Formation Of Heterocyclic Amines Research Articles

Antioxidants may reduce heterocyclic amines in commercially marinated beef steaks (2007)

Heterocyclic amines (HCAs) are carcinogenic and mutagenic compounds found at a level of parts per billion in grilled fish and meats. Since the connection between consumption of dietary carcinogens and risk of different cancers in humans has been established, it is necessary to explore effective inhibitors that can prevent or reduce the formation of HCAs in cooked meats. Cooking meat with natural antioxidants decreases or eliminates HCAs in meat. Our objective was to study the inhibition of five HCAs in beef steaks marinated using commercial ingredients that are natural antioxidants.

Effects of Rosemary Extracts on the Reduction of Heterocyclic Amines in Beef Patties

ABSTRACT: The effects of rosmarinic acid and a rosemary antioxidant powder were evaluated on the reduction and mutagenicity of MeIQx, PhIP, and comutagens norharman and harman in beef patties fried at 375 °F for 5 min each side and 400 °F for 7.5 min each side. Both rosemary extracts were found to effectively decrease the formation and overall mutagenic activity of heterocyclic amines (HCAs) due to their antioxidative characteristics. At the lower temperature, rosmarinic acid was able to reduce MeIQx by up to 64% and PhIP by 48%, while rosemary powder reduced the formations of MeIQx up to 69% and PhIP up to 66%. The effects of the rosemary extracts were more dramatic when cooking temperature and time were increased, as rosmarinic acid was able to reduce MeIQx formation up to 70% and PhIP up to 64%; also, rosemary powder significantly reduced MeIQx up to 57% and PhIP up to 77%. The overall mutagenic activity was evaluated by the Ames Salmonella assay and both rosemary extracts were capable of reducing mutagenicity in beef patties at the higher cooking temperature of 400 °F. At 375 °F there was an insignificant trend of the rosemary extracts decreasing the number of Salmonella revertants. There was no significant inhibiting effect by any of the rosemary extracts on the formation of either norharman and harman as measured in this study.

Effect of Red Wine Marinades on the Formation of Heterocyclic Amines in Fried Chicken Breast

Genotoxic heterocyclic amines (HAs) are formed via the Maillard reaction and free radical reaction mechanisms when meat or fish is cooked at usual cooking conditions. In this paper, the effect of the addition of red wine was tested to study if it interferes in HA formation. Fried chicken breast was the food item chosen, and three different red wines, characterized in terms of grape varieties, free amino acids, antioxidant properties, and metallic composition, were used to marinate meat prior to the heating process. Unmarinated samples and samples marinated with an ethanol-water mixture provided reference HA levels. The frying experiments were performed under well-controlled temperature and time conditions. The samples were analyzed for HA content using solid-phase extraction and LC-MS/MS. DMIP, PhIP, MeIQx, 4,8-DiMeIQx, IFP, TMIP, harman, and norharman were identified in fried chicken breast. Red wine marinades were found to reduce the formation of some of the HAs formed. PhIP, with a reduction of up to 88%, was the most minimized amine, although the formation of harman was enhanced.

Lack of Formation of Heteroyclic 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.

Heterocyclic Amines: 2. Inhibitory Effects of Natural Extracts on the Formation of Polar and Nonpolar Heterocyclic Amines in Cooked Beef

: The effects of natural extracts on the formation of polar (IQ, MeIQ, MeIQx, 4,8-DiMeIQx, and PhIP) and nonpolar (norharman, harman, and AαC) heterocyclic amines (HAs) were examined in ground beef cooked at 200 and 210°C for 20 min. In experiment 1, the formation of MeIQx was effectively reduced by 77%, 75%, and 69%, respectively, for 1.0% pine bark extract (Pycnogenol®), 1.0% Oleoresin rosemary (Herbalox®), and grape seed extract (ActiVinTM) at 200°C for 20 min. No 4,8-DiMeIQx was observed in the 1.0% ActiVin. When compared with the initial concentrations, glucose and creatine significantly decreased for all treatments and the control at 200°C after 20 min. In experiment 2, IQ was not formed in any treatment when beef was fried at 210°C for 10 min/side. The formation of MeIQx was reduced by 64% and 61% at 1.0% ActiVin and 1.0% Pycnogenol. Herbalox (1.0%) more effectively decreased the amount of nonpolar HAs than other treatments. No AαC and norharman were detected at 1.0 % Herbalox. Natural extracts, ActiVin, Pycnogenol, and Herbalox, effectively decreased the formation of polar and nonpolar HAs. The results provide valuable information to inhibit the formation of HAs in cooked meats.

Formation of Mutagenic/Carcinogenic Heterocyclic Amines under Moderate Conditions

More than 10 kinds of heterocyclic amines (HCAs), showing mutagenic and carcinogenic potency, have been isolated from cooked fish and meat. But many researchers say that the contribution ratio of HCAs to human cancer is very low. Our purpose in this experiment was to investigate the possibility of the formation of HCAs under moderate conditions, including in vivo. A mixture of d-glucose, creatinine, and amino acid such as glycine, methionine, threonine, and proline was dissolved in phosphate-buffered solution (pH7.4) and incubated at 37 degrees C, 50 degrees C, 128 degrees C. At an appropriate time, an aliquot of the reaction solution was treated with blue cotton. HCAs were separated from the blue cotton by elution with 2% ammoniacal methanol. The eluates were submitted to the Ames test, the micronucleus test for determination of mutagenicity, and also LC-MS analysis for the detection of HCAs. Nonadsorbates to blue cotton were treated with dichloromethane and then subjected to the mutagenicity test. In the Ames test, the mutagenic activity of the reaction mixture increased with an increase of the reaction temperature. The HCA fraction from 50 degrees C incubated solution showed high frequency in the micronucleus test using HepG2 cells. The dichloromethane fractions contained other type of mutagens different from HCAs. In HCA fractions, IQ, MeIQx, 4,8-DiMeIQx, and 7,8-DiMeIQ were identified. It is said that the heating process is an essential factor in the formation of HCAs. But our experiment shows that HCAs are produced not only in the cooking process, but also in moderate conditions such as 37 degrees C and 50 degrees C.

Formation and Human Risk of Carcinogenic Heterocyclic Amines Formed from Natural Precursors in Meat

A group of heterocyclic amines that are mutagens and rodent carcinogens form when meat is cooked to medium and well-done states. The precursors of these compounds are natural meat components: creatinine, amino acids, and sugars. Defined model systems of dry-heated precursors mimic the amounts and proportions of heterocyclic amines found in meat. Results from model systems and cooking experiments suggest ways to reduce their formation and, thus, reduce human intake. Human cancer epidemiology studies related to the consumption of well-done meat products are listed and compared in this review.

Formation and Human Risk of Carcinogenic Heterocyclic Amines Formed from Natural Precursors in Meat

A group of heterocyclic amines that are mutagens and rodent carcinogens form when meat is cooked to medium and well-done states. The precursors of these compounds are natural meat components: creatinine, amino acids, and sugars. Defined model systems of dry-heated precursors mimic the amounts and proportions of heterocyclic amines found in meat. Results from model systems and cooking experiments suggest ways to reduce their formation and, thus, reduce human intake. Human cancer epidemiology studies related to the consumption of well-done meat products are listed and compared in this review.

Heterocyclic Amines: 1. Kinetics of Formation of Polar and Nonpolar Heterocyclic Amines as a Function of Time and Temperature

ABSTRACT: The influence of time, temperature, glucose, and creatine on the formation of heterocyclic amines (HAs) in beef was investigated. Kinetic models as a function of time and temperature were used to examine the formation of polar and nonpolar HAs, as described by Arrhenius and Eyring equations. The highest amount of MeIQx was 23.93 ng/g at 220°C for 20 min. However, no formation of 4,8-DiMeIQx was observed at 160°C, 180°C, 200°C, and 220°C for 5 min. Norharman and 4,8-DiMeIQx were more sensitive to temperature change, whereas MeIQx and AαC were less sensitive. The formation of HAs increased with increasing time and temperature. Glucose and creatine decreased at the same pattern with increasing time and temperature. The formation of HAs and the degradation of precursors were inversely correlated. The results provide valuable information toward modulating and inhibiting the formation of HAs in cooked meats.

Addition of Various Carbohydrates to Beef Burgers Affects the Formation of Heterocyclic Amines during Frying

The influence of the addition of carbohydrates with different physicochemical properties on weight loss and formation of heterocyclic amines (HAs) during the frying of beef burgers was examined. Furthermore, the capability of carbohydrates to bind HAs was tested. Beef burgers containing 1.5% NaCl and 0.3% tripolyphosphate (reference), with the addition of 1.5% carbohydrate, were fried for 5 min at 200 degrees C in a double-sided pan fryer. The beef burgers were analyzed for HAs with solid phase extraction and liquid chromatography/mass spectrometry. 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-phenyl-imidazo[4,5-b]pyridine (PhIP), and 9H-pyrido[3,4-b]indole (Norharman) were detected in all of the beef burgers. The addition of carbohydrates affected both the weight loss and the formation of HAs during cooking. The formation of HAs could be correlated to depend on both the weight loss and the type of the added carbohydrate. Of the 11 different carbohydrates tested, raw potato starch was most capable of inhibiting the formation of HAs, while potato fiber gave the lowest weight loss and a comparably low amount of PhIP. Wheat bran and potato fiber were found to reversibly bind HAs. It is concluded that adding small amounts of certain carbohydrates may be a simple and effective way of reducing the amount of HAs and can easily be applied in households and commercial preparations of beef burgers.

Chemistry, formation and occurrence of genotoxic heterocyclic aromatic amines in fried products

AbstractHeterocyclic amines (HAs) are formed during heating of meat or fish. The precursors necessary for formation of these heterocyclic amines are amino acids that react with carbohydrates and creatinine. Creatinine is needed for the formation of polar amines with an imidazo‐quinoline or an imidazo‐quinoxaline structure. For the formation of the non‐polar amines no creatinine is needed. At temperatures of above 150 °C these substances are formed in the low ppb range. However, when the temperature is increased or the heating time is prolonged the concentration of the amines can reach levels of above 100 ppb. Heterocyclic amines are mutagenic in bacterial and animal test systems and carcinogenic in rodents. As the heterocyclic amines are not mutagenic by themselves they have to be activated with cytochrome P450 enzymes and N‐acetyl‐transferases or sulfotransferases. Epidemiological studies have revealed that the cancer risk is strongly associated with the uptake of thoroughly roasted meat in which the heterocyclic amines occur. As these substances are formed inherently, measures have to be taken to reduce the formation in meat or fish during cooking. These measures range from changing cooking habits to use with additives or breeding of animals with a genetically determined lower HA forming capability of the meat.

Potential sources of carcinogenic heterocyclic amines in the Chinese diet: results from a 24-h dietary recall study in Singapore.

Heterocyclic amines (HCAs) from high-temperature cooking of meat have been linked to increased cancer incidence in Western populations, but data on the sources of HCAs in Asian diets are scarce. Our aim was to identify potential sources of HCAs in the Chinese diet, and to provide the basis for efforts to quantify dietary exposure to these compounds. We conducted 24-h dietary recall interviews among 986 Chinese men and women in Singapore, who were a randomly selected subpopulation of participants from the Singapore Chinese Health Study, a population-based cohort. Details of all foods and beverages consumed by each subject in the past 24 h were recorded, and information on meat type, cooking method and portion size were abstracted from all meat-containing dishes, and gram weight equivalents computed. The mean meat intake per person was 103.0 g/day (standard deviation 74.2), of which 97.2% was fresh meat. Fish (38.0%), pork (30.6%), and poultry (21.0%) accounted for 89.6% of meat consumed. Patterns of meat consumption and cooking methods differed markedly from Western populations. Documented high-temperature cooking methods, combined with stir-frying, accounted for 44.3% of fish, 35.1% of pork and 25.6% of poultry consumed. Specifically, potentially significant sources of HCAs were pan-fried fish and barbecued pork. Our results identify the potential sources of HCA in the Chinese diet, highlight aspects which are relevant to HCA formation and intake, and call for novel approaches to estimating individual exposure to dietary HCAs in this and similar populations.

Evaluation of a new model system for studying the formation of heterocyclic amines

Heterocyclic amines (HAs) are an important class of food mutagens and carcinogens, which can be found in cooked meat and fish. Increasing heating temperatures and times usually increase mutagenic activity in meat and meat extracts during cooking. We developed a model system, which allows to examine the effects of precursor composition and heating conditions (time and temperature) on the formation of HAs in meat. Homogenized and freeze dried meat samples (beef, pork chops, chicken breast and turkey breast) are heated with diethylene glycol in closed vials under stirring in a thermostated heating block. After an appropriate sample preparation (extraction and clean-up) ten different HAs were measured by HPLC analyses with gradient elution and mass selective detection. The time courses of HA-formation in the different kinds of meat at varying heating temperatures were determined up to heating times of 30 min. 2-Amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP) was the most abundant HA in these experiments and reached the highest concentrations in the beef meat samples, as did the other HAs (MeIQ, AαC) at 220 °C in the heating block under stirred conditions. Additionally the influence of the antioxidant TBHQ ( t-butylhydroquinone) on the formation of HAs in the model system was tested. However TBHQ effected only slight reductions of HA formation in all kinds of meat.

Effects of heating time and antioxidants on the formation of heterocyclic amines in marinated foods

The effect of heating time and antioxidants on the heterocyclic amine (HAs) formation in marinated foods were studied. Food samples were cooked at 98±2 °C for 1, 2, 4, 8, 16 and 32 h in a closed pan in the presence of water, soy sauce and rock candy with or without antioxidants. The various HAs in marinated food samples and juice were analyzed by HPLC with photodiode-array detection. Results showed that the amount of HAs formed during heating followed an increased order for each increasing heating time. A larger variety and higher amount of HAs were generated in marinated pork when compared to marinated eggs and bean cake. In marinated juice, the levels of HAs were present in greater amount than in marinated foods. The incorporation of antioxidants Vitamin C, Vitamin E and BHT were found to be effective towards HAs inhibition, however, the effect was minor.

Formation and stability of heterocyclic amines in a meat flavour model system: Effect of temperature, time and precursors

A model system based on a commercial meat flavour was used to evaluate the formation of heterocyclic amines, simulating the application of this seasoning in household cooking. The effects of different treatments in both dry and aqueous conditions were studied. The lyophilized meat flavour extract was heated at temperatures ranging between 100 and 200 °C for times ranging from 10 min to 2 h. Similarly, an aqueous suspension of the extract was heated at 175 °C for 1, 2 and 3 h. Precursors of HAs, such as creatinine, glucose, and the amino acids glycine, alanine and phenylalanine were added to the meat extract and their effect was tested by heating the mixture at 200 °C for 30 min, when dry conditions were used, and at 175 °C for 2 h in wet systems. All conditions led to the formation of HAs, PhIP being the amine that was detected at the highest level of concentration in most model systems (i.e. 173 ng g −1 at 200 °C, 30 min). Moreover, the addition of creatinine and amino acids to the meat extract flavour produced an important increase in IQ and MeIQx content.

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-methyllmidazo[4, 5-f]quinoxaline), MeIQx (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 conditions.

Influence of antioxidants in virgin olive oil on the formation of heterocyclic amines in fried beefburgers

An association between the intake of heterocyclic amines (HAs) and the development of cancer has been observed in some epidemiological studies, while in other studies no such correlation has been found. HAs are mutagenic/carcinogenic compounds formed at low levels via the Maillard reaction and a free radical mechanism during cooking of animal tissue. The addition of pure antioxidants or foods containing antioxidants has previously been shown to decrease the amount of HAs formed during cooking. In this study, beefburgers were fried in six different oils: refined olive oil, virgin olive oil, virgin olive oil depleted of phenols, rapeseed oil, virgin olive oil with rosemary extract and refined olive oil with rosemary extract. The content of antioxidative compounds in the virgin olive oil and the rosemary extract was determined. The beefburgers were analysed with regards to 12 different HAs by solid phase extraction and HPLC analysis. MeIQx, 4,8-DiMeIQx, PhIP, Harman and Norharman were detected in all beefburgers fried in the different oils, but the relative amounts varied. Frying in virgin olive oil reduced the formation of HAs compared with refined olive oil. This effect is probably due to the content of phenols in the virgin olive oil. The HA-reducing effect of virgin olive oil decreased during storage, but the addition of rosemary extract may prevent this decrease.

Effect of high water-holding capacity on the formation of heterocyclic amines in fried beefburgers.

Mutagenic/carcinogenic heterocyclic amines (HAs) are formed in the crust during the cooking of meat. The influence of cooking loss, time, and temperature on the formation of HAs was investigated in fried beefburgers. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 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 identified in all samples. The amounts of PhIP, MeIQx, and 4,8-DiMeIQx increased with increasing cooking time, and this effect was significant for all three HAs. The pan temperature had a significant effect on the formation of PhIP and 4,8-DiMeIQx. The addition of NaCl/sodium tripolyphosphate to the beefburgers reduced the cooking loss and decreased the formation of PhIP, MeIQx, and 4,8-DiMeIQx. This decrease was significant for MeIQx and 4,8-DiMeIQx. The results clearly show that it is possible to modify cooking practices to minimize the formation of HAs.

Inhibition of heterocyclic amine formation in beef patties with added spices and ingredients

Heterocyclic amines (HCAs) are compounds present at part per billion levels in fried, grilled, broiled, barbecued and smoked meats. Most of these compounds are highly mutagenic, as demonstrated by the Ames test using Salmonella typhimurium. They also are carcinogenic in rodents and non-human primates following high dosage and long term oral administration. For decades, researchers have focused on inhibiting the production of these carcinogens. This research investigates the effects of natural antioxidants in spices or other ingredients on the reduction of heterocyclic amines formation when beef patties are cooked. The term “spice” in this paper includes herbs. Ground beef patties combined with different levels of added spices or ingredients were cooked at 375°F (5 minutes each side) or 400°F (7.5 minutes each side). Extracted HCAs were then analyzed using reversed-phase High Performance Liquid Chromatography (HPLC) with UV-Visible and fluorescence detectors. Of the spices used, basil added at 0.5% was most effective in decreasing HCAs. Of all the ingredients, food starches showed the best inhibition when added at 5% as they reduced MelQx, harman, and norharman forms of HCA at both 375°F and 400°F.

Formation of mutagenic and carcinogenic heterocyclic amines in the model systems without heating

Cooked food-borne heterocyclic amines (HCAs) show strong mutagenic activity toward Salmonella typhimurium TA98 strain in the presence of metabolic activation system. They also induce several kinds of tumors in mice and rats. Among them, 2-amino-3, 4-dimethylaminoimidazo [4,5-f] quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) are also isolated from a reaction mixture consisting of d-glucose, amino acid and creatinine by heating at 128 °C for 2 h. There is no report on the formation of HCAs under mild conditions. In the present study, a mixture of d-glucose, glycine and creatinine was dissolved in 0.2 M phosphate buffer solution (pH7.4) and kept at 37 °C for 84 days. Aliquots of the reaction solution were treated with blue cotton and the adsorbates were extracted with NH4OH–MeOH mixture. By applying the extract to HPLC and LC-MS analysis, MeIQx was isolated and identified. When phenylalanine was used instead of glycine in the above model system, PhIP was formed. These results show that heating process is not essential for the formation of HCAs. Therefore, HCAs may be formed in our body tissues and in the long storage of manufactured foods.