Air-Agitated Cloud-Point Extraction Coupled with High-Performance Liquid Chromatography for Determination of Heterocyclic Aromatic Amines in Smoked Sausages

An air-agitated cloud-point extraction procedure (AACPE), which is a new generation of cloud-point extraction procedure, has been investigated for extraction and preconcentration of four heterocyclic 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)) prior to high-performance liquid chromatography (HPLC). In order to enhance the extraction efficiency, the mixture of the aqueous sample solution and extraction solvent (Triton X-114) was repeatedly aspirated and dispensed using a syringe. Various parameters affecting the extraction efficiency of the AACPE procedure, including type and amount of salt, concentration of Triton X-114, extraction time (or number of air agitations), and centrifugation time, were investigated. No temperature controller was necessary. Under the optimum extraction condition, the linearity was achieved between 0.005 and 1.00 mg kg^?1 with the correlation coefficient (R ²) > 0.999. The low limit of detections (LODs) ranged from 0.001 to 0.003 mg kg^?1 with high enrichment factor (EF) more than 80. Matrix-matched calibration has been used for analysis of the target analytes in real samples. The applicability of the developed procedure was successfully evaluated by the determination of the heterocyclic amines in smoked sausage samples.     

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.     

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.     

Formation and mitigation of heterocyclic aromatic amines in fried pork

Heterocyclic aromatic amines (HAAs) are potent mutagens and carcinogens generated during the heat processing of meat. HAAs, which are abundant in processed meat products, include 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). The content of these three HAAs in fried pork was determined by LC-MS/MS. The effects of frying time and temperature, sample shape, and addition of antioxidants on the generation of HAAs were investigated. The results show that HAAs were produced during frying, and their levels increased with increasing frying time and temperature. Pork patties had the highest concentration of HAAs compared with pork meatballs and pork strips. The addition of antioxidant of bamboo leaves (AOB), liquorice extract, tea polyphenol, phytic acid and sodium iso-ascorbate to pork before frying had an inhibitory effect on HAA generation, with AOB being the most effective antioxidant. Inhibition levels of nearly 69.73% for MeIQx, 53.59% for 4,8-DiMeIQx and 77.07% for PhIP in fried pork were achieved when the concentrations of AOB added were 0.02, 0.01 and 0.10 g kg^?1, respectively.     

Analysis of heterocyclic aromatic amines by high resolution gas chromatography-mass spectrometry: a suitable technique for the routine control of food and process flavours

 Ten heterocyclic aromatic amines (HAA; [2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (1); 2-amino-3,4-dimethyl-3H-imidazo[4,5-f]quinoline (2); 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (3); 2-amino-3,8-dimethyl-3H-imidazo[4,5-f]quinoline (4); 2-amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoline (5); 2-amino-3,7,8-trimethyl-3H-imidazo[4,5-f]quinoline (6); 2amino-3,4,7,8-tetramethyl-3H-imidazo[4,5-f]quinoline (7); 2-amino-1-methyl-6-phenyl-imidazo[4,5-f]quinoline (8); 2-amino-6-methyldipyrido[1,2-α : 3′,2′-d]imidazole (9); 2-aminodipyrido[1,2-α : 3′,2′-d]imidazole (10)]) were analysed in commercially available meat products and process flavours. After sample preparation by Extrelut treatment, subsequent solid phase extraction applying propylsulphonic and C₁₈ silica cartridges, as well as derivatization with 3,5-bis-trifluoromethylbenzyl bromide, HRGC-electron-impact-ionization-MS (HRGC-EIMS) analysis in the selected ion monitoring mode was performed. Isotope dilution analysis with 2amino-8-methyl-3-(trideuteromethyl)-3H-imidazo[4,5- f]quinoxaline and 2-amino-1-(trideuteromethyl)-6-phenyl-imidazo[4,5-b]pyridine was used to quantify 4 and 8; for 1–3, 5–7, 9 and 10, standard addition was employed as the determination method. The detection limit of 1 ng/g evaluated for 3–6 and 9 was sufficient for routine analysis, i.e. to obtain an initial insight into the grade of a potential HAA contamination of food or process flavours. To obtain more detailed information, the previously developed, more sensitive technique of HPLC-electrospray-tandem-MS (HPLC-ESI-MS/MS) has to be used, as shown by the comparison of the data obtained by HRGC-MS and HPLC-ESI-MS/MS analyses. Received: 4 March 1999     

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).     

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     

Development of a New Extraction Method for Heterocyclic Aromatic Amines Determination in Cooked Meatballs

Heterocyclic aromatic amines (HCAs) are mutagenic and carcinogenic compounds that are produced in meats cooked at high temperature. In this study, 2-amino-3-methylimidazo[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), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 9H-pyrido[3,4-b]indole (norharman), and 1-methyl-9H-pyrido[3,4-b]indole (harman) were studied. A new extraction method was developed for the determination of heterocyclic amines with high-performance liquid chromatography (HPLC). Linearity for each HCA was observed with a high regression coefficient (r?=?0.9999, P?<?0.01 for IQ; r?=?0.9990, P?<?0.01 for MeIQx; r?=?0.9989, P?<?0.01 for 4,8-DiMeIQx; r?=?0.9934, P?<?0.05 for PhIP; r?=?1.000, P?<?0.01 for norharman; r?=?0.9991, P?<?0.01 for harman). Limits of detection for various HCAs were found between 0.04 and 1.40 ng/g. Limits of quantification were found in the range of 0.13–4.40 ng/g. Recovery rates varied from 68.9 % to 87.8 %. This method was compared with two different common HCA extraction methods in literature. The optimized new extraction method and the other two methods were used for the determination of HCAs in ten different cooked meatball samples. Sample extraction procedures of HCAs were investigated in more detail, and a rapid, accurate, precise, and reliable extraction method was developed.     

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     

Content,causes and analysis of heterocyclic amines in Chinese traditional braised chicken

ABSTRACT

Braised chicken is a popular traditional chicken product in China with a special and complicated culinary method. However, there has been little research focused on the food safety problems caused by hazardous compounds in braised chicken. In this study, the contents of heterocyclic amines (HCAs) in representative braised chicken samples were determined. Total HCAs in braised chicken were relatively high (6.20–27.7 ng g^?1), and aminoimidazoazaarenes (AIAs) took a large proportion (54.0–86.4%). 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ) was found in all samples with a high level (2.72–13.5 ng g^?1), whilst 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was low (0.14–0.41 ng g^?1). 9H-pyrido[3,4-b]indole (Norharman) and 1-methyl-9H-pyrido[3,4-b]indole (Harman) were main components in aminocarbolines (ACs). So the potential safety risk in braised chicken caused by high HCAs content should be paid attention. Principal component analysis (PCA) was used to analyse and visualise the differences of HCAs levels among braised chicken samples. The result indicated that the differences among these samples were significant, but there were no obvious similarities between samples produced in the same regions. Moreover, there were rare significant positive correlations between chemical components (including moisture, fat, protein, creatine and free amino acids) and hazardous compounds. Considering PCA and correlation analysis results, these parameters may play a major role in the HCAs levels in Chinese traditional braised chicken.     

Inhibitory effect of mixture herbs/spices on formation of heterocyclic amines and mutagenic activity of grilled beef

ABSTRACT

Natural antioxidants in spices and herbs have attracted considerable attention as potential inhibitors against the formation of mutagenic heterocyclic amines (HCAs) in heat-processed meat. In this study, the inhibitory activity of four spices/herbs and their mixtures on HCAs formation in grilled beef were examined. A simplex centroid mixture design with four components comprising turmeric, curry leaf, torch ginger and lemon grass in 19 different proportions were applied on beef samples before grilling at 240 ºC for 10 min. The HCAs were extracted from the samples using solid phase extraction (SPE) method and analysed using Liquid chromatography mass spectrometry LC-MS/MS. All spices/herbs in single or mixture forms were found to reduce total HCA concentrations in marinated grilled beef ranging from 21.2% for beef marinated with curry leaf to 94.7% for the combination of turmeric and lemon grass (50:50 w/w). At the optimum marinade formula (turmeric: lemon grass 52.4%: 47.6%), concentration of 2-amino-3-methylimidazo[4,5-f]quinolone (IQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), Harman, Norharman and AαC were 2.2, 1.4, 0.5, 2.8 and 1.2 ng/g, respectively. The results of the mutagenic activity demonstrated that this optimised marinade formula significantly (p < 0.05) diminished mutagenicity of marinated grilled beef in bacterial Ames test.     

植物多酚抑制热加工肉制品中杂环胺形成机制研究进展

杂环胺（heterocyclic amines,HAs）是肉制品热加工过程中产生的一类具有极强致畸致癌活性的有毒化合物,其中2-氨基-3-甲基咪唑并[4,5-f]喹啉（2-amino-3-methyl-imidazo[4,5-f]-quinoline,IQ）和2-氨基-3,4-二甲基咪唑并[4,5-f]喹啉（2-amino-3,4-dimethyl-imidazo[4,5-f]-quinoline,MeIQ）,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）,1-甲基-9H-吡啶并[3,4-b]吲哚（1-methyl-9Hpyrido[3,4-b]indole,Harman）和9H-吡啶并[3,4-b]吲哚（9H-pyrido[3,4-b]indole,Norharman）3类HAs在热加工肉制品中较为常见且分布广泛。本文即围绕上述3类HAs,简要分析其形成的途径及机制,并详细阐述外源添加植物多酚抑制HAs形成的作用机制,最后依据现有研究归纳总结出多酚化合物抑制HAs与其化...     

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.     

Formation of heterocyclic amines during cooking of duck meat

Heterocyclic amines (HAs) are an important class of food mutagens and carcinogens produced in meat cooked at high temperature. In the present study, the effects of various cooking methods: boiling, microwave cooking, charcoal-grilling, roasting, deep-frying and pan-frying on the formation of HAs in duck breast were studied. The various HAs formed during cooking were isolated by solid-phase extraction and analysed by HPLC. Results showed that both the varieties and contents of HAs and the cooking loss of duck breast increase along with increasing cooking temperature and time. Pan-fried duck breasts contained the highest amount of total HAs, followed by charcoal-grilling, deep-frying, roasting, microwave cooking and boiling. 9H-pyrido[3,4-b]indole (norharman) and 1-methyl-9H-pyrido[3,4-b]indole (harman) were detected in all of the cooked duck meat, with levels in the range of 0.1–33?ng?g^?1. 2-Amino-1-methyl-6-phenylimidazo[4,5-f]pyridine (PhIP) was formed easily in duck meat cooked by pan-frying and charcoal-grilling in the range of 0.9–17.8?ng?g^?1. 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ) was identified in duck meat cooked by charcoal-grilling and pan-frying, in the range of 0.4–4.2?ng?g^?1. 2-Amino-3,8-dimethyl-imidazo[4,5-f]quinoxaline (MeIQx) was detected in amounts below 4.5?ng?g^?1 in duck meat cooked by charcoal-grilling, roasting, deep-frying and pan-frying. The other HAs were detected in amounts below 10?ng?g^?1. Colour development increased with cooking temperature, but no correlation with HAs’ content was observed.     

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.     

Comparative mutagenicity studies on fried minced beef,grilled sausage and grilled hamburgers

The mutagenicity of the basic fractions of fried beef patties, grilled hamburgers and grilled sausages was determined in the Ames test using activation systems (S9-mix) derived from untreated and Aroclor-pretreated rats and hamsters, and from rats pretreated with 3-methylcholanthrene or phenobarbitone. In order to indicate whether the mutagenic activity was due to the presence of thermally generated amino imidazo aza-arenes of the type previously identified in heated meat products (i.e. 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo-[4,5-f]quinoline (MeIQ) and 2-amino-3,8-dimethylimidazo[4,5-f]quin-oxaline), these compounds were assayed under the same conditions. The mutagenicity of the basic fractions of the cooked foods and of the three aza-arenes varied with the activation system used. The activation patterns of the basic fractions from fried beef and grilled sausages resembled that of IQ, whereas that of grilled hamburgers was more similar to that of MeIQ. Interestingly the total mutagenic activity of fried beef patties was greater than that of grilled hamburgers.     

Determination of Polycyclic Aromatic Hydrocarbons (PAH4) in the Traditional Lebanese Grilled Chicken: Implementation of New,Rapid and Economic Analysis Method

Polycyclic aromatic hydrocarbons (PAH4) (benzo[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene) are evaluated in a traditional and widely consumed staple in Lebanon “Lebanese Grilled Chicken.” Forty samples with different local additives grilled by charcoal were purchased from different restaurants located in different regions in Lebanon. For this purpose, a simple and a reliable analytical method based on sonication technique and gas chromatography coupled to mass spectrometer (GC-MS) has been developed and validated. Several parameters affecting the extraction efficiency, such as the nature and the volume of the extract solvent, as well as other factors were investigated and optimized. The developed method is environmentally and economically friendly with a minimized consuming time, consisting of a single sonication step for 15 min using 12 mL of non-carcinogenic solvent acetonitrile (ACN) and without any further concentration prior to analysis. Following extraction, the cleanup step was based on freezing and d-SPE by C18 addition. Under optimized conditions, the method performances were evaluated; the limits of quantification (LOQs) achieved were lower than 0.689 μg kg^?1, and these values fit the performance criteria for the method given by the EC that defined the LOQ values of PAH lower than 0.9 μg kg^?1. In addition, the recovery values of the analyzed PAHs ranged from 88.9 to 119.3% with relative standard deviations (RSDs) less than 8% (n = 15). The levels of PAH4 were in the range from 1.52 to 49.9 μg kg^?1, where about 40% of the Lebanese grilled chicken exceeded the EU commission MRLs of 12 μg kg^?1.     

Lack of formation of heterocyclic amines in fumes from frying French fries

The formation of heterocyclic amines (HAs) in the fumes from frying French fries in soybean oil or lard was studied. A high-pressure liquid chromatography method was used to determine the various HAs in fumes. Results showed that the yields of fumes produced from soybean oil when heated alone for 2 or 4 h were higher than from lard; however, a reversed trend was found when frying French fries in soybean oil and lard. Most fumes from soybean oil and lard while frying French fries were adsorbed onto the condensation apparatus, while the other portions were adsorbed onto the wool and glass beads, which were incorporated in our experimental design for collecting the fumes. The fumes from soybean oil when heated alone were found to contain three HAs, namely, 2-amino-3-methylimidazo[4,5-f]quinoxaline (IQx), 2-amino-3-methylimidazo[4,5-f ]quinoline (IQ), and 1-methyl-9H-pyrido[4,3-b ]indole (Harman), whereas two more HAs, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b ]indole (Trp-P-1), were generated in lard. Lard was more susceptible to the formation of HAs than soybean oil when both were heated alone. No HAs were detected in the fumes from French fries fried in soybean oil and lard.     

Content of heterocyclic amines and polycyclic aromatic hydrocarbons in pork,beef and chicken barbecued at home by Danish consumers

It is a well-known fact that, when meat is barbecued, several harmful components, including heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH), may be formed. The aim of this study was to determine the HCA and PAH content in meat (pork, chicken and beef) when barbecued at home by Danish consumers according to their normal practice. With regard to HCA, beef contained the highest concentrations of 9H-pyrido[3,4-b]indole (norharman) and 2-methyl-β-carboline (harman), while chicken contained more 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) than pork and beef. The analysis of PAH showed a markedly higher concentration of PAH in beef compared with pork and chicken. In general, a correlation between the HCA content and the surface colour of the meat was found, the darker the colour the higher the HCA concentrations.     

Occurrence of bound 3-monochloropropan-1,2-diol content in commonly consumed foods in Hong Kong analysed by enzymatic hydrolysis and GC-MS detection

The aim of this study was to determine the level of bound 3-monochloropropan-1,2-diol in foodstuffs commonly consumed in Hong Kong, China, by an enzymatic hydrolysis indirect method which proved to be free from interferences. A total of 290 samples were picked up randomly from the local market and analysed. About 73% of these samples were found to contain detectable amounts of bound 3-MCPD. Amongst the 73 food items, bound 3-MCPD was not detected in 13 food items, including extra virgin olive oil, beef ball/salami, beef flank, ham/Chinese ham, nuts, seeds, soy sauce, oyster sauce, butter, yoghurt, cream, cheese and milk. For those found to contain detectable bound 3-MCPD, the content ranged up to 2500 µg kg^?1. The highest mean bound 3-MCPD content among the 14 food groups was in biscuits (440 [50–860] µg kg^?1), followed by fats and oils (390 [n.d.–2500] µg kg^?1), snacks (270 [9–1000] µg kg^?1), and Chinese pastry (270 [n.d.–1200] µg kg^?1). Among the samples, the highest bound 3-MCPD content was in a grape seed oil (2500 µg kg^?1), followed by a walnut flaky pastry (1200 µg kg^?1) and a grilled corn (1000 µg kg^?1). Basically, the results of this study agreed well with other published results in peer-reviewed journals, except for cheese, cream, ham, nuts and seeds.