Effects of ten vegetable oils on heterocyclic amine profiles in roasted beef patties using UPLC-MS/MS combined with principal component analysis.

Soybean oil (SBO), rapeseed oil (RSO), peanut oil (PO), corn oil (CO), olive oil (OO), sunflower oil (SFO), rice germ oil (RGO), walnut oil (WO), torreya seed oil (TSO), and grapeseed oil (GSO) were used to investigate the formation of heterocyclic amines (HAs) in roasted beef patties. Seven HAs, including 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4-dimethyl-3H-imidazo[4,5-f]quinolone (MeIQ), 2-amino-3-methyl-3H-imidazo[4,5-f]quinoxaline (IQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-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) were detected in control patties and patties with vegetable oils. GSO, SFO, and WO greatly reduced the content of PhIP and MeIQ. 1.25%TSO and 3.75% RGO showed higher inhibition effects on the more strongly mutagenic compounds (PhIP, MeIQ, IQx, 4,8-DiMeIQx, MeIQx). SBO, PO, and RSO promoted imidazoquin(ox)aline (MeIQ, MeIQx, 4,8-DiMeIQx, and IQx) and ß-carboline (harman and norharman); 1.25% SBO had the most significant promoting effect on total HA. This could be useful for the reduction of HA by selecting oils during cooking.

Residue Behavior and Risk Assessment of Rimsulfuron and Quizalofop-P-ethyl in Potato Under Field Conditions.

A method for simultaneous quantitation of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in potato plant, soil and potato tuber samples was established. The mean recoveries of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in different matrices spiked with them were 81.4%-101.1%, 76.1%-99.0% and 77.4%-106.4% with relative standard deviations (RSDs) of 2.7%-13.3%, 0.9%-5.5%, 1.7%-11.3%, respectively. The open-field trials in China were conducted in potato cultivation system of Changchun and Jinan. The results indicated that the half-lives of rimsulfuron and quizalofop-P-ethyl were 0.04-13.1 days. The residues of quizalofop-P during the harvest time in Jinan soil were < 0.01-0.044 mg kg-1, while there was no residue of target herbicides detected in all other samples. The risk assessment results demonstrated that the risk quotients (RQs) of rimsulfuron and quizalofop-P-ethyl were 7.857 × 10-5 and 8.730 × 10-3, respectively, which exhibited an acceptable dietary risk to Chinese consumers.

Dietary exposure assessment of cyadox based on tissue depletion of cyadox and its major metabolites in pigs, chickens, and carp.

The tissue kinetics of cyadox, an antibacterial agent used in food animals, and its major metabolites in pigs, chickens, and carp were investigated followed by a complete dietary exposure assessment to evaluate the food safety of cyadox. Cyadox and its major metabolites, bisdeoxycyadox (Cy1), 4-desoxycyadox (Cy2), N-(quinoxaline-2-methyl)-cyanide acetyl hydrazine (Cy4), quinoxaline-2-carboxylic acid (Cy6), and 2-hydromethyl-3-hydroxy-quinoxaline (Cy12), were simultaneously quantitated with a high-performance liquid chromatography-ultraviolet (HPLC-UV) method. Pigs, chickens, and carp were fed with 150 mg/kg cyadox in feed for consecutive 60, 40, and 30 days, respectively. The residue amount of cyadox and its major metabolites in liver, kidney, muscle, and fat (skin) tissues was determined. Cy2 was below the limit of quantitation even at the withdrawal time of 6 hr, cyadox, Cy4, Cy6, and Cy12 could be detected at 6-24 hr with low level less than 50 µg/kg. By contrast, Cy1 persisted for 3 days in the kidney of pigs and chickens, and in the liver of carp. Based on these residue depletion data and previous toxicology results, the global estimated chronic dietary exposure assessment of cyadox for general population was conducted, indicating a zero withdrawal time (WDT) may be appropriate for cyadox in food animals when used in feed for prolonged administration. These results provide analytical techniques and safety standards suitable for residue monitoring of cyadox in food animals.

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.

Formation of heterocyclic amines in salami and ham pizza toppings during baking of frozen pizza.

Heterocyclic amines (HAs) are formed as Maillard reaction products in the crust of meat products during heating processes. Two typical pizza toppings--salami and cooked ham--were analyzed for the presence of HAs after baking frozen pizzas at top and bottom temperatures of 250 and 230 °C, respectively. After baking pizza slices for 12 min, MeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline; 0.2 ng/g), 4,8-DiMeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline; 0.5 ng/g), PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine; 0.2 ng/g), norharman (4.5 ng/g), and harman (2.5 ng/g) were found in the ham toppings, whereas only the comutagenic norharman (107.4 ng/g) and harman (11.4 ng/g) were found in the salami toppings. The content of MeIQx and 4,8-DiMeIQx in ham increased from 0.3 to 1.8 ng/g and 0.8 to 1.6 ng/g, respectively, when the recommended baking time was increased from 15 min (manufacturer's specification) to 18 min at 230 °C. MeIQx was formed in salami when the heating time was extended to 18 min. Moreover, higher concentrations of PhIP in salami or ham slices were found when baking temperatures were 250 °C rather than 230 °C (baking time of 12 min). However, sensory tests showed that panelists preferred longer-baked pizzas due to an increased crispiness. Thus, results show that a substantial formation of HAs may occur in pizza toppings such as ham and salami, with ham being particularly susceptible when compared to salami. Formation of HAs increases with increasing baking time and temperature. The occurrence of the cupping of ham or salami slices during baking may also increase the formation of HAs.

Residual behavior of quizalofop ethyl on onion (Allium cepa L.).

Quizalofop ethyl, a phenoxy propionate herbicide, is used for postemergence control of annual and perennial grass weeds in broad-leaved crops in India. The experiments were designed to study the dissipation kinetics of quizalofop ethyl on onion for two seasons. A simple, rapid, and sensitive method for estimation of quizalofop ethyl residues in onion and soil was developed and validated. The recoveries of quizalofop ethyl residues from onion and soil at different spiking level range from 84.81 to 92.68 %. The limit of quantification of this method was found to be 0.01 µg g(-1). The risk assessment through consumption of the onion in comparison to its acceptable daily intake which is an important parameter for the safety of the consumer was also evaluated. Standardized methodology supported by recovery studies was adopted to estimate residues of quizalofop ethyl on onion and soil. The average initial deposits of quizalofop ethyl on onion were observed to be 0.25 and 0.33 mg kg(-1), following single application of the herbicide at 50 g active ingredient (a.i.) ha(-1) during 2009 and 2010, respectively. The half-life values (T (1/2)) of quizalofop ethyl on onion crop were worked out to be 0.85 and 0.79 days, respectively, during 2009 and 2010. At harvest time, the residues of quizalofop ethyl on onion and soil were found to be below the determination limit of 0.01 mg kg(-1) following single application of the herbicide at 50 and 100 g a.i. ha(-1) for both the periods.

Plant extracts, spices, and essential oils inactivate Escherichia coli O157:H7 and reduce formation of potentially carcinogenic heterocyclic amines in cooked beef patties.

Meats need to be heated to inactivate foodborne pathogens such as Escherichia coli O157:H7. High-temperature treatment used to prepare well-done meats increases the formation of carcinogenic heterocyclic amines (HCAs). We evaluated the ability of plant extracts, spices, and essential oils to simultaneously inactivate E. coli O157:H7 and suppress HCA formation in heated hamburger patties. Ground beef with added antimicrobials was inoculated with E. coli O157:H7 (10(7) CFU/g). Patties were cooked to reach 45 °C at the geometric center, flipped, and cooked for 5 min. Samples were then taken for microbiological and mass spectrometry analysis of HCAs. Some compounds were inhibitory only against E. coli or HCA formation, while some others inhibited both. Addition of 5% olive or apple skin extracts reduced E. coli O157:H7 populations to below the detection limit and by 1.6 log CFU/g, respectively. Similarly, 1% lemongrass oil reduced E. coli O157:H7 to below detection limits, while clove bud oil reduced the pathogen by 1.6 log CFU/g. The major heterocyclic amines 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) were concurrently reduced with the addition of olive extract by 79.5% and 84.3% and with apple extract by 76.1% and 82.1%, respectively. Similar results were observed with clove bud oil: MeIQx and PhIP were reduced by 35% and 52.1%, respectively. Addition of onion powder decreased formation of PhIP by 94.3%. These results suggest that edible natural plant compounds have the potential to prevent foodborne infections as well as carcinogenesis in humans consuming heat-processed meat products.

Inhibitory activity of Asian spices on heterocyclic amines formation in cooked beef patties.

Heterocyclic amines (HCAs) are mutagenic compounds formed when foods are cooked at high temperatures. Numerous reports have shown that natural antioxidants from spices, fruits, chocolate, and tea can inhibit formation. In this study, we evaluated HCA formation in the presence of 5 of Asian spices: galangal (Alpinia galangal), fingerroot (Boesenbergia pandurata), turmeric (Curcuma longa), cumin (Cuminum cyminum), and coriander seeds (Coriandrum sativum). HCA levels were compared to patties containing rosemary (Rosmarinus officinalis), of which the inhibitory effect is well documented. Inhibition of HCA formation by the spices was evaluated in beef patties cooked at 204 °C (400 °F) for 10 min. All spices were mixed into patties at 0.2% before cooking, and HCAs levels were measured in the final product. All patties, including the control, contained 2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl -6-phenylimidazo [4,5-b]pyridine (PhIP). The average HCA content of the control patties was 7 ng/g MeIQx and 6.53 ng/g PhIP. Turmeric (39.2% inhibition), fingerroot (33.5% inhibition), and galangal (18.4% inhibition) significantly decreased HCAs compared with the control. But, only turmeric and fingerroot were as effective as rosemary in preventing HCA formation. The HCA inhibition in patties containing spices was significantly correlated to the total phenolic content (R(2) = 0.80) and the scavenging activity (R(2) = 0.84) of the spices as measured by the 2,2-diphenyl-ß-picrylhydrazyl assay. Results of this study suggest that addition of Asian spices can be an important factor in decreasing the levels of HCAs in fried beef patties.

Inhibition of heterocyclic amine formation in beef patties by ethanolic extracts of rosemary.

Heterocyclic amines (HCAs) are mutagenic compounds formed during cooking muscle foods at high temperature. Inhibition of HCAs by rosemary extracts were evaluated with beef patties cooked at 191 degrees C (375 degrees F) for 6 min each side and 204 degrees C (400 degrees F) for 5 min each side. Five rosemary extracts extracted with different solvents were used in this study: extract 100W (100% water), 10E (10% ethanol), 20E (20% ethanol), 30E (30% ethanol), and 40E (40% ethanol). The 5 extracts were directly added to beef patties at 3 levels (0.05%, 0.2%, and 0.5%) before cooking and HCA contents were extracted and quantified. All of the patties contained 2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline (MeIQx), and 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP). There was no statistical difference in the inhibition of HCAs in the 0.05%, 0.2%, and 0.5% rosemary extracts. All rosemary extracts significantly decreased the levels of MeIQx and PhIP at both cooking conditions. When cooking at 204 degrees C (400 degrees F) for 5 min each side, rosemary extracts 10E and 20E were superior to rosemary extracts 100W, 30E, and 40E in inhibiting HCA formation. Rosemary extract 20E showed the greatest inhibition of MeIQx (up to 91.7%) and PhIP (up to 85.3%). The inhibiting effect of rosemary extracts on HCA formation corresponded to their antioxidant activity based on a DPPH scavenging assay. Rosemary extract 10E and 20E contain a mixture of rosmarinic acid, carnosol, and carnosic acid. It is possible that these compounds might act synergistically in inhibiting the formation of HCAs.

Effect of oil marinades with garlic, onion, and lemon juice on the formation of heterocyclic aromatic amines in fried beef patties.

Effects of the application of oil marinades with garlic, onion, and lemon juice on the formation of heterocyclic aromatic amines (HAAs) in fried beef patties were investigated. Two different statistical design models were used. In the screening experiment, a significant inhibition of formation of MeIQx was determined only by addition of garlic (p < 0.05). When the amount of garlic was changed from 2 to 20 g/100 g of marinade, the estimated MeIQx content in patties was reduced about 70%. MeIQx (0.38-1.22 ng/g), 4,8-DiMeIQx (n.d.-0.45 ng/g), PhIP (n.d.-0.09 ng/g), norharman (0.76-13.5 ng/g), and harman (2.9-21.5 ng/g) were found in fried patties. The results of two-level and three-level fractional factorial design experiments confirmed the first investigation. They showed a stronger reduction in MeIQx in patties with the addition of increasing amounts of garlic (p < 0.01) and onion (p < 0.05) in marinades. A higher content of lemon juice in marinades led to only a marginal reduction in MeIQx (p > 0.05). The optimum amounts of onion, garlic, and lemon juice that achieved a maximum reduction of HAAs were calculated as 31.2%, 28.6%, and 14.6% in marinade.

Biodegradability of metronidazole, olaquindox, and tylosin and formation of tylosin degradation products in aerobic soil--manure slurries.

The use of veterinary drugs (primarily antibiotics) in animal husbandry harbors the risk that these compounds end up in the farmland when manure is used as fertilizer. The biodegradability of three compounds, olaquindox (OLA), metronidazole (MET), and tylosin (TYL), was simulated in soil--manure slurries with 50 g of soil per liter. Supplemental batch sorption tests revealed that insignificant amounts of OLA and MET were located in the soil phase, whereas only 0.1 to 10% of the added amounts of TYL remained in the liquid phase. This may reduce the bioavailability and thus biodegradation rates of TYL. Unidentified metabolites of OLA and TYL and four known TYL metabolites were detected using HPLC. However, none of these substances were seen to persist in the biodegradation experiments, indicating that OLA and TYL most likely were mineralized in the experiments. Neither the use of sandy or clayey soil nor the use of 0, 1, or 10% (V/V) of manure added to these soils had a significant effect on the degradation rates. Degradation half-lives for the primary degradation were 3.3--8.1 days for TYL, 5.8--8.8 days for OLA, and 13.1--26.9 days for MET. Based on comparisons of results obtained with the benchmark chemical aniline and degradation half-lives of this compound in nature, it was assessed that results obtained with the current test method slightly overestimate real-world biodegradation rates.

Simple and sensitive determination of methylglyoxal in biological samples by gas chromatography with electron-capture detection.

Methylglyoxal was allowed to react with 4,5-dichloro-1,2-phenylenediamine, and the 6,7-dichloro-2-methylquinoxaline formed was determined by gas chromatography with electron-capture detection. The standard curve of the quinoxaline was linear up to 160 pmol/ml. The recoveries of methylglyoxal from coffee and rat liver homogenate were 84.1 and 77.6%, respectively. This procedure was very selective and so sensitive that as little as 9 fmol of the quinoxaline could be measured in biological and food samples.