Profiles and concentrations of heterocyclic aromatic amines formed in beef during various heat treatments depend on the time of ripening and muscle type

Quantification of hetero-cyclic amines from different categories of braised beef by optimized UPLC-TQ-XS/ESI method

This research work has developed and optimized a sensitive analytical method for separation and quantification of heterocyclic amines (HCAs) mainly including PhIP, Harman, Norharman, IQ, MeIQ, AαC, MeAαC and Trp-P-2 by optimizing UPLC-TQ-XS using electrospray ionization source (ESI+) on ACQUITY UPLC® BEH C18 column in <7 min, from braised beef sample matrix. Meanwhile, modified HCAs extraction by modifying QuEChERS (quick, easy, cheap, efficient, rugged and safe) technique and revisited with solid phase extraction (SPE) for HCAs purification, instead using traditional QuEChERS salts. Moreover, optimized pH conditions of HCA extracts before purification, for better extraction recoveries. Furthermore, this method was validated in terms of method validation parameters. Lastly, simulation of real braised beef model provided the minimum formation of HCAs by optimizing cooking parameters and precursors in a cooking system. Therefore, this method could be applied simultaneously on braised beef matrix either marketed or home cooked for HCAs analysis.

Determination of heterocyclic amines in braised sauce beef and the effects of different cooking conditions on the formation of heterocyclic amines

BACKGROUND

Cooked meat is a good source of high-quality protein. However, during long-term cooking of meat, radical-induced lipid and protein oxidation may lead to the formation of poisonous compounds, such as heterocyclic amines (HAs). This work investigated a testing method for HAs and it describes that cooking temperature, cooking time and repeated cooking times have influences on the overall quality of braised sauce beef and the effect of HAs formation.

RESULTS

The improved method has a good separation effect on nine kinds of HAs. The average recovery of HAs at two spiked levels is between 51.70% and 88.25% (n = 6). The detection limit is 0.025-0.060 ng g^-1 , and the limit of quantitation is 0.070-0.160 ng g^-1 . Only harman and norharman were detected in samples. Cooking time and cooking temperature will affect the quality and HA content of samples. When the braised sauce beef soup was cooked 20 times, the HA content was the highest - as high as 21.43 ng g^-1 . The more times the beef was cooked repeatedly, the higher was the HA content. Under different cooking conditions, glucose has a significant effect on the formation of β-carboline.

CONCLUSION

We have established a detection method for HAs with good repeatability and accuracy. HAs were more easily formed in braised sauce beef by high temperature, long heating and repeated brine cooking. © 2021 Society of Chemical Industry.

Influence of Partial Replacements of NaCl by KCl on Quality Characteristics and the Heterocyclic Aromatic Amine Contents of Bacon

The influence of partial replacements of NaCl by KCl (0, 10, 20, and 30%) on the heterocyclic aromatic amine (HAAs) contents and quality characteristics of bacon were investigated. The Na⁺ content, moisture, a_w, pH, L* value, and sensory saltiness decreased and K⁺ content, a* value, and sensory bitterness increased significantly with increased substituting rates of NaCl by KCl (p < 0.05). There were no significant differences between the control and KCl substitution samples for the b* value, redness, and sensory off-odor (p > 0.05). The creatine content was not affected by the different KCl-substituting rates during the marinating process (p > 0.05), but it diminished in the smoking and frying processes (p < 0.05). The increase in the KCl-substituting rates increased the total heterocyclic aromatic amine (HAA) contents in fried bacon (p < 0.05). Moreover, the nonpolar HAA content in bacon was higher than the polar HAA content (p < 0.05). In summary, the partial replacement of NaCl by KCl increased the total HAA content and led to changes in bacon quality.

Influence of Different Cooking Methods on Fillet Steak Physicochemical Characteristics

Meat is a source of protein widely consumed by the population in many countries due mainly to the nutritional aspects, sensory characteristics, and cultural aspects. The meat cooking preparation can promote significant changes in the meat's chemical composition and physical characteristics. Such transformations can impact both the acceptance of the product and consumers' health. Due to the different thermal processes altering the physical-chemical characteristics of meat, the present study aimed to evaluate the physicochemical characteristics of fillet steak submitted to different cooking methods: pan-frying with and without oil and air fryer. We performed the analysis to evaluate the physicochemical characteristics considering moisture, lipid, protein, ash, sodium, and potassium content, cooking loss index and colorimetry in three degrees of doneness of the meat, rare, medium, and well done. The fillet steak prepared by pan-frying with oil lost higher moisture and weight than the other samples. The air fryer method presented the highest moisture content. There was a significant difference in lipid content in which the pan-frying with oil fillet steak showed the highest amount of lipids. The pan-frying with oil steak fillet also presented more changes in the colorimetric parameters evaluated compared to the other samples. The pan-frying with oil cooking method promoted more pronounced changes in the steak fillet, and the cooking air fryer, the changes in meat quality are less pronounced. Therefore, the air fryer can be considered a good alternative for cooking meat.

Effect of Freeze-Thaw Cycles on the Oxidation of Protein and Fat and Its Relationship with the Formation of Heterocyclic Aromatic Amines and Advanced Glycation End Products in Raw Meat

The aim of this research was to investigate the effect of the number of freeze–thaw cycles (0, 1, 3, 5, and 7) on porcine longissimus protein and lipid oxidation, as well as changes in heterocyclic aromatic amines (HAAs) and advanced glycation end products (AGEs) and their precursors. We analyzed the relationship among HAAs, AGEs, oxidation, and precursors and found the following results after seven freeze–thaw cycles. The HAAs, Norharman and Harman, were 20.33% and 16.67% higher, respectively. The AGEs, Nε-carboxyethyllysine (CEL) and Nε-carboxymethyllysine (CML), were 11.81% and 14.02% higher, respectively. Glucose, creatine, and creatinine were reduced by 33.92%, 5.93%, and 1.12%, respectively after seven freeze–thaw cycles. Norharman was significantly correlated with thiobarbituric acid reactive substances (TBARS; r² = 0.910) and glucose (r² = −0.914). Harman was significantly correlated to TBARS (r² = 0.951), carbonyl (r² = 0.990), and glucose (r² = −0.920). CEL was correlated to TBARS (r² = 0.992) and carbonyl (r² = 0.933). These changes suggest that oxidation and the Maillard reaction during freeze–thaw cycles promote HAA and AGE production in raw pork.

The Inhibitory Effects of Heterotrigona Itama Honey Marinades on the Formation of Carcinogenic Heterocyclic Amines in Grilled Beef Satay

Heterocyclic amines (HCAs) are carcinogenic food toxicants formed in cooked meats, which may increase the risk of cancer development in humans. Therefore, in this study, the effect of stingless bee honey from different botanical origins on the formation of HCAs in grilled beef satay was investigated. HCAs concentration in grilled beef satay was determined by using high performance liquid chromatography (HPLC). In total, six of the most toxigenic HCAs representing aminoimidazo-azaarenes (AIAs) (MeIQx, 4,8-DiMeIQx, and PhIP) and amino carbolines (norharman, harman, and AαC) groups were identified in all the beef samples investigated. A significant reduction in HCAs was observed in grilled beef marinated in honey as compared to beef samples marinated in table sugar (control), in which the reduction of 95.14%, 88.45%, 85.65%, and 57.22% was observed in gelam, starfruit, acacia, and Apis honey marinades, respectively. According to the partial least squares regression (PLS) model, the inhibition of HCAs in grilled beef was shown to be significantly correlated to the antioxidant activity (IC50) of the honey samples. Therefore, the results of this study revealed that the addition of stingless bee honey could play an important role in reducing HCAs in grilled beef.

Predictive Correlation between Apparent Sensory Properties and the Formation of Heterocyclic Amines in Chicken Breast as a Function of Grilling Temperature and Time

In the present set of experiments, we studied the correlation between the heterocyclic amine (HCA) concentration and the color changes of the chicken breast with or without skin during grilling under open or closed conditions as a function of the applied temperature and time. The concentration of the HCAs formed during grilling was measured by a validated LC–MS/MS method, whereas the color changes were determined either instrumentally or by visual observation. In general, higher temperatures and longer heat treatment times resulted in a more substantial HCA formation, especially on the surface of the samples and in the skin, where the total levels reached 746 ng/g. Results of regression analysis demonstrate a strong correlation (r > 0.7) between the HCA content of the grilled chicken breast and the L* and a* values indicating the significance of brightness and the red parameter of the color scale, respectively. In the case of open grilling, the skinless breast samples showed correlation (r > 0.7) between the HCA content and the color analysis results in both the full sample and the crust, respectively. Breast samples with skin exhibited the same level of correlation when they were grilled closed. In the case of open grilling the breast with skin, and closed-grilling the skinless breast, the linear regression analysis yielded a weaker correlation (0.7 > r > 0.4 or less) between the HCA concentrations and the color. Our results demonstrate that there is a predictive correlation between the color changes perceptible for the consumers and the HCA formation during grilling of chicken breast as a function of time and temperature depending on the type of grilling and the presence of skin.

Inhibition effects of flavonoids on 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline formation and alkoxy radical scavenging capabilities of flavonoids in a model system

BACKGROUND

Heterocyclic aromatic amines (HAAs) have been considered as carcinogenic and mutagenic chemicals generated during thermal processing of protein-rich foods that can be inhibited by some flavonoids. Free radical scavenging is a major characteristic of flavonoids.

RESULTS

The half-maximal inhibitory concentration (IC₅₀ ) values of nine flavonoids were determined by evaluating their capacity to inhibit 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx) formation in a model system. The results of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) test validated that MeIQx and 7,8-DiMeIQx formed via a free radical pathway. Electron spin resonance (ESR) spectroscopic analysis with spin trapping (α-(4-pyridyl N-oxide)-N-tert-butylnitrone (POBN) spin adduct, a_N  = 15.2 G and a_H  = 2.7 G) revealed that an alkoxy radical was the generated intermediate. The scavenging capacities of the nine flavonoids on alkoxy radicals were then evaluated based on the ESR spectra of the POBN spin adducts.

CONCLUSION

The weak correlation between the alkoxy radical scavenging capacities and IC₅₀ of the flavonoids suggested that their inhibitory activity against MeIQx and 7,8-DiMeIQx formation operates by a more complex mechanism than simply scavenging alkoxy radicals. © 2017 Society of Chemical Industry.

Inhibitory profiles of spices against free and protein-bound heterocyclic amines of roast beef patties as revealed by ultra-performance liquid chromatography-tandem mass spectrometry and principal component analysis

The effects of various levels of chili pepper, Sichuan pepper, and black pepper on the amounts of 17 heterocyclic amines (HAs) from seven categories of both free and protein-bound states in roast beef patties were assessed by ultra-performance liquid chromatography-tandem mass spectrometry combined with principal component analysis. Three groups of HA, including imidazopyridines (DMIP), imidazoquinoxalines (MeIQx and 4,8-MeIQx), and β-carbolines (norharman and harman), were detected and quantified in both their free and protein-bound states, whereas PhIP was detected only in its free state, and imidazoquinolines (IQ, IQ[4,5-b], and MeIQ), α-carbolines (AαC and MeAαC), and phenylpyridines (Phe-P-1) were detected only in their protein-bound states. The results demonstrate that the peppers at all three levels had significant inhibitory effects on free PhIP, DMIP, MeIQx, and 4,8-DiMeIQx and could promote free norharman. Harman was significantly suppressed by chili pepper and black pepper, but enhanced by Sichuan pepper. All 11 protein-bound HAs, with the exception of IQ, IQ[4,5-b], and MeIQx with added chili pepper, were significantly reduced by the three peppers. The total amounts of the free and protein-bound states of all 11 HAs (1692.4 ± 78.9 ng g^-1), imidazopyridines (5.5 ± 0.2 ng g^-1), imidazoquinolines (7.2 ± 0.2 ng g^-1), imidazoquinoxalines (6.9 ± 0.2 ng g^-1), α-carbolines (20.1 ± 0.4 ng g^-1), and β-carbolines (1651.7 ± 79.5 ng g^-1) were suppressed by each level of all of the three peppers except for 0.5% and 1.0% chili pepper. Our findings may facilitate the inhibition of HA formation in the processing of meat products.

Domestic Cooking of Muscle Foods: Impact on Composition of Nutrients and Contaminants

Meat and fish are muscle foods rich in valuable nutrients, such as high-quality proteins, vitamins, and minerals, and, in the case of fish, also unsaturated fatty acids. The escalation of meat and fish production has increased the occurrence of pesticide and antibiotic residues, as result of pest control on feed crops, and antibiotics used to fight infections in animals. Meat and fish are usually cooked to enrich taste, soften texture, increase safety, and improve nutrient digestibility. However, the impact of cooking on nutritional properties and formation of deleterious compounds must be understood. This review summarizes studies, published in the last decade, that have focused on how domestic cooking affects: (i) composition of nutrients (protein, fatty acids, vitamins, and minerals); (ii) antibiotic and pesticide residue contents; and (iii) the formation of cooking-induced contaminants (heterocyclic aromatic amines, polycyclic aromatic hydrocarbons, and thermal degradation products of antibiotics and pesticides). Cooking affects the nutritional composition of meat and fish; frying is the cooking method that causes the greatest impact. Cooking may reduce the pesticide and antibiotic residues present in contaminated raw meat and fish; however, it may result in the formation of degradation products of unknown identity and toxicity. Control of cooking time and temperature, use of antioxidant-rich marinades, and avoiding the dripping of fat during charcoal grilling can reduce the formation of cooking-induced contaminants.

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

BACKGROUND

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

RESULTS

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

CONCLUSION

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

Formation of heterocyclic amines in Chinese marinated meat: effects of animal species and ingredients (rock candy, soy sauce and rice wine)

BACKGROUND

Heterocyclic aromatic amines (HAAs) are one type of neo-formed contaminants in protein-rich foods during heat processing. Recently, accumulative studies have focused on the formation of HAs in Western foods. However, there is little knowledge about the occurrence of HAAs in traditional Chinese foods. The objective of this study was to determinate the contents of main HAs in traditional marinated meat products by UPLC-MS/MS, and to investigate the effects of animal species and the ingredients (soy sauce, rock candy, and rice wine) on the formation of HAAs in marinated meats.

RESULTS

Five HAs - 2-amino-3-methylimidazo[4,5-f]-quinolone (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4-dimethylimidazo[4,5-f]quinoxaline (MeIQ), 9H-pyrido[3,4-b]indole (Norharman) and l-methyl-9H-pyrido[3,4-b]indole (Harman) - were detected in 12 marinated meats, but 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was only found in three chicken marinates. The animal species and ingredients (soy sauce, rock candy and rice wine) have significant influence on the formation of HAAs in meat marinates. Beef had the highest content of total HAAs compared with pork, mutton and chicken. Meanwhile, soy sauce contributed to the formation of HAAs more greatly than rock candy, soy sauce, and rice wine.

CONCLUSION

Choice of raw materials and optimisation of ingredients recipe should be become a critical point to control the HAAs formation in marinated meats. © 2017 Society of Chemical Industry.

Metabolism of Foodborne Heterocyclic Aromatic Amines by Lactobacillus reuteri DSM 20016

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

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

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

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

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

Mechanisms Linking Colorectal Cancer to the Consumption of (Processed) Red Meat: A Review

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world. The vast majority of CRC cases have been linked to environmental causes rather than to heritable genetic changes. Over the last decades, epidemiological evidence linking the consumption of red and, more convincingly, of processed red meat to CRC has accumulated. In parallel, hypotheses on carcinogenic mechanisms underlying an association between CRC and the intake of red and processed red meat have been proposed and investigated in biological studies. The hypotheses that have received most attention until now include (1) the presence of polycyclic aromatic hydrocarbons and heterocyclic aromatic amines, two groups of compounds recognized as carcinogenic, (2) the enhancing effect of (nitrosyl)heme on the formation of carcinogenic N-nitroso compounds and lipid peroxidation. However, none of these hypotheses completely explains the link between red and processed red meat intake and the CRC risk. Consequently, scientists have proposed additional mechanisms or refined their hypotheses. This review first briefly summarizes the development of CRC followed by an in-depth overview and critical discussion of the different potential carcinogenic mechanisms underlying the increased CRC risk associated with the consumption of red and processed red meat.

Effects of waxy rice starch and short chain amylose (SCA) on the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in a model system

A possible mechanism of waxy rice starch and SCA for inhibiting PhIP formation in the model system is also proposed.

Global metabolite profiling and diagnostic ion filtering strategy by LC-QTOF MS for rapid identification of raw and processed pieces of Rheum palmatum L

Due to its variety of functions, rhubarb has been used for thousands of years in many countries. It is commonly used after processing. Processing usually affect the chemical profile and the contents of active compounds in herbals, leading to changes of their bioactivities. Here, an approach of metabolite profiling and diagnostic ion filtering strategy with liquid chromatography-quadrupole/time-of-flight mass spectrometry was established for rapid identification of raw and processed pieces of Rheum palmatum L. (RPL). The comprehensive and unbiased information of 30 batches of RPL covering raw and two general processing methods were given by metabolomic profiles. Using molecular feature extraction algorithm, non-targeted compounds were analyzed in minutes. In total, 73 characteristic markers were extracted and identified by diagnostic ion filtering. They have been further analyzed by partial least squares-support vector machine-based pattern recognition. The comprehensive and rapid method for raw and processed pieces of RPL classification shows good sensitivity, specificity and prediction performance.

Effect of cooking methods on cholesterol, mineral composition and formation of total heterocyclic aromatic amines in Muscovy drake meat

BACKGROUND

Cholesterol, minerals and heterocyclic aromatic amines (HAAs) are of great importance in determining meat quality to humans and therefore of concern to meat consumers because of health reasons. The objective of this study was to evaluate the effects of various cooking methods (grilling, deep frying, pan frying and roasting) on the formation of total HAAs, cholesterol and mineral retention in Muscovy drake breast meat. Total HAAs and cholesterol were determined by high-performance liquid chromatography, while minerals were measured by atomic absorption spectroscopy.

RESULTS

Muscovy drake breast meat cooked by deep frying had the highest content of total HAAs (31.83 ng g(-1)), followed by roasted (30.12 ng g(-1)), pan-fried (29.23 ng g(-1)) and grilled (27.34 ng g(-1)) fillets. The cholesterol content was highest in deep-fried fillets (59.09 mg g(-1)), followed by roasted fillets (58.61 mg g(-1)), while grilling resulted in the lowest cholesterol content (57.00 mg g(-1)). The mineral content was highest in deep-fried samples and lowest in roasted fillets. Magnesium retention was affected by the cooking method and was higher in deep-fried samples (110.57%) than in grilled (97.97%), pan-fried (88.99%) and roasted (78.46%) fillets. Generally, the total HAA, cholesterol and mineral content in cooked Muscovy drake breast meat varied with the cooking method.

CONCLUSION

Moderate consumption of deep-fried Muscovy drake meat should be encouraged, as deep frying increased its cholesterol, total HAA and mineral content compared with the other cooking methods investigated.

Simultaneous analysis of PhIP, 4'-OH-PhIP, and their precursors using UHPLC-MS/MS

A novel method allowing simultaneous analysis of PhIP, 4'-OH-PhIP, and their precursors (phenylalanine, tyrosine, creatine, creatinine, glucose) has been developed as a robust kinetic study tool by using ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A direct hydrochloric acid (HCl) extraction was applied to achieve the simultaneous extraction of all seven analytes, with the mean recoveries ranging from 60% to 120% at two concentration levels. Then, an Atlantis dC18 column selected from four different chromatographic columns was ultimately used to separate these compounds within 15 min. The limits of detection range of allseven analytes were calculated as 0.14-325.00 μg L(-1). The intra- and interday precision of the proposed method were less than 15.4 and 19.9%, respectively. The proposed method was successfully applied to depict the kinetic profiles of PhIP, 4'-OH-PhIP, and their precursors in pork model, reducing the analysis time and cost in the kinetic study.