models were more accurate in predicating PAHs concentrations of PAH where concentrations were measured above the limit of detection (LoD). PAH with values below the LoD were harder to predict accurately. The current analysis highlights that laboratories should focus on the following PAHs BaP, benzo[a]anthracene, benzo[g,h,i]perylene, phenanthrene, benzo[g,h,i]fluoranthene, chrysene, benzo[k]fluoranthene, benzo[b]fluoranthene and fluoranthene when analysing shellfish samples. Focussing monitoring on this group of PAH may give a better indication of overall PAH content of samples that the summed PAH indicator methods currently adopted.

Red meat consumption and cancer: reasons to suspect involvement of bovine infectious factors in colorectal cancer

An increased risk for colorectal cancer has been consistently reported for long-time consumption of cooked and processed red meat. This has frequently been attributed to chemical carcinogens arising during the cooking process of meat. Long-time fish or poultry consumption apparently does not increase the risk, although similar or higher concentrations of chemical carcinogens were recorded in their preparation for consumption. The geographic epidemiology of colorectal cancer seems to correspond to regions with a high rate of beef consumption. Countries with a virtual absence of beef in the diet (India) or where preferably lamb or goat meat is consumed (several Arabic countries) reveal low rates of colorectal cancer. In China, pork consumption has a long tradition, with an intermediate colorectal cancer rate. In Japan and Korea, large scale beef and pork imports started after World War II or after the Korean War. A steep rise in colorectal cancer incidence was noted after 1970 in Japan and 1990 in Korea. The consumption of undercooked beef (e.g., shabu-shabu, Korean yukhoe and Japanese yukke) became very popular in both countries. The available data are compatible with the interpretation that a specific beef factor, suspected to be one or more thermoresistant potentially oncogenic bovine viruses (e.g., polyoma-, papilloma- or possibly single-stranded DNA viruses) may contaminate beef preparations and lead to latent infections in the colorectal tract. Preceding, concomitant or subsequent exposure to chemical carcinogens arising during cooking procedures should result in increased risk for colorectal cancer synergistic with these infections.

Polyaromatic hydrocarbons of smoked cured muscle foods prepared by Canadian Tl'azt'en and Llheidli T'enneh First Nation communities

Tl'azt'en and Lheidli T'enneh First Nation communities have traditionally used smoking, drying, and salting of fish and game as preservation methods to enhance food security. Our results showed that levels of 16 polycyclic aromatic hydrocarbons (PAH) were significantly higher in smoked salmon samples compared to moose meats, and further, that PAH contents were also dependent on the duration of smoke processing. Benzo[a]pyrene (BaP) was not detected in fresh or partially smoked foods, but was present in both fully smoked moose (1.4 μg/kg) and fully smoked salmon (3.6 μg/kg) meats, respectively. The total concentrations of PAH present in fully smoked meats using traditional smoke processing methods employed by Tl'azt'en and Lheidli T'enneh nations indicate that a risk assessment is required to determine the safety of these smoke-processed foods.