Effects of grilling procedures on levels of polycyclic aromatic hydrocarbons in grilled meats

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.

Barbecued desi chicken: an investigation on the impact of polluted milieu upon formation and ingestion of polycyclic aromatic hydrocarbons (PAHs) in commercial versus laboratory barbecued organs along with stochastic cancer risk assessments in people from an industrial district of Punjab, Pakistan

8∑PAHs in 2- and 4-month-old desi chicken organs collected from Faisalabad district, Punjab, Pakistan, were examined via high-performance liquid chromatography (HPLC). Exposure doses (A_VDD) of PAHs with consequential lifetime excess cancer risks (L_tECR) were also estimated in people ingesting laboratory barbecued (L_b) and commercially barbecued (C_b) desi meat organs. The results exposed the presence of 8ΣPAH in 2- and 4-month-old L_b and C_b chicken organs: drumsticks (D_s), breast (B_S), and wings (W_s) (0.45, 3.10, 0.97 ng g^-1; 2.52, 4.31, 1.22 ng g^-1; and 10.09, 15.04, and 9.06 ng g^-1 respectively). BαP was found only in C_b organs with the highest concentrations (5.08 ng g^-1) in B_s. It was above the EU's tolerable limit, while it was not detected in all L_b organs. The lowest level of 8ΣPAH was found in 2-month-old desi W_s. A comparative percentage increase in 8ΣPAH levels between all L_b and C_b organs was found in the range of 1500-2416.67%. L_tECR for males and adults were ranging from 1.35 × E^-13 to 4.49 × E^-5 at different consumption rates with A_VDD ranging from 1.08 E^-6 to 6.01 E^-5. In contrast to 2- and 4- month-old chicken meat, 2-month-old desi meat is better having less PAH load. Comparing different organs, W_s of former one displayed abridged PAH levels. In conclusion, L_b desi meat is less carcinogenic relative to C_b. More PAH levels are due to secondary smoke in C_b samples collected from the metropolitan. Ingestion of L_b 2-month-old desi chicken organs could be safe to dine as compared with 4-month-old desi and C_b organs. Graphical abstract.

Detecting cooking state of grilled chicken by electronic nose and computer vision techniques

Determination of food doneness remains a challenge for automation in the cooking industry. The complex physicochemical processes that occur during cooking require a combination of several methods for their control. Herein, we utilized an electronic nose and computer vision to check the cooking state of grilled chicken. Thermogravimetry, differential mobility analysis, and mass spectrometry were employed to deepen the fundamental insights towards the grilling process. The results indicated that an electronic nose could distinguish the odor profile of the grilled chicken, whereas computer vision could identify discoloration of the chicken. The integration of these two methods yields greater selectivity towards the qualitative determination of chicken doneness. The odor profile is matched with detected water loss, and the release of aromatic and sulfur-containing compounds during cooking. This work demonstrates the practicability of the developed technique, which we compared with a sensory evaluation, for better deconvolution of food state during cooking.

Effect of charcoal type on the formation of polycyclic aromatic hydrocarbons in grilled meats

The effect of grilling using three charcoal types (white, black, and extruded charcoal) on the formation of 16 polycyclic aromatic hydrocarbons (PAHs) in three types of meat (beef loin, pork belly, and chicken thigh) was evaluated. Meats were grilled using a standardized technique until an internal temperature of 71-75 °C was reached. The limits of quantitation, relative recoveries, and precisions of the PAH analyses using GC/MS were 0.03-0.31 μg/kg, 73.5-120.5%, and 0.54-5.02%, respectively. Meats grilled using extruded charcoal showed the highest levels of PAHs (p < 0.0001) among the different charcoals. Additionally, higher levels of 4 PAHs were found in pork belly than beef loin and chicken thigh meat, due to its high fat content (p < 0.0001). The effects of charcoal and meat types showed a high coefficiency (p < 0.0001). These results indicated that the combination of white charcoal and low-fat meat could reduce PAHs formation in charcoal-grilled meat.

The Presence of Polycyclic Aromatic Hydrocarbons (PAHs) in Grilled Beef, Chicken and Fish by Considering Dietary Exposure and Risk Assessment

Polycyclic aromatic hydrocarbons (PAHs) are dangerous chemical compounds that can be formed by cooking foods at high temperatures. The aim of this study is to determine the level of contamination of PAH compounds with high performance liquid chromatography (HPLC) on heat treated meat samples and the consumption of PAH compounds in meat samples, as well as the dietary exposure status and possible health risk estimation. In five different heat treated meat samples (meat doner, chicken doner, meatballs, grilled chicken, and fish), the total PAH (Σ16PAH) contamination level was 6.08, 4.42, 4.45, 4.91, and 7.26 μg/kg, respectively. Benzo[a]pyrene (BaP) in meatballs and grilled fish samples had a level 0.70 and 0.73 μg/kg. All of the samples analyzed were found to be below the EU permitted limit (5 μg/kg) in terms of BaP. Estimates of daily intake (EDI) for a total of 16PAH in heat treated meat doner, chicken doner, meatballs, grilled chicken and fish samples were 3.41, 3.71, 2.49, 4.12, and 1.77 ng/kg bw/day, respectively. In this study, the average margin of exposure (MOE) value calculated was found in the range of 179.487 and 425.000 for BaP and PAH4. This study is the first study to provide important information in terms of evaluating the possible health risk that PAH compounds can create in people's diets due to heat treatment of meat and meat products in Sivas, Turkey.

The effects of extracting procedures on occurrence of polycyclic aromatic hydrocarbons in edible oils

Polycyclic aromatic hydrocarbons (PAHs) are one of the most hazardous naturally occurring chemical contaminants of food. Edible oils are easily contaminated by PAHs generated during high-temperature processing steps such as oil extraction and refining. In this study, the effects of different extraction methods on the levels of PAHs in sesame oils and red pepper seed oils were assessed. GC-MS was used to determine the levels of PAHs in edible oils. Sesame oils extracted from seeds by plate-pressing extraction method had lower levels of PAHs than those extracted by screw-expeller extraction method from sesame flour. Furthermore, the levels of PAHs increased by 62.2% when the extraction time was longer. Notably, the PAHs already present in oils could be effectively reduced by refining procedures such as sinking, centrifugation, filtration, and neutralization with alkali.

Evaluation of optimal QuEChERS conditions of various food matrices for rapid determination of EU priority polycyclic aromatic hydrocarbons in various foods

Optimal QuEChERS (quick, easy, cheap, effective, rugged and safe) conditions with good accuracy, repeatability and precision were established to rapidly extract the European Union (EU) priority polycyclic aromatic hydrocarbons (PAHs) from various food matrices (Category: Poultry and Meat, Fish and seafood, Grains, Soy beans and products, Root vegetables and Coffee). The QuEChERS conditions combined with the established high performance liquid chromatography-fluorescence detection conditions were used to rapidly determine the PAHs in 19 popular cooked foods in Taiwan and their corresponding original materials. These conditions also meet the EU and Taiwan Food and Drug Administration specifications. Charcoal grilled, gas stove grilled and smoked foods had higher PAHs contents, while fried and electric oven-baked/baked foods had lower PAHs contents. In addition to the effects of cooking methods, the contamination of original materials by PAHs in the environment should also have an important impact on the contents of PAHs in these cooked foods.

The effect of gas versus charcoal open flames on the induction of polycyclic aromatic hydrocarbons in cooked meat: a systematic review and meta-analysis

PURPOSE

Open flames of gas and charcoal can induce polycyclic aromatic hydrocarbons (PAHs) in cooked meat. The current study aimed to compare the effect of gas and charcoal open flames on the induction of PAHs in cooked meat using a meta-analysis approach.

METHODS

A systematic review of the literature was conducted electronically based on the PRISMA guidelines. Experimental studies comparing the PAHs content of cooked meat over open flames of gas and charcoal were searched using the appropriate keywords until June 2018.

RESULTS

Of 1137 papers retrieved, 7 with a total sample size of 474 meat samples were used in the meta-analysis. The mean difference (MD) between the gas and charcoal cooking methods in the induction of each PAH was 2.053 μg/Kg. (95%CI: 1.022-3.085 μg/Kg; P < 0.001). The subgroup analysis of 17 trials indicated the difference between the two cooking methods increases when red meat rather than white meat is cooked (MD in red meat: 3.499 μg/Kg; 95%CI: 2.030-4.967; P < 0.0001 vs. MD in white meat: 3.319 μg/Kg; 95% CI: 1.689-4.950; P < 0.0001). Interestingly, studies that analyzed meat samples for fewer PAHs (cut-off ≤7) found a much wider difference between gas and charcoal-cooked meat (MD: 5.106 μg/Kg; (95% CI: 2.162-8.049; P < 0.001 in studies with ≤7 PAHs vs. MD: 1.447 μg/Kg; 95% CI: 0.628-2.266; P < 0.001 in studies with >7 PAHs).

CONCLUSIONS

It is necessary to avoid open flames of charcoal as the heat source or change the geometry of charcoal-fired cookstoves to prevent fat dripping on the fire and thus, excessive PAHs induction.

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.

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 in edible oils and fatty foods: Occurrence, formation, analysis, change and control

Numerous studies have demonstrated that dozens of polycyclic aromatic hydrocarbons (PAHs) are mutagenic, genotoxic and strongly carcinogenic. PAHs are found to be widely present in foods contaminated through multiple paths. Due to their lipophilic nature, these compounds easily accumulate in edible oils and fatty foods where they can range from no detection to over 2000μg/kg. Compared to precursor PAHs, researchers have seldom studied the presence of PAH derivatives, especially in food matrices. This chapter includes the physical and chemical characteristics of PAHs and their types, occurrence, sample pretreatment and instrumental determination methods, and their formation, change and control in edible oils and fatty foods. The occurrence and formation of PAH derivatives in foods are much less investigated compared to those of their precursor PAHs. Although the removal of matrix effects and accuracy remain difficult for current rapid determination methods, a prospective research direction of PAH analysis for large-scale screening is in demand. To date, physical absorption, chemical oxidation and biodegradation have been widely used in PAH removal techniques. Specific types of bacteria, fungi, and algae have also been used to degrade PAHs into harmless compounds. However, most of them can only degrade a range of LPAHs, such as naphthalene, anthracene and phenanthrene. Their ability to degrade HPAHs requires further study. Moreover, it is still a great challenge to maintain food nutrition and flavor during the PAH removal process using these methods.

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.

Cocoa beans of different origins and varieties and their derived products contamination with polycyclic aromatic hydrocarbons

Levels of polycyclic aromatic hydrocarbons (PAHs) in cocoa beans of several varieties originating from different countries and their derived products from one technological line were examined. PAHs analysis was performed using HPLC-FLD/DAD and confirmed by GC-MS. Significant differences in total 19 PAHs contents between raw cocoa beans of different varieties and origins were observed. The highest sums of 19 PAHs were determined in roasted cocoa beans, cocoa mass and cocoa butter (16.69-74.15 μg kg^-1 of fat). The roasting temperature of 160 °C led to PAHs formation, though not the heavy ones. Lowering temperature to 140 °C while extending the time minimized the total contamination but to a small extent. In all samples relatively low levels of total contamination were noted, with light PAHs being predominant and the sum of 4 heavy and marker PAHs much lower than the maximum legal limit. Therefore, analysed products, especially chocolate, do not threaten consumers' health.

THE EXPOSOME IN HUMAN EVOLUTION: FROM DUST TO DIESEL

Global exposures to air pollution and cigarette smoke are novel in human evolutionary history and are associated with about 16 million premature deaths per year. We investigate the history of the human exposome for relationships between novel environmental toxins and genetic changes during human evolution in six phases. Phase I: With increased walking on savannas, early human ancestors inhaled crustal dust, fecal aerosols, and spores; carrion scavenging introduced new infectious pathogens. Phase II: Domestic fire exposed early Homo to novel toxins from smoke and cooking. Phases III and IV: Neolithic to preindustrial Homo sapiens incurred infectious pathogens from domestic animals and dense communities with limited sanitation. Phase V: Industrialization introduced novel toxins from fossil fuels, industrial chemicals, and tobacco at the same time infectious pathogens were diminishing. Thereby, pathogen-driven causes of mortality were replaced by chronic diseases driven by sterile inflammogens, exogenous and endogenous. Phase VI: Considers future health during global warming with increased air pollution and infections. We hypothesize that adaptation to some ancient toxins persists in genetic variations associated with inflammation and longevity.

Concentrations and distributions of polycyclic aromatic hydrocarbon in vegetables and animal-based foods before and after grilling: Implication for human exposure

The effects of grilling on health risks posed by polycyclic aromatic hydrocarbons (PAHs) in food remain poorly understood. The changes of concentrations, distributions, and risks of PAHs in vegetables and animal-based foods before and after grilling were investigated in this study. The sum of 16 (∑₁₆) PAH concentrations in grilled vegetables and grilled animal-based foods were 60.4-1936 and 69.1-4668 ng/g, respectively. Grilling markedly increased the ∑₁₆ PAH concentrations in most foods analyzed. Grilling clearly increased the low-molecular-weight PAH contributions to the ∑₁₆ PAH concentrations in vegetables but increased the heavier PAH contributions to the ∑₁₆ PAH concentrations in some animal-based foods. With the grilling, the total benzo[a]pyrene-equivalent concentrations of the 16 PAHs in Chinese chives and enoki mushrooms and most animal-based foods were improved significantly. Source assessments indicated that environmental sources contributed PAHs to the raw foods and high-temperature pyrolysis during grilling contributed large proportions of the PAHs in the grilled foods. The carcinogenic risks to humans from the exposure of PAHs in vegetables and animal-based foods were estimated. Grilling increased the total risks of PAHs in vegetables and animal-based foods by factors of 3.12 and 5.49, respectively. Total risks of PAHs in the 11 foods were 3.43 times higher when the foods were grilled than when raw. The results suggested that the negative effects of grilling on human health should be of great concern.

Polycyclic aromatic hydrocarbons in seasoned-roasted laver and their reduction according to the mixing ratio of seasoning oil and heat treatment in a model system

In food processing, polycyclic aromatic hydrocarbons (PAHs) can be generated during heat treatment, and the PAHs in seasoned-roasted (SR) laver can be reduced by checking points during manufacturing. Benzo (a) anthracene, chrysene, benzo (b) fluoranthene, and benzo (a) pyrene have been identified in SR laver via GC/MS. We confirmed that in practice, the PAHs in SR laver form from the mixed oil (57%) and roasting process (43%). To mitigate the formation of PAHs, we used a model system to change the mixing ratio of oil, roasting temperature, and time. A significant reduction (35%) was observed in the PAH level as the perilla oil was removed from the mixed oil composition and roasting continued at 350 °C for 10 s. These results show that the composition of the mixing oil and the parameters of the heat treatment are crucial factors that contribute to the formation of PAHs in roasted laver.

Effects of single and combined toxic exposures on the gut microbiome: Current knowledge and future directions

Human populations are chronically exposed to mixtures of toxic chemicals. Predicting the health effects of these mixtures require a large amount of information on the mode of action of their components. Xenobiotic metabolism by bacteria inhabiting the gastrointestinal tract has a major influence on human health. Our review aims to explore the literature for studies looking to characterize the different modes of action and outcomes of major chemical pollutants, and some components of cosmetics and food additives, on gut microbial communities in order to facilitate an estimation of their potential mixture effects. We identified good evidence that exposure to heavy metals, pesticides, nanoparticles, polycyclic aromatic hydrocarbons, dioxins, furans, polychlorinated biphenyls, and non-caloric artificial sweeteners affect the gut microbiome and which is associated with the development of metabolic, malignant, inflammatory, or immune diseases. Answering the question 'Who is there?' is not sufficient to define the mode of action of a toxicant in predictive modeling of mixture effects. Therefore, we recommend that new studies focus to simulate real-life exposure to diverse chemicals (toxicants, cosmetic/food additives), including as mixtures, and which combine metagenomics, metatranscriptomics and metabolomic analytical methods achieving in that way a comprehensive evaluation of effects on human health.

Effects of Phenolic Acid Marinades on the Formation of Polycyclic Aromatic Hydrocarbons in Charcoal-Grilled Chicken Wings

HIGHLIGHTS

PAH formation was more affected by marinating than by changing the grilling temperature. Inhibitory effects grew as the concentration of phenolic marinade increased within limits. The antiradical activity and the inhibition of PAHs formation have no direct relation.

Sensory and Consumer Evaluation of Smoked Pulled Pork Prepared Using Different Smokers and Different Types of Wood

Smoked and barbecued meats have continued to gain popularity in recent years, however, no consensus exists on the best methods for preparation. Several smoker types and many varieties of wood are used for smoking meat in the restaurant industry and by amateur "pit-masters." In this research, pork was smoked with an outdoor offset smoker and an indoor electric smoker using four wood types: hickory, apple, oak, and mesquite. Descriptive and consumer acceptance tests were conducted to evaluate the different treatments and determine drivers of liking. Pork smoked with the offset smoker using hickory wood had the highest overall acceptance. Appearance characteristics, such as intensity of red color, were the top drivers of liking for the smoked pork product. PRACTICAL APPLICATION: This research demonstrates the drivers of liking for smoked pork products commonly found in American barbecue, specifically Kansas City-style barbecue. The results have application in both retail and restaurant environments and can be used to produce an optimized smoked pork product.

Dietary Carcinogens and DNA Adducts in Prostate Cancer

Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer and the second leading cause of cancer-related to death in men. The major risk factors for PC are age, family history, and African American ethnicity. Epidemiological studies have reported large geographical variations in PC incidence and mortality, and thus lifestyle and dietary factors influence PC risk. High fat diet, dairy products, alcohol and red meats, are considered as risk factors for PC. This book chapter provides a comprehensive, literature-based review on dietary factors and their molecular mechanisms of prostate carcinogenesis. A large portion of our knowledge is based on epidemiological studies where dietary factors such as cancer promoting agents, including high-fat, dairy products, alcohol, and cancer-initiating genotoxicants formed in cooked meats have been evaluated for PC risk. However, the precise mechanisms in the etiology of PC development remain uncertain. Additional animal and human cell-based studies are required to further our understandings of risk factors involved in PC etiology. Specific biomarkers of chemical exposures and DNA damage in the prostate can provide evidence of cancer-causing agents in the prostate. Collectively, these studies can improve public health research, nutritional education and chemoprevention strategies.

Determination and risk characterization of polycyclic aromatic hydrocarbons of tea by using the Margin of Exposure (MOE) approach

Tea is one of the most frequently consumed drinks due to its favourite taste and the health benefit. Tea is produced by several processes and drying is very important step to develop the flavour and destroys the enzymes in tea. However, during drying tea, polycyclic aromatic hydrocarbons some of which are carcinogen and genotoxin are naturally produced. The risk of PAHs by drinking tea was characterized by determining contents of 4 PAHs in tea. 4 PAHs including Benz(a)anthracene (BaA), Chrysene (CHR), Benzo(b)fluoranthene (BbF) and Benzo(a)pyrene (BaP) were investigated by GC-MS in total 468 tea products, which were contaminated up to 4.63 ng g-1. Mate tea was the most highly contaminated by BaA, CHR, BbF and BaP and followed by Solomon's seal and Chrysanthemum. The Margin of Exposures calculated by the concentration of BaA, CHR, BbF and BaP and consumption amount of tea were higher than 10,000, and the risk of PAHs in tea were low concern to public health.

Occurrence, dietary exposure, and health risk estimation of polycyclic aromatic hydrocarbons in grilled and fried meats in Shandong of China

There is a lack of information regarding the quantitative determination and health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in grilled and fried meat products in Shandong Province of China. The aim of this work was firstly to detect the contamination levels of 15 PAHs in 52 grilled and fried meats consumed by the population of Shandong Province, China. In brief, concentrations of the sum of 15 PAHs in individual samples were ranged from 8.23 to 341 μg/kg with a mean contamination level of 63.3 μg/kg. Moreover, the factors for the formation of PAHs in these samples have been identified and analyzed. One grilled meat sample exceeded the maximum limits of 2 and 12 μg/kg set for BaP and PAH4 by the European Union. For a further step, the mean dietary exposures for total PAHs from grilled and fried meat products were estimated to be 120 and 74.8 ng/kg bw/day, respectively. Finally, the health risk estimation was performed using the incremental lifetime cancer risk (ILCR) approach. The obtained values of four groups were all lower than 10-4, indicating a slight potential carcinogenic risk of consumer health. This study was the first attempt to provide baseline information of potential health risk of dietary exposure of PAH-containing grilled and fried meats, which could be useful for health management of the local consumers.

Exploring the association between polycyclic aromatic hydrocarbons and diabetes among adults in the United States

OBJECTIVE

To explore the association between polycyclic aromatic hydrocarbons (PAHs) and diabetes and to determine whether effects are heterogeneous when examined by body mass index (BMI).

METHODS

Cross-sectional data from 8664 participants were analyzed from the National Health and Nutrition Examination Survey for years 2005-2014. Multivariable logistic regression was used to explore the association between urinary biomarkers of PAHs and diabetes. All models were adjusted for age, sex, race, poverty-income ratio, and serum cotinine.

RESULTS

When compared with the lowest quintiles of exposure, the highest quintiles of exposure to 2-hydroxynaphthalene, 2-hydroxyfluorene, 9-hydroxyfluorene, 2-hydroxyphenanthrene, and a summed variable of all low molecular weight PAHs (aOR = 1.73; 95% CI: 1.17-2.55) showed a positive association with diabetes. Stratified analyses by BMI indicated that the positive association between PAHs and diabetes was found among both normal weight and obese participants.

CONCLUSIONS

High levels of exposure to PAHs are positively associated with diabetes in the U.S. general population and these effects are modified by BMI. These findings suggest the importance of strong environmental regulation of PAHs to protect population health.

Domestic Cooking of Muscle Foods: Impact on Composition of Nutrients and Contaminants

Meat and fish are muscle foods rich in valuable nutrients, such as high-quality proteins, vitamins, and minerals, and, in the case of fish, also unsaturated fatty acids. The escalation of meat and fish production has increased the occurrence of pesticide and antibiotic residues, as result of pest control on feed crops, and antibiotics used to fight infections in animals. Meat and fish are usually cooked to enrich taste, soften texture, increase safety, and improve nutrient digestibility. However, the impact of cooking on nutritional properties and formation of deleterious compounds must be understood. This review summarizes studies, published in the last decade, that have focused on how domestic cooking affects: (i) composition of nutrients (protein, fatty acids, vitamins, and minerals); (ii) antibiotic and pesticide residue contents; and (iii) the formation of cooking-induced contaminants (heterocyclic aromatic amines, polycyclic aromatic hydrocarbons, and thermal degradation products of antibiotics and pesticides). Cooking affects the nutritional composition of meat and fish; frying is the cooking method that causes the greatest impact. Cooking may reduce the pesticide and antibiotic residues present in contaminated raw meat and fish; however, it may result in the formation of degradation products of unknown identity and toxicity. Control of cooking time and temperature, use of antioxidant-rich marinades, and avoiding the dripping of fat during charcoal grilling can reduce the formation of cooking-induced contaminants.

Environmental Pollutant Benzo[a]Pyrene Impacts the Volatile Metabolome and Transcriptome of the Human Gut Microbiota

Benzo[a]pyrene (B[a]P) is a ubiquitous, persistent, and carcinogenic pollutant that belongs to the large family of polycyclic aromatic hydrocarbons. Population exposure primarily occurs via contaminated food products, which introduces the pollutant to the digestive tract. Although the metabolism of B[a]P by host cells is well known, its impacts on the human gut microbiota, which plays a key role in health and disease, remain unexplored. We performed an in vitro assay using 16S barcoding, metatranscriptomics and volatile metabolomics to study the impact of B[a]P on two distinct human fecal microbiota. B[a]P exposure did not induce a significant change in the microbial structure; however, it altered the microbial volatolome in a dose-dependent manner. The transcript levels related to several metabolic pathways, such as vitamin and cofactor metabolism, cell wall compound metabolism, DNA repair and replication systems, and aromatic compound metabolism, were upregulated, whereas the transcript levels related to the glycolysis-gluconeogenesis pathway and bacterial chemotaxis toward simple carbohydrates were downregulated. These primary findings show that food pollutants, such as B[a]P, alter human gut microbiota activity. The observed shift in the volatolome demonstrates that B[a]P induces a specific deviation in the microbial metabolism.

Cooking Methods for Red Meats and Risk of Type 2 Diabetes: A Prospective Study of U.S. Women

OBJECTIVE

This study examined different cooking methods for red meats in relation to type 2 diabetes (T2D) risk among U.S. women who consumed red meats regularly (≥2 servings/week).

RESEARCH DESIGN AND METHODS

We monitored 59,033 women (1986-2012) aged 30-55 years and free of diabetes, cardiovascular disease, and cancer at baseline when information on frequency of different cooking methods for red meats, including broiling, barbequing, roasting, pan-frying, and stewing/boiling, was collected.

RESULTS

During 1.24 million person-years of follow-up, we documented 6,206 incident cases of T2D. After multivariate adjustment including red meat cooking methods, total red meat and processed red meat intake were both associated with a monotonically increased T2D risk (both P trend <0.05). After multivariate adjustment including total red meat intake, a higher frequency of broiling, barbequing, and roasting red meats was each independently associated with a higher T2D risk. When comparing ≥2 times/week with <1 time/month, the hazard ratios (HRs) and 95% CI of T2D were 1.29 (1.19, 1.40; P trend <0.001) for broiling, 1.23 (1.11, 1.38; P trend <0.001) for barbequing, and 1.11 (1.01, 1.23; P trend = 0.14) for roasting. In contrast, the frequency of stewing/boiling red meats was not associated with T2D risk, and an inverse association was observed for pan-frying frequency and T2D risk. The results remained similar after cooking methods were further mutually adjusted.

CONCLUSIONS

Independent of total red meat consumption, high-temperature and/or open-flame cooking methods for red meats, especially broiling and barbequing, may further increase diabetes risk among regular meat eaters.

Concentrations of environmental organic contaminants in meat and meat products and human dietary exposure: A review

Meat and meat products is one of the most relevant food groups in an important number of human diets. Recently, the IARC, based on results of a number of epidemiological studies, classified the consumptions of red meat and processed meat as "probably carcinogenic to humans" and as "carcinogenic to humans", respectively. It was suggested that the substances responsible of the potential carcinogenicity would be mainly generated during meat processing, such as curing and smoking, or when meat is heated at high temperatures. However, the exposure to environmental pollutants through meat consumption was not discussed. The purpose of the present paper was to review recent studies reporting the concentrations of PCDD/Fs, DL-PCBs and PAHs in meat and meat products, as well as the human exposure to these pollutants through the diet. It is concluded that the health risks derived from exposure to carcinogenic environmental contaminants must be considered in the context of each specific diet, which besides meat and meat products, includes other foodstuffs containing also chemical pollutants, some of them with carcinogenic potential. Anyhow, meat and meat products are not the main food group responsible of the dietary exposure to carcinogenic (or probably carcinogenic) environmental organic pollutants.

Presence and formation of fluorescence carbon dots in a grilled hamburger

Carbon nanoparticles in a grilled hamburger were discovered, which showed different structures and properties at various heating temperatures.