Heterocyclic aromatic amines in fried poultry meat

 Heterocyclic aromatic amines are mutagenic compounds that are formed during heating of meat and fish. These substances are products of the reaction of creatine with amino acids and carbohydrates. It is recommended that exposure to these probable human carcinogens should be minimised. In fried boneless lean turkey breast meat five heterocyclic aromatic amines {2-amino-1-methyl-imidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethyl-imidazo-[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethyl-imidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethyl-imidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)} were found. The temperature regime which was applied for frying resulted in a surface temperature of about 140°C. Clean-up was done by acid-base partition followed by solid-phase extraction (SPE) using blue cotton. HPLC analysis was carried out using electrochemical detection for IQ- and IQx-type compounds and fluorescence detection for PhIP. The low temperatures used during frying yielded comparably lower amounts of heterocyclic aromatic amines. The concentrations of the aromatic amines were as follows: IQ 1.1 μg/kg, MeIQ 0.9 μg/kg, MeIQx μg/kg, 4,8-DiMeIQx 0.4 μg/kg, and PhIP 3.8 μg/kg. Received: 19 February 1997 / Revised version: 21 April 1997     

Dietary exposure to heterocyclic amines in high-temperature cooked meat and fish in Malaysia

The intake of heterocyclic amines is influenced by the amount and type of meat and fish ingested, frequency of consumption, cooking methods, cooking temperature, and duration of cooking. In this study, the dietary intake of heterocyclic amines in Malaysia and their main sources were investigated. Forty-two samples of meat and fish were analysed by high-performance liquid chromatography with photodiode array detector to determine the concentration of the six predominant heterocyclic amines, namely: 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), 2-amino-3,4,8-trimethylimidazo[4,5-f] quinoxaline (4,8-DiMeIQx), 2-amino-3,7,8-trimethylimidazo[4,5-f] quinoxaline (7,8-DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Dietary intake data were obtained using a food-frequency questionnaire when interviewing 600 Malaysian respondents. The level of total heterocyclic amines in food samples studies ranged from not detected to 38.7 ng g^?1. The average daily intake level of heterocyclic amine was 553.7 ng per capita day^?1. The intake of PhIP was the highest, followed by MeIQx and MeIQ. The results reveal that fried and grilled chicken were the major dietary source of heterocyclic amines in Malaysia. However, the heterocyclic amine intake by the Malaysian population was lower than those reported from other regions.     

Antioxidant spices reduce the formation of heterocyclic amines in fried meat

 Heterocyclic aromatic amines (HAs) are mutagenic compounds that are formed during heating of meat and fish. These substances are reaction products of creatine with amino acids and carbohydrates. It is recommended that exposure to these probable human carcinogens should be minimised. Five heterocyclic aromatic amines which occur in beef were investigated: 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethyl-imidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethyl-imidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethyl-imidazo[4,5-f]quinoxaline (4,8-DiMeIQx), and 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP). Clean-up was done by acid-base partition followed by SPE using blue cotton. HPLC analysis was carried out by using electrochemical detection for IQ- and IQx-type compounds and fluorescence detection for PhIP. The concentrations of the aromatic amines were as follows: IQ, 10.2 μg/kg; MeIQ, 2.46 μg/kg; MeIQx, 13.2 μg/kg; 4,8-DiMeIQx, 2.26 μg/kg; and PhIP, 5.48 μg/kg. The application of spices (rosemary, thyme sage, garlic, brine) reduced the content of the HAs below 60% of the amount found in the control. Received: 23 April 1998     

Effects of varying degrees of doneness on the formation of Heterocyclic Aromatic Amines in chicken and beef satay

The study was carried out to determine the effect of cooking method on Heterocyclic Aromatic Amines (HAs) concentration in grilled chicken and beef (satay). Six common HAs were investigated: 2-amino-3-methylimidazo[4,5-f]quinolone (IQ), 2amino 3,4dimethylimidazo [4,5f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8 trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-3,7,8trimethylimidazo [4,5-f]quinoxaline (7,8-DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Chicken and beef satay samples were grilled to medium and well done level of doneness. Charcoal grilled (treatment A), microwave pre-treatment prior to grilling (treatment B), and microwave-deep fried (treatment C) were applied to beef and chicken satay samples. The satay samples which were microwaved prior to grilling (B) showed significantly (p < 0.05) lower HAs concentration as compared to those charcoal grilled (A). Both medium and well done cooked beef and chicken satay samples that were microwaved and deep fried (C) as an alternative method to grilling were proven to produce significantly lesser HAs as compared to charcoal-grilled (A) and microwaved prior to grilling (B).     

Effects of cooking methods on the formation of heterocyclic aromatic amines of two different species trout

Heterocyclic aromatic amines (HAAs) are sometimes formed in meats and fish cooked at high temperatures. In the present study, the effects of cooking methods by deep-fat frying, pan-frying, grilling and barbecuing on the formation of HAAs of fillets of rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta fario) were investigated. Barbecued brown trout (1 g) was estimated to contain 0.12 ng of IQ (2-amino-3-methylimidazo[4,5-f]quinoline), 0.02 ng 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline). Grilled rainbow trout (1 g) was estimated to contain 0.02 ng 4,8-DiMeIQx. MeIQ (2-amino-3,4-dimethylimidazo[4,5-f]quinoline), MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) were not detectable in all cooked fish.     

Response surface optimization of effects of some processing variables on carcinogenic/mutagenic heterocyclic aromatic amine (HAA) content in cooked patties

A five-factor Central Composite Orthogonal Design was adopted to study simultaneous effects of some processing variables such as NaCl (0-2%), fat (10-30%), ascorbic acid (0-600 ppm), cooking temperature (150-230°C) and cooking time (5-15 min) on physicochemical properties and heterocyclic aromatic amine (HAA) contents of cooked beef patties. The HAAs analyzed were 2-amino-3-methylimidazo[4,5-f]-quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]-quinoxaline (MeIQx), 2-amino-3,4-dimethylimidazo[4,5-f]-quinoline (MeIQ), 2-amino-3,4,8-trimethylimidazo[4,5-f]-quinoxaline (4,8-DiMeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), as quantified by high-performance liquid chromatography with photo-diode array detection (HPLC-UV/DAD). It was found that ascorbic acid decreased; however, fat, cooking temperature and time levels increased the contents of IQ, MeIQx, MeIQ and PhIP. In addition, estimated ridge analysis was conducted to find values of the processing variables that maximize and minimize the five HAA contents, revealing that the results obtained would be useful for meat industry aiming to decrease HAA content in cooked meat products.     

抗氧化剂对油炸肉制品品质及杂环胺形成的影响

系统全面分析GB 2760—2014《食品添加剂使用标准》允许添加至油炸肉制品使用的8 种抗氧化剂对3 种炸肉饼食用品质及杂环胺（heterocyclic amines,HAs）形成的影响。结果发现,不同抗氧化剂对不同种类肉制品的品质影响不同。竹叶提取物（extract of bamboo leaves,BL）、植酸钠（phytic acid,PA）、鼠尾草酸（carnosic acid,CA）、迷迭香酸（rosmarinci acid,RA）及茶多酚（tea polyphenols,TP）具有良好的保持3 种肉饼油炸过程中水分含量的能力,其能够降低油炸损失率,改善嫩度和质构特性等。不同抗氧化剂对炸肉饼中不同种类HAs形成的抑制活性有一定差异。炸鸡肉饼中,山梨酸钾（potassium sorbate,PS）对2-氨基-1-甲基-6-苯基咪唑并[4,5-b]吡啶（2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine,PhIP）的抑制率相对最高（48%）,CA表现出对2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉（2-amino-3,8-dimethyl-imidazo[4,5-f]-quinoxaline,8-MeIQx）相对最高的抑制率（56%）,PA、CA和PS显著降低炸鸡肉饼中总HAs含量（P＜0.05）;对于炸牛肉饼,CA对PhIP的抑制效果相对最佳,并且其与BL对8-MeIQx的抑制效果显著优于其他6?种抗氧化剂（P＜0.05）,CA、BL和PS显著抑制炸牛肉饼中总HAs的形成（P＜0.05）;炸猪肉饼中,BL对PhIP表现出相对最强的抑制活性（抑制率为64%）,8?种抗氧化剂均能显著抑制8-MeIQx和2-氨基-3,4,8-三甲基咪唑并[4,5-f]喹喔啉的形成（P＜0.05）,并且BL对总HAs表现出相对最佳的抑制效果,抑制率为49%。总体而言,BL、CA、PA、TP、RA及PS对油炸肉制品中HAs的形成表现出相对更优的抑制活性。     

温和条件下模型体系中烧烤风味及杂环胺形成测定

以美拉德模型体系葡萄糖-肌酸酐-氨基酸（丙氨酸、苏氨酸、甘氨酸）为研究对象,探索3 个体系在130 ℃条件下反应3 h后风味物质及杂环胺的形成。采用固相微萃取-气相色谱-质谱联用方法检测表明,3 种模型均产生烧烤风味物质,主要为烷基吡嗪类。高效液相色谱分析表明,丙氨酸模型（Ⅰ）和甘氨酸模型（Ⅲ）均检测到2-氨基-3,4-二甲基咪唑并[4,5-f]喹啉、2-氨基-3,4,8-三甲基咪唑并[4,5-f]喹喔啉和2-氨基-3,7,8-三甲基咪唑并[4,5-f]喹喔啉3 种杂环胺,苏氨酸模型（Ⅱ）检测到了2-氨基-3,4-二甲基咪唑并[4,5-f]喹啉和2-氨基-3,4,8-三甲基咪唑并[4,5-f]喹喔啉2 种杂环胺;3 种模型体系均未检测到2-氨基-3-甲基咪唑并[4,5-f]喹啉和2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉。130 ℃温和条件下,1.5 h内各模型体系中杂环胺的生成量很少,1.5 h后杂环胺总量随着加热时间的延长逐渐增多,3 h时模型Ⅰ、Ⅱ、Ⅲ中杂环胺总量分别为（375.50±15.80）、（414.00±18.40）、（363.50±12.20） ng/mL。本研究为肉制品加工尤其是烤肉制品加工如何控制加工条件,从而实现美拉德反应定向控制、减少杂环胺的产生提供一定参考。     

Tandem solid phase extraction coupled to LC–ESI–MS/MS for the accurate simultaneous determination of five heterocyclic aromatic amines in processed meat products

Carcinogenic heterocyclic aromatic amines are difficult to measure since only trace levels are present in processed meat products. In this study, typical heterocyclic aromatic amines, including 2-amino-3-methylimidazo [4,5-f] quinoline (IQ), 2-amino-3,4-dimethylimidazo [4,5-f] quinoline (MeIQ), 2-amino-3,8-dimethyli-midazo [4,5-f] quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimi-dazo [4,5-f] quinoxaline (4,8-DiMeIQx), 2-amino-1-methyl-6-ph-enylimidazo [4,5-b]pyridine (PhIP), were studied to develop a sensitive and accurate method for their rapid quantification in animal-derived products, with 2-Amino-3,4,7,8-dimethylimidazo [4,5-f] quinoxalline (TriMeIQx) as an internal standard. Liquid chromatography–electrospray-tandem mass spectrometry conditions were analyzed to enhance detection sensitivity. Diatomaceous earth was employed to extract heterocyclic aromatic amines from meat samples, and the analytes were purified and enriched using tandem solid phase extraction, with siliprep propylsulfonic acid coupled to a C₁₈ cartridge. A number of parameters, including pH, eluent and volume, were carefully optimized to improve the extraction and purification efficiency. Under the optimal experimental conditions, the limits of detection for each analyte within the meat matrix were 0.5 pg (injected). The established method was applied to evaluate commercial meat products. At three spiked levels of 0.2, 1 and 4 μg kg⁻¹, the recoveries and relative standard deviations were measured as 76.4–122.2 and 0.9–23.4%, respectively, suggesting the developed method is promising for the accurate quantification of heterocyclic aromatic amines at trace levels in processed meats.     

Effect of enhancement on the formation of heterocyclic amines in cooked pork loins: Preliminary studies

Heterocyclic amines (HCAs) which are produced in meats cooked at high temperature a risk factor for certain human cancers. This study evaluated the effect of enhancement on HCA formation in cooked pork loins. Three samples of pork loin were prepared including non-injected loin, 12% water-injected loin, and 12% salt/phosphate injected loin. The HCAs were identified in all samples: PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine), MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline), and DiMeIQx (2-amino-3,4,8-trimethylimidazo [4,5-f]quinoxaline). Injection of salt/phosphate significantly reduced the level of PhIP by 42.7%, MeIQx by 79.0%, and DiMeIQx by 75.0%. Enhancement with water alone did not reduce HCA formation.     

Occurrence of heterocyclic amines in cooked meat products

Heterocyclic amines (HCAs), potent mutagens and a risk factor for human cancers, are produced in meats cooked at high temperature. The aim of this study was to determine the HCA content in cooked meat products (beef, chicken, pork, fish) prepared by various cooking methods (pan frying, oven broiling, and oven baking at 170 to 230 °C) that are preferred by U.S. meat consumers. The primary HCAs in these samples were PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine) (1.49-10.89 ng/g), MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline) (not detected-4.0 ng/g), and DiMeIQx (2-amino-3,4,8-trimethyl-imidazo [4,5-f]quinoxaline) (not detected-3.57 ng/g). Type and content of HCAs in cooked meat samples were highly dependent on cooking conditions. The total HCA content in well-done meat was 3.5 times higher than that of medium-rare meat. Fried pork (13.91 ng/g) had higher levels of total HCAs than fried beef (8.92 ng/g) and fried chicken (7.00 ng/g). Among the samples, fried bacon contained the highest total HCA content (17.59 ng/g).     

葡萄籽提取物对烤羊肉中杂环胺形成的影响

将0.05%VE,0.1%与0.5%葡萄籽提取物,0.1%与0.5%槲皮素分别添加于羊肉表面,在200℃下煎烤10 min,利用固相萃取-配备二极管阵列检测器和荧光检测器的高效液相色谱分析烤羊肉中15种杂环胺的形成量,以探讨天然提取物对烤羊肉中杂环胺形成量的影响。结果表明:烤羊肉中共检测出10种杂环胺,其中极性杂环胺4种,非极性杂环胺6种,总量达51.68 ng/g。在极性杂环胺中2-氨基-1-甲基-6-苯基-咪唑并[4,5-b]吡啶(PhIP)的形成量较高,达10.50 ng/g;非极性杂环胺中9H-吡啶并[3,4-b]吲哚(Norharman)与1-甲基-9H-吡啶并[3,4-b]吲哚(Harman)的形成量较高,分别达19.66 ng/g与12.23 ng/g。烤羊肉中添加天然抗氧化剂只对极性杂环胺有抑制作用,其中添加0.5%葡萄籽提取物可以显著抑制2-氨基-3甲基咪唑并[4,5-f]喹啉(IQ),2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉(MeIQx),2-氨基-3,4,8-三甲基咪唑并[4,5-f]喹喔啉(4,8-DiMeIQx)与PhIP 4种极性杂环胺的形成(P<0.05),其生成量分别减少36.65%,67.73%,35.63%与30%。天然抗氧化剂对烤羊肉中非极性杂环胺的抑制作用不明显。     

Chemical analysis of heterocyclic aromatic amines: the results of two European projects compared

 This report describes two studies which compared the results of the analyses of four heterocyclic aromatic amines (HAAs): 2-amino-3-methylinidazo[4,5-f]quinoline (IQ); 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx); 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), first as pure methanolic solutions and, in a second step, in a food matrice (beef extract) spiked with known amounts of these four HAAs. Details are given for the preparation of the methanolic solutions of the four HAAs and for the homogeneity and stability studies. The results of different statistical treatments revealed no significant heterogeneity within or between ampoules. The results of the stability studies clearly indicated that, except for PhIP, no effect of storage period (up to 6 months) or storage temperature (up to 25  °C), existed for the five HAAs methanolic solutions. Each of the eight European participating laboratories, which has leading experience in the analysis of HAAs, received sealed ampoules containing the pure reference solutions of the four HAAs together with a mixture of unknown identity and concentration. For the analysis of the unknwon sample, participants followed, a common work programme, but used different columns, solvent gradients and detection systems (UV, fluorescence, mass spectrometry and electrochemical detection. The analysis of the results of this first comparison revealed a good correlation between the results provided by the participants and high precision regarding the target values, independent of the experimental conditions used. For the second comparison, a common batch of commercial beef extract was prepared and spiked with known amounts of the four HAAs. The long-term stability study at –18  °C, 4  °C, 25  °C, 40  °C and 60  °C revealed high stability of these four HAAs, during up to 6 months of storage. At 40  °C and 60  °C, however, a significant loss was observed, in particular for PhIP. On the other hand, the 1-year stability study revealed that the HAAs content did not change when beef extract was stored at –18  °C. Details of these homogeneity and stability studies are provided. The sealed ampoules containing beef extract, together with the reference methanolic solutions were sent to the participants in refrigerated container. The eight European laboratories, which participated in the first comparision, adopted the work programme of this exercise. They generally followed a previously agreed upon solid-phase extraction procedure, very similar to that described by Gross [8], with analysis by HPLC. Column conditions, solvent elution and detection by UV, fluorescence, mass spectrometry and electrochemical detection varied between laboratories. The objectives of this second phase of the project were to compare and improve usual routine laboratory methods for the determination of IQ, MeIQx, 4,8-DiMeIQx and PhIP in the range of 1–30 ng/g, in a commercial beef extract. The comparision of the results revealed, however, large variations, not only beween but also within laboratories. Major difficulties were encountered by the participants, mainly for the determination of PhIP. Acceptable recovery levels were agreed between participants and different sources of variability in the extraction procedures were identified. In conclusion, whereas the analytical determination of HAAs in beef extract appeared to be satisfactory, the procedures of isolation and purification require further improvement. Received: 23 April 1998     

Chemical analysis of heterocyclic aromatic amines: the results of two European projects compared

 This report describes two studies which compared the results of the analyses of four heterocyclic aromatic amines (HAAs): 2-amino-3-methylinidazo[4,5-f]quinoline (IQ); 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx); 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), first as pure methanolic solutions and, in a second step, in a food matrice (beef extract) spiked with known amounts of these four HAAs. Details are given for the preparation of the methanolic solutions of the four HAAs and for the homogeneity and stability studies. The results of different statistical treatments revealed no significant heterogeneity within or between ampoules. The results of the stability studies clearly indicated that, except for PhIP, no effect of storage period (up to 6 months) or storage temperature (up to 25  °C), existed for the five HAAs methanolic solutions. Each of the eight European participating laboratories, which has leading experience in the analysis of HAAs, received sealed ampoules containing the pure reference solutions of the four HAAs together with a mixture of unknown identity and concentration. For the analysis of the unknwon sample, participants followed, a common work programme, but used different columns, solvent gradients and detection systems (UV, fluorescence, mass spectrometry and electrochemical detection. The analysis of the results of this first comparison revealed a good correlation between the results provided by the participants and high precision regarding the target values, independent of the experimental conditions used. For the second comparison, a common batch of commercial beef extract was prepared and spiked with known amounts of the four HAAs. The long-term stability study at –18  °C, 4  °C, 25  °C, 40  °C and 60  °C revealed high stability of these four HAAs, during up to 6 months of storage. At 40  °C and 60  °C, however, a significant loss was observed, in particular for PhIP. On the other hand, the 1-year stability study revealed that the HAAs content did not change when beef extract was stored at –18  °C. Details of these homogeneity and stability studies are provided. The sealed ampoules containing beef extract, together with the reference methanolic solutions were sent to the participants in refrigerated container. The eight European laboratories, which participated in the first comparision, adopted the work programme of this exercise. They generally followed a previously agreed upon solid-phase extraction procedure, very similar to that described by Gross [8], with analysis by HPLC. Column conditions, solvent elution and detection by UV, fluorescence, mass spectrometry and electrochemical detection varied between laboratories. The objectives of this second phase of the project were to compare and improve usual routine laboratory methods for the determination of IQ, MeIQx, 4,8-DiMeIQx and PhIP in the range of 1–30 ng/g, in a commercial beef extract. The comparision of the results revealed, however, large variations, not only beween but also within laboratories. Major difficulties were encountered by the participants, mainly for the determination of PhIP. Acceptable recovery levels were agreed between participants and different sources of variability in the extraction procedures were identified. In conclusion, whereas the analytical determination of HAAs in beef extract appeared to be satisfactory, the procedures of isolation and purification require further improvement. Received: 23 April 1998     

Analysis of heterocyclic amines and β-carbolines by liquid chromatography–mass spectrometry in cooked meats commonly consumed in Korea

Heterocyclic amines (HAs), which form in meats during heating and cooking, are recognized as mutagenic and carcinogenic compounds. In this study, 13 HAs and 2 β-carbolines (BCs) were analyzed in cooked Korean meat products, including griddled bacon, griddled pork loin, boiled pork loin, boiled chicken meat, chicken meat stock, chicken breast for salad and chicken patty. The samples were either cooked in the laboratory or purchased from local fast-food restaurants. The HAs and BCs in the samples were separated using solid-phase extraction and were analyzed by high performance liquid chromatography–mass spectrometry (HPLC–MS). The most frequently detected HAs and BCs in the cooked meats were harman (1-methyl-9H pyrido[4,3-b]indole; 990.9 ng g^?1), norharman (9H-pyrido[4,3-b]indole; 412.7 ng g^?1) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine; 258.2 ng g^?1). The griddled pork loin and bacon contained higher levels of norharman, harman and PhIP than the other cooked meats. PhIP, which is classified as a Group 2B carcinogen by the International Agency for Research on Cancer, had levels of 258.2 and 168.2 ng g^?1 in the griddled pork loin and griddled bacon, respectively. The griddled bacon was the only sample containing TriMeIQx (2-amino-3,4,7,8-tetramethylimidazo[4,5-f]quinoxaline; 79.9 ng g^?1). IQ (2-amino-3-methyl imidazo[4,5-f]quinoline), 7,8-DiMeIQx (2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline), 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline) and AαC (2-amino-9H-pyrido[2,3-b]indole) were detected at trace levels in all samples.     

Determination of Heterocyclic Aromatic Amines in Cooked Commercial Frozen Meat Products by Ultrafast Liquid Chromatography

This paper describes a method for the determination of nine heterocyclic aromatic amines (HCAs) in commercial frozen meat products, which were sold in Turkey by ultrafast liquid chromatography (UFLC) with ultraviolet visible detection. HCAs are separated on a Shim-pack XR-ODS (7.5?×?3 mm, 2.2 μm). Varying levels of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) (up to 1.95 ng/g), 2-amino-3-methylimidazo[4,5-f]quinoxaline (IQx) (up to 4.17 ng/g), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) (up to 0.69 ng/g), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (up to 0.83 ng/g), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) (up to 0.22 ng/g), 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx) (up to 0.94 ng/g), 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP) (up to 4.58 ng/g), 2-amino-9H-pyrido[2,3-b]indole (AαC) (up to 0.57 ng/g), and 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAαC) (up to 3.51 ng/g) were detected in these commercial frozen meat products of Turkey. The data obtained show clearly that HCAs could be isolated in a very short time (5 min) by using UFLC.     

前体物含量对杂环胺形成的影响

将牛、猪、羊、鸡、鸭和鹅肉分别在200℃下煎烤10 min,分析其原料肉中前体物的含量与加工肉制品中杂环胺的形成量,以探讨不同动物原料肉中杂环胺的形成量及原料肉中前体物的含量对杂环胺形成的影响。结果表明,6种原料肉中前体物含量差异较大,肌酸与葡萄糖的摩尔浓度比在0.89～9.84之间。加工肉制品中共检测出10种杂环胺,其中9H-吡啶并[3,4-b]吲哚(Norharman)与1-甲基-9H-吡啶并[3,4-b]吲哚(Harman)在加工肉品中含量最高,分别在10.90～24.16 ng/g与4.64～14.04 ng/g之间。而2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉(MeIQx)在牛肉中形成量较高,达3.55 ng/g,2-氨基-1-甲基-6-苯基-咪唑并[4,5-b]吡啶(PhIP)在禽肉中易于产生,其中鸡肉中含量最高,达15.26 ng/g。PhIP与肌酸和葡萄糖的摩尔浓度比存在相关性(P<0.05),随着葡萄糖浓度的增高,PhIP的形成量减少。     

Preconcentration and Simultaneous Determination of Heterocyclic Aromatic Amines in Grilled Pork Samples by Ion-Pair-Based Surfactant-Assisted Dispersive Liquid-Liquid Microextraction and High-Performance Liquid Chromatography

An effective ion-pair-based surfactant-assisted dispersive liquid-liquid microextraction combined with high-performance liquid chromatography (HPLC) has been evaluated for the extraction and preconcentration of four heterocyclic aromatic amines (i.e., 2-amino-3,4-dimethyl-3H-imidazo[4,5-f]quinoline (MeIQ); 2-amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (4,8-DiMeIQx); 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP); and 1-methyl-9H-pyrido[3,4-B]indole (Harmane)). In the extraction method, sodium dodecyl sulfate (SDS) was used as both ion-pairing and disperser agent and 1-octanol was selected as extraction solvent. The effects of various parameters on the extraction efficiency such as kind and concentration of surfactant, kind and volume of extraction, salt addition, vortex extraction, and centrifugation time were investigated. Under the selected condition, the method provided high enrichment factor in the ranged of 124–145. Good linearity was 0.01–1000 μg kg^?1 with the correlation coefficient (R ²)?>?0.999. The limit of detection was 0.01 μg kg^?1 for all compounds. The matrix match calibration was used for quantitation of the target analytes in grilled pork samples. The proposed method was successfully applied to analysis of heterocyclic aromatic amines in grilled pork samples where good recoveries were obtained in the range of 90 and 106 %.     

FORMATION OF HETEROCYCLIC AMINES IN MEAT EMULSION EXTENDED WITH SOY PROTEIN

Formation of heterocyclic amines (HAs) during heating of meat emulsions at selected temperatures was studied to determine the influence of soy protein and fat contents on yields of HAs. Meat emulsion with two different fat contents, 6% (low) and 19% (high), and with two soy protein contents, 0% (none) and 10%, were used in the study. The emulsions were heated at temperatures of 180 and 200C for times varying from 0 to 40 min. HAs namely IQx (2-amino-3-methylimidazo[4,5-f]quinoxaline), MelQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline), and PhIP (2-amino-1-methy-6-phenylimidazo[4,5-b]pyridine) were identified and quantified in the meat emulsions. Concentrations of IQx were from 0 to 8.26 ng/g of emulsion; MeIQx concentrations were from 0 to 14.73 ng/g and PhIP concentrations were from 0 to 2.48 ng/g. Yields of the HAs depended on temperature, time, soy protein and fat contents. Formation of the HAs in the meat emulsions after an initial lag period followed first order kinetics. Increasing soy protein content decreased the maximum concentrations of IQx and MeIQx formed at the different heating condition.     

Heterocyclic aromatic amines in cooked hamburgers and chicken obtained from local fast food outlets in the Ottawa region

Heterocyclic aromatic amines (HAAs) are formed in protein-rich foods during high temperature cooking such as frying and grilling. Since most HAAs are potent mutagens and almost all are carcinogenic to laboratory animals, their formation in cooked foods is a health concern. In the present study, 31 cooked hamburgers and six chicken preparations were obtained from various fast food outlets in the Ottawa area and analyzed for HAAs. In the developed procedure, ground-up samples were extracted under both acidic and alkaline conditions, cleaned on SPE cartridges, and the concentrations of various HAAs determined using electrospray ionization LC/MS/MS. Deuterium-labelled internal standards of the three most commonly found HAAs (IQ, MeIQx, and PhIP) in such foods were used for quantitation and recovery correction. Varying levels of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (0.2–6 μg/kg), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) (0.1–3.5 μg/kg), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (0.3–6.9 μg/kg), and 7,8-dimethyl-IQx (2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline) (0.1–2.9 μg/kg) were detected in most hamburgers, whereas our limited data on the chicken samples (wings, drumsticks, and nuggets) indicated the presence of mainly PhIP (0.1–2.1 μg/kg) and MeIQx (0.1–1.8 μg/kg). Traces of 4,7,8-trimethyl-IQx (<0.1 μg/kg), 3-amino-1,4-dimethyl-5H-pyrido[3,4-b]indole (Trp-P-1) (<0.1–0.3 μg/kg), and 3-amino-1-methyl-5H-pyrido[3,4-b]indole (Trp-P-2) (<0.1–0.8 μg/kg) were also detected in some samples of hamburgers but not in any of the chicken analyzed thus far. Since hamburger is a popular meal among Canadians, regular consumption of such items may contribute substantially to one's dietary intake of HAAs.