Effect of cooking time and temperature on the heterocyclic amine content of fried beef patties

Determination of Polar Heterocyclic Aromatic Amines in Meat Thermally Treated in a Roasting Bag with Dried Fruits

Frequent consumption of processed meat has been classified as carcinogenic to humans by the International Agency for Research on Cancer (Group 1), while red meat has been classified as probably carcinogenic (Group 2A). Mutagenic and carcinogenic compounds formed by heating in protein-rich food include, among others, heterocyclic aromatic amines (HAAs). Modifying the heat treatment of meat and using natural additives with antioxidant properties can lead to a reduction in their formation. The aim of this study was to determine polar HAAs (imidazoquinolines, IQ and MeIQ; imidazoquinoxalines, 8-MeIQx and 4,8-DiMeIQx; and phenylimidazopyridine, PhIP) in pork loin prepared without additives and with three types of dried fruit (apricots, cranberries, and prunes), baked in a roasting bag. HAAs were isolated from meat samples by solid-phase extraction. Quantitative analysis was performed by high-performance liquid chromatography with fluorescence detection (FLD) and a diode array detector (DAD). Only two HAAs, 8-MeIQx and PhIP, were detected in extracts isolated from meat samples. The total content of these compounds in meat roasted without additives was 5.9 ng/g. Using a dried fruit stuffing content of 200 g/kg of meat reduced these concentrations in dishes prepared with prunes, apricots, and cranberries by 42%, 47%, and 77%, respectively.

The Risk of Oral Cancer and the High Consumption of Thermally Processed Meat Containing Mutagenic and Carcinogenic Compounds

The International Agency for Research on Cancer has classified the consumption of heat-processed meat as a direct human carcinogen and the consumption of red meat as a probable carcinogen. Mutagenic and carcinogenic compounds present in meat dishes include, among others, polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HAAs). These compounds can cause the development of gastrointestinal cancer. Oral cancer is one of the world's research priorities due to the ever-increasing incidence rate. However, the effect of diet on oral cancer is still a poorly recognized issue. The aim of this study was to assess the relationship between the risk of oral cancer and dietary ingredients with a particular emphasis on red meat and thermally processed meat. This study was conducted among patients with oral cancer in 2022 and 2023. The shortened standardized Food Frequency Questionnaire (FFQ) and a multivariate regression statistical analysis were used. The high consumption of red meat in general and thermally processed meat, especially smoked, fried, roasted and boiled, increases the risk of oral cavity cancer. Limiting the consumption of meat products and modifying the methods of preparing meat dishes may reduce exposure to carcinogenic compounds from the diet and thus reduce the risk of developing oral cancer.

The Cooked Meat Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine Hair Dosimeter, DNA Adductomics Discovery, and Associations with Prostate Cancer Pathology Biomarkers

Well-done cooked red meat consumption is linked to aggressive prostate cancer (PC) risk. Identifying mutation-inducing DNA adducts in the prostate genome can advance our understanding of chemicals in meat that may contribute to PC. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a heterocyclic aromatic amine (HAA) formed in cooked meat, is a potential human prostate carcinogen. PhIP was measured in the hair of PC patients undergoing prostatectomy, bladder cancer patients under treatment for cystoprostatectomy, and patients treated for benign prostatic hyperplasia (BPH). PhIP hair levels were above the quantification limit in 123 of 205 subjects. When dichotomizing prostate pathology biomarkers, the geometric mean PhIP hair levels were higher in patients with intermediate and elevated-risk prostate-specific antigen values than lower-risk values <4 ng/mL (p = 0.03). PhIP hair levels were also higher in patients with intermediate and high-risk Gleason scores ≥7 compared to lower-risk Gleason score 6 and BPH patients (p = 0.02). PC patients undergoing prostatectomy had higher PhIP hair levels than cystoprostatectomy or BPH patients (p = 0.02). PhIP-DNA adducts were detected in 9.4% of the patients assayed; however, DNA adducts of other carcinogenic HAAs, and benzo[a]pyrene formed in cooked meat, were not detected. Prostate specimens were also screened for 10 oxidative stress-associated lipid peroxidation (LPO) DNA adducts. Acrolein 1,N²-propano-2'-deoxyguanosine adducts were detected in 54.5% of the patients; other LPO adducts were infrequently detected. Acrolein adducts were not associated with prostate pathology biomarkers, although DNA adductomic profiles differed between PC patients with low and high-grade Gleason scores. Many DNA adducts are of unknown origin; however, dG adducts of formaldehyde and a series of purported 4-hydroxy-2-alkenals were detected at higher abundance in a subset of patients with elevated Gleason scores. The PhIP hair biomarker and DNA adductomics data support the paradigm of well-done cooked meat and oxidative stress in aggressive PC risk.

Consumption of Thermally Processed Meat Containing Carcinogenic Compounds (Polycyclic Aromatic Hydrocarbons and Heterocyclic Aromatic Amines) versus a Risk of Some Cancers in Humans and the Possibility of Reducing Their Formation by Natural Food Additives-A Literature Review

(1) Background: Thermal treatment of high-protein food may lead to the formation of mutagenic and carcinogenic compounds, e.g., polycyclic aromatic hydrocarbons and heterocyclic aromatic amines. Frequent consumption of processed meat was classified by the International Agency for Research on Cancer as directly carcinogenic for humans. (2) Methods: A literature review was carried out based on a search of online databases for articles on consuming thermally processed meat containing carcinogenic compounds versus a risk of cancers in humans published between 2001 and 2021. (3) Results: A review of the current literature on the participation of PAHs and HAA in the formation of certain neoplasms indicates a positive relationship between diet and the incidences of many cancers, especially colon cancer. A simple way to obtain dishes with reduced contents of harmful compounds is the use of spices and vegetables as meat additives. These seasonings are usually rich in antioxidants that influence the mechanism of HAA and PAH synthesis in food. (4) Conclusions: As there is a growing risk of a cancer tendency because of exposing humans to PAHs and HAAs, it is extremely vital to find a simple way to limit carcinogenic compound synthesis in a processed proteinaceous food. Disseminating the knowledge about the conditions for preparing dishes with a reduced content of carcinogenic compounds could become a vital element of cancer prevention programs.

Red meat consumption, obesity, and the risk of nonalcoholic fatty liver disease among women: Evidence from mediation analysis

BACKGROUND

Previous studies have suggested consumption of red meat may be associated with an increased risk of developing nonalcoholic fatty liver disease (NAFLD). However, large-scale, prospective data regarding red meat consumption in relation to the incidence of NAFLD are lacking, nor is it known whether any association is mediated by obesity.

OBJECTIVE

We aimed to evaluate the relationship between red meat consumption and the subsequent risk of developing NAFLD.

DESIGN

This prospective cohort study included 77,795 women in the Nurses' Health Study II cohort without NAFLD at baseline (in 1995), who provided detailed, validated information regarding diet, including consumption of red meat, every 4 years, followed through 2015. Lifestyle factors, clinical comorbidities and body mass index (BMI), were updated biennially. Cox proportional hazard models were used to estimate multivariable adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Over 1,444,637 person years of follow-up, we documented 3130 cases of incident NAFLD. Compared to women who consumed ≤1 serving/week of red meat, the multivariable-adjusted HRs of incident NAFLD were 1.20 (95% CI: 0.97, 1.50) for 2-4 servings/week; 1.31 (95% CI: 1.06, 1.61) for 5-6 servings/week; 1.41 (95% CI: 1.13, 1.75) for 1 serving/day; and 1.52 (95% CI: 1.23, 1.89) for ≥2 servings/day. However, after further adjustment for BMI, all associations for red meat, including unprocessed and processed red meat, were attenuated and not statistically significant (all P-trend>0.05). BMI was estimated to mediate 66.1% (95% CI: 41.8%, 84.2%; P < 0.0001) of the association between red meat consumption and NAFLD risk.

CONCLUSIONS

Red meat consumption, including both unprocessed and processed red meat, was associated with significantly increased risk of developing NAFLD. This association was mediated largely by obesity.

Potential Role of Heterocyclic Aromatic Amines in Neurodegeneration

Heterocyclic aromatic amines (HAAs) are mainly formed in the pyrolysis process during high-temperature cooking of meat. Meat consumption is very typical of the western diet, and the amount of meat consumption in the eastern countries is growing rapidly; HAAs represents widespread exposure. HAAs are classified as possible human carcinogens; numerous epidemiological studies have demonstrated regular consumption of meat with HAAs as risk factor for cancers. Specific HAAs have received major attention. For example, 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine has been extensively studied as a genotoxicant and mutagen, with emergent literature on neurotoxicity. Harmane has been extensively studied for a role in essential tremors and potentially Parkinson's disease (PD). Harmane levels have been demonstrated to be elevated in blood and brain in essential tremor patients. Meat consumption has been implicated in the etiology of neurodegenerative diseases; however, the role of toxicants formed during meat preparation has not been studied. Epidemiological studies are currently examining the association between HAAs and risk of neurodegenerative diseases such as essential tremors and PD. Studies from our laboratory and others have provided strong evidence that HAA exposure produces PD and Alzheimer's disease-relevant neurotoxicity in cellular and animal models. In this review, we summarize and critically evaluate previous studies on HAA-induced neurotoxicity and the molecular basis of potential neurotoxic effects of HAAs. The available studies provide strong support for the premise that HAAs may impact neurological function and that addressing gaps in understanding of adverse neurological outcomes is critical to determine whether these compounds are modifiable risk factors.

Cooking Surface Temperatures, Steak Thickness, and Quality Grade Effects on Volatile Aroma Compounds

Volatile aroma compounds were evaluated in USDA Top Choice and Select beef top loin steaks cut 1.3 cm (THIN) or 3.8 cm (THICK) and cooked on a commercial flat top grill at 177°C (LOW) or 232°C (HIGH) grill surface temperature. Gas chromatography/mass spectrophotometry was used to evaluate volatile aroma compounds. USDA Select steaks had more 2-octene and less trimethyl pyrazine in (P &lt; 0.05) THIN steaks than THICK steaks, whereas Choice was unaffected by steak thickness (P &gt; 0.05). Benzene acetaldehyde was higher and 4-hydroxybenzoic acid was higher in Select LOW grill temperatures compared with Select HIGH grill temperatures, whereas 5-methyl-2-furan carboxaldehyde was only present in Choice HIGH grill temperatures (P &lt; 0.05). Two acids, 3 alcohols, 1 aldehyde, 1 alkane, and 1 ketone volatile aroma compound were higher (P &lt; 0.05) for LOW compared with HIGH. Conversely, 5 alcohols, 2 aldehydes, 2 alkanes, all 4 furans, 6 ketones, 4 pyrazines, along with 1H-indole, 2 pyrroles, 2 pyridines, and 1 benzene aroma compound were higher (P &lt; 0.05) in HIGH compared with LOW. Additionally, 1 alcohol, 2 aldehydes, 1 ketone, 1 sulfur-containing, and 6 other volatile compounds were lower, whereas 1 acid, 1 alcohol, 1 aldehyde, 2 furans, 1 ketone, 3 pyrazines, 1 sulfur-containing, and 1 other volatile compound were higher in the THIN compared with THICK. Some aroma compounds such as 2-butanone, 4-methyl-2-pentanone, 1-ethyl-1H-pyrrole, 1-methyl-1H-pyrrole, and 2-methyl-pyridine were only present in THICK cooked HIGH (P &lt; 0.05). Steak thickness and grill temperature are important factors to consider in the development of positive Maillard reaction products. Key findings are that high grill temperatures and/or thick steaks with longer grilling times are required for the development of key Maillard reaction products and many Maillard reaction products were only found in the most severe high-temperature, long-time grilling scenarios.

Formation and Prediction of PhIP, Harman, and Norharman in Chemical Model Systems Containing Epicatechin under Various Reaction Conditions

The aim of this study was to investigate the formation rules of 1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), 1-methyl-9H-pyrido[3,4-b]-indole (Harman), and 9H-pyrido[3,4-b]-indole (Norharman) in chemical model systems containing epicatechin under various reaction conditions and establish their prediction models. The results indicated that at 100-200 °C and pH 5.5-7.5 for 10-90 min, epicatechin inhibited the formation of PhIP, Harman, and Norharman by 32-100, 1-93, and 5-98%, respectively. The exponential growth equation in the growth model with R² of 0.986-0.997, the second-order equation in the polynomial model with R² of 0.900-0.949, and the trigonometric function equation in the Fourier model with R² of 0.513-0.926 were well fitted for the formation of PhIP, Harman, and Norharman at various temperatures, times, and pHs, respectively. The calibration set (R²c) and the prediction set (R²p) of the optimal partial least squares regression prediction model was 0.74 and 0.70 for PhIP, 0.75 and 0.70 for Harman, and 0.90 and 0.91 for Norharman, respectively. The results provide theoretical support to develop technologies or equipment for the real-time synchronous monitoring of PhIP, Harman, and Norharman during meat processing.

Detoxification of heterocyclic aromatic amines from grilled meat using a PEITC-rich vegetable sauce: a randomized crossover controlled trial

Heterocyclic aromatic amines (HAAs) including PhIP and MeIQx are potential carcinogens found mainly in well-done meat. Consuming brassica vegetables was shown to promote metabolisms of HAAs due to the action of isothiocyanates. Previous in vivo studies showed that phenethyl isothiocyanate (PEITC) was a potent stimulator of phase II detoxification enzymes. Nevertheless, the clinical effect of PEITC-rich vegetables on detoxification of HAAs in grilled meat was unknown. This research aimed to investigate the effect of a PEITC-rich vegetable sauce on the detoxification of HAAs in healthy people consuming grilled meat. A randomized crossover placebo-controlled trial was conducted in twenty-one healthy participants. They were randomly assigned into three groups. The participants consumed a single meal of grilled beef with 100 g of the placebo sauce and 100 g and 50 g of the vegetable sauce. All participants consumed all sauces in an alternating random sequence. After de-conjugation with β-glucuronidase, the HAA metabolites in urine were measured by using LC/MS-MS. Compared to the placebo sauce, consuming grilled beef with 100 g of the vegetable sauce increased the urinary excretion of both PhIP and MeIQx glucuronide metabolites (p-value <0.0001), while consuming 50 g of the sauce significantly increased only MeIQx metabolites (p-value <0.05). The findings of this study suggested that consuming grilled meat with 100 g of the PEITC-rich vegetable sauce could increase the urinary excretion of PhIP and MeIQx glucuronide metabolites. Since meat eaters usually consume a low amount of vegetables, the PEITC-rich vegetable sauce could be an alternative approach to provide detoxification benefits from vegetable-derived compounds.

Metabolism and biomarkers of heterocyclic aromatic amines in humans

Heterocyclic aromatic amines (HAAs) form during the high-temperature cooking of meats, poultry, and fish. Some HAAs also arise during the combustion of tobacco. HAAs are multisite carcinogens in rodents, inducing cancer of the liver, gastrointestinal tract, pancreas, mammary, and prostate glands. HAAs undergo metabolic activation by N-hydroxylation of the exocyclic amine groups to produce the proposed reactive intermediate, the heteroaryl nitrenium ion, which is the critical metabolite implicated in DNA damage and genotoxicity. Humans efficiently convert HAAs to these reactive intermediates, resulting in HAA protein and DNA adduct formation. Some epidemiologic studies have reported an association between frequent consumption of well-done cooked meats and elevated cancer risk of the colorectum, pancreas, and prostate. However, other studies have reported no associations between cooked meat and these cancer sites. A significant limitation in epidemiology studies assessing the role of HAAs and cooked meat in cancer risk is their reliance on food frequency questionnaires (FFQ) to gauge HAA exposure. FFQs are problematic because of limitations in self-reported dietary history accuracy, and estimating HAA intake formed in cooked meats at the parts-per-billion level is challenging. There is a critical need to establish long-lived biomarkers of HAAs for implementation in molecular epidemiology studies designed to assess the role of HAAs in health risk. This review article highlights the mechanisms of HAA formation, mutagenesis and carcinogenesis, the metabolism of several prominent HAAs, and the impact of critical xenobiotic-metabolizing enzymes on biological effects. The analytical approaches that have successfully biomonitored HAAs and their biomarkers for molecular epidemiology studies are presented.

Toxicology and Biodegradability of a Phthalate-Free and Bio-Based Novel Plasticizer

Phthalate esters, mainly di-ethylhexylphthalate (DEHP), represent a class of chemicals primarily used as plasticizers for polyvinyl chloride in a wide range of domestic and industrial applications. These phthalate esters are low-toxicity environmental contaminants. To address these drawbacks, POLYSORB® ID 37, a blend of diesters obtained from esterification of isosorbide with plant-based fatty acids, was developed. The company can now offer PVC manufacturers a new product which competes with phthalates and other such chemicals. The market for plasticizers is very important, and ROQUETTE intends to provide a more sustainable and safer product. Isosorbide diester is bio-based (made from glucose and vegetable fatty acids). This plasticizer is registered in REACH regulation for high volumes (>1000 T/year). Risk assessment was obtained by conducting a wide range of biodegradability and toxicological protocols, using rodent models, according to established guidelines. Overall, all of the toxicological and biodegradability studies demonstrated that POLYSORB® ID 37 is nontoxic to mammalian life and is readily biodegradable.

Heterocyclic Aromatic Amines in Meat: Formation, Isolation, Risk Assessment, and Inhibitory Effect of Plant Extracts

Heterocyclic aromatic amines (HAAs) are potent carcinogenic compounds induced by the Maillard reaction in well-done cooked meats. Free amino acids, protein, creatinine, reducing sugars and nucleosides are major precursors involved in the production of polar and non-polar HAAs. The variety and yield of HAAs are linked with various factors such as meat type, heating time and temperature, cooking method and equipment, fresh meat storage time, raw material and additives, precursor’s presence, water activity, and pH level. For the isolation and identification of HAAs, advanced chromatography and spectroscopy techniques have been employed. These potent mutagens are the etiology of several types of human cancers at the ng/g level and are 100- to 2000-fold stronger than that of aflatoxins and benzopyrene, respectively. This review summarizes previous studies on the formation and types of potent mutagenic and/or carcinogenic HAAs in cooked meats. Furthermore, occurrence, risk assessment, and factors affecting HAA formation are discussed in detail. Additionally, sample extraction procedure and quantification techniques to determine these compounds are analyzed and described. Finally, an overview is presented on the promising strategy to mitigate the risk of HAAs by natural compounds and the effect of plant extracts containing antioxidants to reduce or inhibit the formation of these carcinogenic substances in cooked meats.

Dynamic changes in the qualities and heterocyclic aromatic amines of roasted pork induced by frying temperature and time

The effects of different frying temperatures (150, 175, 200, 225 and 250 °C) and times (0.5, 1.0, 1.5, 2.0 and 2.5 min) on yield, shear force, color and sensory characteristics, and heterocyclic aromatic amine (HAA) contents of roasted pork were investigated. The results showed significant decreases in yield, shear force and L* and increases in a*, b* and the amounts of HAA of roasted pork with increased frying temperature and time (P < 0.05). The highest score of overall acceptability in crispy and darker roast pork fried at 225 °C for 1 min was obtained. However, the principal component analysis demonstrated that higher HAA contents of roasted pork under high frying temperature (225-250 °C) and long frying time (2-2.5 min) occurred. Considering the various qualities and the amounts of HAA, frying roasted pork at 175 °C for 1.5-2 min was the most suitable condition for preparing roasted pork.

Evaluating the effects of temperature and time on heterocyclic aromatic amine profiles in roasted pork using combined UHPLC-MS/MS and multivariate analysis

In this study, ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) combined with principal component analysis (PCA) were used to investigate the effects of process conditions on the profiles of carcinogenic and mutagenic heterocyclic aromatic amine (HAA) in the pork roasted at 175 °C, 200 °C, 225 °C and 250 °C for 10, 15, 20, 25, 30, 35 and 40 min. Twelve HAAs from four categories, including carboline (Norharman, Harman, and Phe-p-1), imidazopyridine (PhIP, 4'-OH-PhIP, DMIP, and 1,5,6-TMIP), imidazoquinoline (IQ, IQ [4,5-b], and MeIQ), and imidazoquinoxaline (MeIQx and 4,8-DiMeIQx), were detected, quantified and used to compose the HAA profiles in roasted pork. After being Analyzed by PCA, the distributions of HAA profiles from different temperature on the PCA score plot demonstrated that there are significant differences among the HAA profiles from different temperatures. The loading plot also showed that PhIP, 4'-OH-PhIP, IQ[4,5-b], and MeIQ were mainly responsible for the difference. The profiles from higher temperature distribute more scattered than the lower ones, illustrating that the time effects on the HAA profiles from higher temperature are stronger than the lower ones. Comparing the score and loading plots of different heating times, the diversities of the HAA profiles at different temperatures increased under prolonged heating because of the changingpyridines levels. The results of PCA that comparing the HAA from different categories displayed that the formation features of four categories HAAs were significantly differed because of their formation discrepancy under low temperatures and short-term roasting. Using HAA profiles as an entirety, these findings obtained in this study are more close to the real process of HAA formation in roasted pork, and make the complex effects of temperature and time on multiple HAA formations more simply to be concluded.

Potential of Chlorella as a Dietary Supplement to Promote Human Health

Chlorella is a green unicellular alga that is commercially produced and distributed worldwide as a dietary supplement. Chlorella products contain numerous nutrients and vitamins, including D and B12, that are absent in plant-derived food sources. Chlorella contains larger amounts of folate and iron than other plant-derived foods. Chlorella supplementation to mammals, including humans, has been reported to exhibit various pharmacological activities, including immunomodulatory, antioxidant, antidiabetic, antihypertensive, and antihyperlipidemic activities. Meta-analysis on the effects of Chlorella supplementation on cardiovascular risk factors have suggested that it improves total cholesterol levels, low-density lipoprotein cholesterol levels, systolic blood pressure, diastolic blood pressure, and fasting blood glucose levels but not triglycerides and high-density lipoprotein cholesterol levels. These beneficial effects of Chlorella might be due to synergism between multiple nutrient and antioxidant compounds. However, information regarding the bioactive compounds in Chlorella is limited.

PhIP exposure in rodents produces neuropathology potentially relevant to Alzheimer's disease

Alzheimer's disease (AD) is a public health crisis due to debilitating cognitive symptoms and lack of curative treatments, in the context of increasing prevalence. Thus, it is critical to identify modifiable risk factors. High levels of meat consumption may increase AD risk. Many toxins are formed during meat cooking such as heterocyclic aromatic amines (HAAs). Our prior studies have shown that HAAs produce dopaminergic neurotoxicity. Given the mechanistic and pathological overlap between AD and dopaminergic disorders we investigated whether exposure to 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP), a prevalent dietary HAA formed during high-temperature meat cooking, may produce AD-relevant neurotoxicity. Here, C57BL/6 mice were treated with 100 or 200 mg/kg PhIP for 8 h or 75 mg/kg for 4 weeks and 16 weeks. PhIP exposure for 8 h produced oxidative damage, and AD-relevant alterations in hippocampal synaptic proteins, Amyloid-beta precursor protein (APP), and β-Site amyloid precursor protein cleaving enzyme 1 (BACE1). PhIP exposure for 4 weeks resulted in an increase in BACE1. PhIP exposure for 16 weeks resulted in increased hippocampal oxidative damage, APP, BACE1, Aβ aggregation, and tau phosphorylation. Quantification of intracellular nitrotyrosine revealed oxidative damage in cholinergic neurons after 8 h, 4 weeks and 16 weeks of PhIP exposure. Our study demonstrates that increase in oxidative damage, APP and BACE1 might be a possible mechanism by which PhIP promotes Aβ aggregation. Given many patients with AD or PD exhibit neuropathological overlap, our study suggests that HAA exposure should be further studied for roles in mediating pathogenic overlap.

Detoxification of Heterocyclic Aromatic Amines by Probiotic to Inhibit Medical Hazards

Cancer is the second leading factor of human death in the world. Long-term consumption of cooked red meat brings about various types of cancers like colorectal cancer due to the formation of Heterocyclic Aromatic Amines (HAAs) during the heating process of meat. There are various solutions for the reduction of these toxicants. The aim of this article is to describe probiotic as one of the possible strategies for bioremoval of these carcinogenic and mutagenic substances and change food to functional one as well. The mechanism of biodetoxification is binding by probiotics, which depends on some variables including the probiotic characteristics, kind and content of the mutagens, as well as some properties of media. In this article, after introducing detoxification ability of probiotics and listing of all reported probiotics in this field, the influencing variables are surveyed and finally, opportunities and problems of HAA bioremoval by probiotics are described.

Inhibitory effects of black cumin on the formation of heterocyclic aromatic amines in meatball

The impact of black cumin usage on some qualitative properties and formation of heterocyclic aromatic amines (HAAs) in meatball production was investigated. It was found that black cumin usage rate, cooking process and temperature had a significant effect (p<0,01) on the water content, pH, and thiobarbituric acid reactive substances (TBARS) values of meatballs. On the other hand, black cumin usage significantly (p<0,01) reduced the water content and cooking loss. The water content and cooking loss of the meatballs decreased with increases in the usage rate. While IQx, IQ, MeIQ, 7,8-DiMeIQx, 4,8-DiMeIQx, AαC, and MeAαC could not be detected in meatballs, varying amounts of MeIQx (up to 1,53 ng/g) and PhIP (up to 1,22 ng/g) were determined. The total amounts of HAAs ranged between non-detected (nd) to 2,75 ng/g. Both the usage rate and cooking temperature had a very significant effect (p<0,01) on the total contents of HAAs. The total amounts of HAAs were decreased in correlation with the increases in the usage rate; the proportion which is increased when the cooking temperature increased as well. Results of the present study suggested that addition of black cumin may have a substantial role in decreasing the TBARS value, cooking loss, and HAA contents during meatball production. Therefore, using of black cumin in meatball production has been suggested.

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.

Ruminant meat flavor influenced by different factors with special reference to fatty acids

Ruminant meat flavor is an important quality and sensory parameter which relays mainly on the organoleptic characteristics of meat. Meat flavor is vital factor for the palatability and acceptability of meat by the consumers. There are various intrinsic and extrinsic factors that influence eating quality of meat. Among these factors, flavor is the major contributor. Fat and low-molecular-weight water-soluble compounds are the most important precursor components in meat, responsible for the meat flavor. The present review focus on the different pre and post-harvest factors that influences the ruminant meat flavor. Raw meat has little flavor but cooking adds value in flavor due to different temperature and cooking methods. The volatile flavoring compounds which are responsible for cooked meat flavor are produced thermally by the Maillard's reaction itself or interaction with lipid oxidation products and vitamin degradation. In nutshell, this review provides perception into previous literature on flavor that affected by various factors particularly the fatty acids and cooking methods.

Meat Cooking Methods and Risk of Type 2 Diabetes: Results From Three Prospective Cohort Studies

OBJECTIVE

To examine open-flame and/or high-temperature cooking (grilling/barbecuing, broiling, or roasting) and doneness preferences (rare, medium, or well done) for red meat, chicken, and fish in relation to type 2 diabetes (T2D) risk among U.S. adults who consumed animal flesh regularly (≥2 servings/week).

RESEARCH DESIGN AND METHODS

The prospective studies included 52,752 women from the Nurses' Health Study (NHS) (followed during 1996-2012), 60,809 women from NHS II (followed during 2001-2013), and 24,679 men from the Health Professionals Follow-Up Study (HPFS) (followed during 1996-2012) who were free of diabetes, cardiovascular disease, and cancer at baseline. Incident cases of T2D were confirmed by validated supplementary questionnaires.

RESULTS

We documented 7,895 incident cases of T2D during 1.74 million person-years of follow-up. After multivariate adjustments including baseline BMI and total consumption of red meat, chicken, and fish, higher frequency of open-flame and/or high-temperature cooking was independently associated with an elevated T2D risk. When comparing open-flame and/or high-temperature cooking >15 times/month with <4 times/month, the pooled hazard ratio (HR) (95% CI) of T2D was 1.28 (1.18, 1.39; Ptrend <0.001). When comparing the extreme quartiles of doneness-weighted frequency of high-temperature cooking, the pooled HR (95% CI) of T2D was 1.20 (1.12, 1.28; Ptrend <0.001). These associations remained significant when red meat and chicken were examined separately. In addition, estimated intake of heterocyclic aromatic amines was also associated with an increased T2D risk.

CONCLUSIONS

Independent of consumption amount, open-flame and/or high-temperature cooking for both red meat and chicken is associated with an increased T2D risk among adults who consume animal flesh regularly.

Probabilistic estimates of heterocyclic amines and polycyclic aromatic hydrocarbons concentrations in meats and breads applicable to exposure assessments

Random effect meta-regressions were constructed to estimate concentrations of two heterocyclic amines (HCA) and eight polycyclic aromatic hydrocarbons (PAH) in meat and breads. Eighteen HCA studies and nine PAH studies of food concentration were assembled. Concentration was computed for beef, poultry, pork, and seafood, and bread. Fixed effect predictors included cooking time, form of the food, cooking method, interaction between form and cooking method, temperature at which the food was cooked, fuel of the flame source, percentage of fat, and other elements. Meat type was significant to all HCAs but only three of the PAHs. Cooking method or an interaction between cooking method and food form was significant in all the overall models for each compound, and 80% of models created for stratifications of the data based on meat type. Improvement on compilations such as the Computerized Heterocyclic Amines Resource for Research in Epidemiology of Disease (CHARRED) database comes from inclusion of additional studies, PAH compounds, more generalizable food categories, more cooking methods (such as smoking), and addition of seafood. Meta-regression allows parameters to be estimated with separation of between-study heterogeneity, and extrapolation of exposures to more foods. Resulting uncertainty estimates are useful in a probabilistic exposure assessment.

Alterations in the nigrostriatal dopamine system after acute systemic PhIP exposure

Heterocyclic amines (HCAs) are primarily formed during cooking of meat at high temperature. HCAs have been extensively studied as mutagens and possible carcinogens. Emerging data suggest that HCAs are neurotoxic and may be relevant to Parkinson's disease (PD) etiology. However, the majority of HCAs have not been evaluated for in vivo neurotoxicity. Here, we investigated acute in vivo neurotoxicity of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). PhIP is the most prevalent genotoxin in many types of meats. Adult, male Sprague-Dawley rats were subjected to acute, systemic PhIP at doses and time-points that have been extensively utilized in cancer studies (100 and 200 mg/kg for 8, 24 h) and evaluated for changes in dopaminergic, serotoninergic, GABAergic, and glutamatergic neurotransmission. PhIP exposure resulted in decreased striatal dopamine metabolite levels and dopamine turnover in the absence of changes to vesicular monoamine transporter 2 levels; other neurotransmitter systems were unaffected. Quantification of intracellular nitrotyrosine revealed higher levels of oxidative damage in dopaminergic neurons in the substantia nigra after PhIP exposure, while other neuronal populations were less sensitive. These changes occurred in the absence of an overt lesion to the nigrostriatal dopamine system. Collectively, our study suggests that acute PhIP treatment in vivo targets the nigrostriatal dopaminergic system and that PhIP should be further examined in chronic, low-dose studies for PD relevance.

Dual Effects of Creatinine on the Formation of 2-Amino-1-Methyl-6-Phenylimidazo [4,5-b]pyridine (PhIP)

Creatinine was found to not only act as a precursor of 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) formation but also inhibit PhIP formation in a creatinine/phenylalanine model system. The dual mechanistic effects of creatinine on PhIP formation were then investigated in a model system. Adducts of creatinine-PhIP were detected by quadrupole-time-of-flight mass spectrometry and were found to be a likely explanation for the substantial decrease in the yield of PhIP when excess creatinine was supplied. Structures of probable adducts were predicted in molecular docking studies, which showed that hydrogen bonds were formed between creatinine and PhIP in 1:1 and 2:1 ratios. Furthermore, the active sites during creatinine-PhIP adduct formation (the primary amino groups [N² -] and sp² nitrogen atoms [N³ ] of creatinine and PhIP) match the active sites of PhIP metabolism and adducts of PhIP/lipid-derived reactive carbonyls. This verifies that creatinine inhibits PhIP production via the formation of adducts with hydrogen bonds at the N² and N³ sites.

PRACTICAL APPLICATION

This study enhances the understanding of how creatinine affects PhIP formation, reveals a new PhIP inhibition mechanism, and will be useful for developing technology to control PhIP formation during food processing.

Polysaccharides Reduce Absorption and Mutagenicity of 3-Amino-1,4-Dimethyl-5H-Pyrido[4,3-b]Indole In Vitro and In Vivo

3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) is a group 2B carcinogen characterized by the International Agency for Research on Cancer (IARC) and great efforts have been taken to reduce Trp-P-1 mutagenicity to humans. In this study, the effect of a reduction of Trp-P-1 on intestinal absorption as a promising strategy was investigated. The data showed that when 20 mM Trp-P-1 cotransported with 10 mM of sodium carboxymethyl cellulose (CMC), xanthan gum, or carrageenan, the absorption rate of Trp-P-1 was reduced by 31.5%, 49.5%, or 72.9% in MDCK-MDR1 cell monolayer, respectively; and 64.6%, 83.4%, or 64.1% in rat intestinal tissues, correspondingly. These 3 polysaccharides also reduced pharmacokinetic parameters, that is, C_max , AUC_0-t , and AUC_0-∞ , after Trp-P-1 was given to rats intragastrically. However, gum arabic did not exhibit similar effects on Trp-P-1 absorption in vitro or in vivo. The Ames test showed that these 3 polysaccharides reduced Trp-P-1 mutagenicity to Salmonella typhimurium TA98, but gum arabic did not. Isothermal titration calorimetry assay indicated that Trp-P-1 interacted with these 3 polysaccharides. Thermodynamic study showed that the actual value of △H <0, but its absolute value greater than the corresponding value of T∆S, suggest a specific interaction between Trp-P-1 and these 3 polysaccharides, probably through the hydrogen bond and/or ion interaction. Reduction of Trp-P-1 intestinal absorption using food additives could be one of the strategies to suppress Trp-P-1-induced carcinogenesis in human.

PRACTICAL APPLICATION

1.This study provides insightful information for the food industry how gum arabic, xanthan gum, kappa carrageenan, and sodium carboxymethyl cellulose affect the absorption of Trp-P-1. 2.This study also provides novel information regarding a better formulation for meat products to reduce Trp-P-1 absorption.

The effects of different spices and fat types on the formation of heterocyclic aromatic amines in barbecued sucuk

BACKGROUND

Sucuk is one of the popular traditional Turkish meat products. The aim of this research was to evaluate the effects of different spices (clove, 0.2%; cinnamon, 0.5%) and animal fat types (beef fat, tallow, subcutaneous and tail fat) on the formation of heterocyclic aromatic amine (HCA) in barbecued sucuk.

RESULTS

Although 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAαC) could not be detected in the any of the samples, 2-amino-3-methylimidazo[4,5-f]quinoxaline (IQx) (up to 0.54 ng g^-1 ), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) (up to 5.96 ng g^-1 ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (up to 0.21 ng g^-1 ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) (up to 0.34 ng g^-1 ), 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx) (up to 0.32 ng g^-1 ), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) (up to 0.19 ng g^-1 ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (up to 1.94 ng g^-1 ) and 2-amino-9H-pyrido[2,3-b]indole (AαC) (up to 0.98 ng g^-1 ) were found in the barbecued sucuk samples.

CONCLUSION

The results of the current study have shown that HCAs could be formed in barbecued sucuk. Total HCA can be affected by adding different fat types; however, adding clove and cinnamon decreased the total HCA content in the subcutaneous fat group of sucuk samples. © 2017 Society of Chemical Industry.

Metabolism of Foodborne Heterocyclic Aromatic Amines by Lactobacillus reuteri DSM 20016

The heterocyclic aromatic amine (HAA) 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is converted into 7-hydroxy-5-methyl-3-phenyl-6,7,8,9-tetrahydropyrido[3',2':4,5]imidazo[1,2-a]pyrimidin-5-ium chloride (PhIP-M1) via a chemical reaction with 3-hydroxypropionaldehyde or acrolein derived from glycerol by reuterin producing gut bacteria. Because it is unknown whether this reaction also applies to other HAAs, seven foodborne HAAs (2-amino-9H-pyrido[2,3-b]indole (AαC), 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethyl-3H-imidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethyl-3H-imidazo[4,5-f]quinoxaline (MeIQx), 9H-pyrido[3,4-b]indole (norharman), and 1-methyl-9H-pyrido[3,4-b]indole (harman)) were anaerobically incubated with Lactobacillus reuteri DSM 20016 in the presence of glycerol. The extent of conversion, as analyzed by HPLC-DAD/FLD, was dependent on both the studied HAAs and the glucose/glycerol ratio, indicating reuterin to be involved in HAA metabolism. Based on HRMS analyses, PhIP-M1-type metabolites were detected for AαC, Trp-P-1, IQ, MeIQ, MeIQx, harman, and norharman. In the case of AαC, this was confirmed by metabolite isolation (AαC-M8, 2,3,4,10-tetrahydro-1H-indolo[2,3-b][1,8]naphthyridin-2-ol) and one- (¹H) and two-dimensional (HSQC, HMBC, COSY, DOSY) NMR spectroscopy. In addition, based on HRMS and/or NMR spectroscopy, a new type of HAA metabolite, resulting from the reaction with two molecules of 3-hydroxypropionaldehyde or acrolein, is hypothesized for AαC, Trp-P-1, IQ, MeIQ, and MeIQx.

Inhibitory effect of hawthorn extract on heterocyclic aromatic amine formation in beef and chicken breast meat

This study focused on the inhibitory effect of different levels of hawthorn extract (0, 0.5, and 1%) on the formation of heterocyclic aromatic amines (HAAs) in beef and chicken breast cooked by either pan-cooking or oven-cooking. All meat samples were cooked at three different temperatures (150, 200, and 250°C) and the levels of twelve HAAs were assessed (IQ, IQx, MeIQ, MeIQx, 4,8-DiMeIQx, 7,8-DiMeIQx, PhIP, harman, norharman, AαC, MeAαC, and Trp-P-2). Varying levels of IQ (up to 4.47ng/g), IQx (up to 0.69ng/g), MeIQ (up to 0.82ng/g), MeIQx (up to 1.01ng/g), 4,8-DiMeIQx (up to 0.10ng/g), 7,8-DiMeIQx (up to 0.23ng/g), PhIP (up to 0.75ng/g), harman (up to 2.15ng/g), norharman (up to 1.08ng/g), AαC (up to 1.86ng/g), MeAαC (up to 0.48ng/g), and Trp-P-2 (up to 12.88ng/g), were detected. Samples cooked at 150°C had very low amounts of HAAs, and the levels of HAAs increased gradually when the cooking temperature rose from 150 to 250°C. The total HAA content in chicken breast and beef ranged between not detectable to 17.60ng/g, and not detectable to 11.38ng/g, respectively. The inhibitory effects of hawthorn extract at 0.5% and 1% on total HAAs levels were found to be 12-100% and 19-97% in chicken breast, respectively, and 42-100% and 20-35% in beef, respectively. This study demonstrated that hawthorn extracts at 0.5% and 1% could mitigate HAA formation, especially at high cooking temperatures.

Formation of Free and Protein-Bound Heterocyclic Amines in Roast Beef Patties Assessed by UPLC-MS/MS

The effect of different roasting temperatures on the amounts of 17 heterocyclic amines (HAs) from seven categories of both free and protein-bound states in roast beef patties was assessed using an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. There were increased amounts and more types of HAs detected at higher roasting temperatures. Nine free HAs were detected at 250 °C, including PhIP (14.34 ± 0.36 ng/g), DMIP (1.02 ± 0.07 ng/g), 1,5,6-TMIP (1.70 ± 0.08 ng/g), MeIQ (0.36 ± 0.01 ng/g), IQx (0.37 ± 0.04 ng/g), MeIQx (9.94 ± 0.61 ng/g), 4,8-DiMeIQx (0.90 ± 0.05 ng/g), norharman (6.03 ± 0.30 ng/g), and harman (2.60 ± 0.09 ng/g). Also, 37.32 ng/g of total free HAs was generated. Twelve protein-bound HAs were detected in roast beef patties at 250 °C, including PhIP (1.70 ± 0.13 ng/g), DMIP (2.33 ± 0.25 ng/g), 1,5,6-TMIP (3.62 ± 0.49 ng/g), MeIQ (5.47 ± 0.18 ng/g), IQ[4,5-b] (0.70 ± 0.03 ng/g) MeIQx (4.03 ± 0.41 ng/g), 4,8-DiMeIQx (0.67 ± 0.09 ng/g), MeAαC (19.51 ± 1.12 ng/g), AαC (2.91 ± 0.45 ng/g), norharman (1304.96 ± 110.73 ng/g), harman (400.85 ± 25.29 ng/g), and Phe-P-1 (0.81 ± 0.06 ng/g). The highest amount of protein-bound HAs was 2913.31 ng/g at 175 °C. PhIP tended to exist in a free state, whereas MeIQ, harman, and norharman tended to exist in a protein-bound state. Furthermore, Phe-P-1, MeAαC, and AαC were detected only in a protein-bound state. These results could be useful for evaluating the exposure to HAs in a daily diet.

Presence of heterocyclic amine carcinogens in home-cooked and fast-food camel meat burgers commonly consumed in Saudi Arabia

Heterocyclic amines (HCAs) are formed by cooking protein-rich foods, for instance, meat and fish, and are listed as possible human carcinogens. In the present study, the presence of five potential HCAs (IQ, MeIQ, MeIQx, 4,8-DiMeIQx, and PhIP) in cooked camel meat burgers was analyzed for the first time. The analysis was performed in home-cooked and fast-food burger samples containing food additives. The applied cooking technique for the home-cooked samples was pan frying for a controlled cooking time and temperature. In the control cooked meat samples (samples that contained no food additives), the concentrations of MeIQx, 4,8-DiMeIQx, and PhIP ranged from 2.47 ng/g to 4.89 ng/g, whereas IQ and MeIQ were found to be below the limit of quantification. The concentrations contents of MeIQx, 4,8-DiMeIQx, and PhIP in the home-cooked and fast-food samples ranged from 1.52 ng/g to 2.13 ng/g and 1.85 ng/g to 3.46 ng/g, respectively. IQ and MeIQ were not detected in either type of sample. In comparison to the control samples, the home-cooked and fast-food samples produced lower levels of HCAs. Such observations could result from the existence of antioxidants in incorporated food additives, which induce pro-oxidative effects with the successive formation and/or scavenging of free radicals.

Mass Spectrometric Characterization of an Acid-Labile Adduct Formed with 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and Albumin in Humans

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a carcinogenic heterocyclic aromatic amine formed during the high-temperature cooking of meats. The cytochrome P450-mediated N-hydroxylation of the exocyclic amine group of PhIP produces 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine, an electrophilic metabolite that forms adducts with DNA and proteins. Previous studies conducted by our laboratory showed that the reaction of N-oxidized PhIP metabolites with human albumin in vitro primarily occurs at the Cys³⁴ residue, to produce an acid-labile linked sulfinamide adduct. On the basis of these findings, we developed a sensitive ultraperformance liquid chromatography-mass spectrometry method to measure acid-labile albumin-PhIP adducts in human volunteers administered a dietary-relevant dose of ¹⁴C-labeled PhIP [Dingley, K. H., et al. (1999) Cancer Epidemiol., Biomarkers Prev. 8, 507-512]. Mild acid treatment of albumin (0.1 N HCl, 37 °C for 1 h) or proteolytic digestion with Pronase [50 mM ammonium bicarbonate buffer (pH 8.5) at 37 °C for 18 h] released similar amounts of covalently bound PhIP, which was characterized by multistage scanning and quantified by Orbitrap mass spectrometry. The amount of [¹⁴C]PhIP recovered by acid treatment of albumin 24 h following dosing accounted for 7.2-21.3% of the [¹⁴C]PhIP bound to albumin based on accelerator mass spectrometry measurements. 2-Amino-1-methyl-6-(5-hydroxy)phenylimidazo[4,5-b]pyridine, a hydrolysis product of the Cys³⁴ S-N linked sulfenamide adduct of PhIP, was not detected in either acid-treated or protease-treated samples. These findings suggest that a portion of the PhIP bound to albumin in vivo probably occurs as an acid-labile sulfinamide adduct formed at the Cys³⁴ residue.

Cooking methods and the formation of PhIP (2-Amino, 1-methyl, 6-phenylimidazo[4,5-b] pyridine) in the crust of the habitually consumed meat in Argentina

Content of carcinogenic molecules like, 2-Amino, 1-methyl, 6-phenylimidazo[4,5-b] pyridine in meals is one of the main mutagenic substances formed during meat cooking, and it can be used as a dietary exposure marker. Our objective was to estimate the amount of PhIP consumed from habitual Argentinean diet, rich in red meats, comparing different cooking procedures and meat type. Samples (n = 240) of lean and fatty beef, chicken, pork, and fish were cooked using different methods: griddle, grill, sauté pan, and oven. Samples were: Overcooked, or cooked with a microbiologically suitable or "healthy technique" (HT). The PhIP was determined by HPLC-MS. Meats cooked using HT formed little crust amounts and PhIP was below the detection levels. In overcooked meats, large amounts of crust were formed in lean meats, fatty beef, fatty chicken and baked pork. PhIP was measured in lean meats sauted or cooked on a griddle, a method reaching temperatures until 250 °C.It was estimated that Argentine people eats about 12,268.0 ng/day of PhIP being these values above those tolerated limits for total dietary heterocyclic amines in some developed countries. Hence, cooking small meat portions, at medium temperature, avoiding prolonged cooking and preferring baked lean meats could be recommended as a healthier habit.

Inhibitory Effect of Rosa rugosa Tea Extract on the Formation of Heterocyclic Amines in Meat Patties at Different Temperatures

In previous studies, heterocyclic amines (HCAs) have been identified as carcinogenic and a risk factor for human cancer. Therefore, the present study was designed to identify bioactive natural products capable of controlling the formation of HCAs during cooking. For this purpose we have evaluated the effect of Rosa rugosa tea extract (RTE) on the formation of HCAs in ground beef patties fried at 160 °C or 220 °C. RTE is rich in phenolic compounds and capable of inhibiting the formation of free radicals. The pyrido[3,4-b]indole (norharman) and 1-methyl-9H-pyrido[3,4-b]indole (harman) contents were significantly (p < 0.05) decreased in RTE-treated patties at 220 °C. 9H-3-Amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2) and 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole acetate (Trp-P-1) were not detected at 160 °C and were statistically (p < 0.01) reduced at 220 °C compared to the control. RTE remarkably inhibited the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) at 220 °C (p < 0.001) and at 160 °C (p < 0.05). 2-Amino-9H-pyrido[2,3-b]indole (AαC) and 2-amino-3-methyl-9H-pyrido[2,3-b]-indole (MeAαC) were only detected in the control group at 160 °C but were comparatively (p > 0.05) similar in the control and treated groups at 220 °C. 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-3,4,8-trimethylimidazo[4,5-f]-quinoxaline (4,8-DiMeIQx) were not detected in any sample. Total HCAs were positively correlated with cooking loss. In the RTE-treated groups, 75% of the total HCAs were decreased at 160 °C and 46% at 220 °C, suggesting that RTE is effective at both temperatures and can be used during cooking at high temperatures to lessen the amount of HCAs formed.

Heterocyclic Aromatic Amines in Cooked Meat Products: Causes, Formation, Occurrence, and Risk Assessment

Meat products are sources of protein with high biological value and an essential source of other nutrients, such as vitamins and minerals. Heating processes cause food to become more appetizing with changes in texture, appearance, flavor, and chemical properties by the altering of protein structure and other ingredients. During heat treatment, heterocyclic aromatic amines (HAAs), potent mutagens/carcinogens, are formed due to the Maillard reaction. The HAAs are classified in at least 2 groups: thermic HAAs (100 to 300 °C) and pyrolytic HAAs (>300 °C). This review focuses on the parameters and precursors which affect the formation of HAAs: preparation, such as the marinating of meat, and cooking methods, including temperature, duration, and heat transfer, as well as levels of precursors. Additionally, factors are described subject to pH, and the type of meat and ingredients, such as added antioxidants, types of carbohydrates and amino acids, ions, fat, and other substances inhibiting or enhancing the formation of HAAs. An overview of the different analytical methods available is shown to determine the HAAs, including their preparation to clean up the sample prior to extraction. Epidemiological results and human daily intake of HAAs obtained from questionnaires show a relationship between the preference for very well-done meat products with increased HAA levels and an enhanced risk of the incidence of cancer, besides other carcinogens in the diet. The metabolic pathway of HAAs is governed by the activity of several enzymes leading to the formation of DNA adducts or HAA excretion and genetic sensitivity of individuals to the impact of HAAs on human cancer risk.