Content Of Heterocyclic Amines Research Articles

Evaluation of the potential of annatto seed powder to reduce the formation of heterocyclic amines in charcoal-grilled and pan-fried beef patties

Various strategies are being explored to reduce the formation of undesirable compounds during the thermal processing of foods. This study investigates the impact of incorporating annatto seed powder (Bixa orellana L.) into beef patties to reduce the formation of heterocyclic amines (HAs) during charcoal-grilling and pan-frying. A three-level full factorial design was used to assess the effect of both annatto seed powder concentration and cooking times on HAs formation. The results showed that HA formation increased with longer cooking times and decreased with higher concentrations of annatto seed powder. A significant reduction in HA content was observed in both charcoal-grilled and pan-fried beef patties when annatto seed powder was added, with a particularly notable 91 % reduction at the 1 % addition level. These findings demonstrate that the addition of annatto seed powder is a highly effective strategy for reducing HA formation in beef patties. Chemical compounds studied in this article2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (PubChem CID: 62275); 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) (PubChem CID: 104739); 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx) (PubChem CID: 104855); 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (PubChem CID: 1530); 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) (PubChem CID: 5284474); 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) (PubChem CID: 5284476); 2-amino-9H-pyrido[2,3-b]indole (AαC) (PubChem CID: 62805); 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAαC) (PubChem CID: 62244); Bixin (PubChem CID: 5281226).

Effects of potential key substances in woodchips smoldering smoke on the formation of heterocyclic amines and polycyclic aromatic hydrocarbons in Frankfurter sausages

The Frankfurter sausages smoked with beech, oak, and alder, respectively, were used to clarify the underlying impact of the smoke chemical composition on the levels of heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs). The result indicated that different wood types significantly affected the profiles of target substances in food matrices. The beech-smoked samples had lower contents of total free HAs (5.98–6.80 ng/g dry-weight-DW), PAH4 (3.31–3.83 ng/g DW), and PAH8 (10.0–10.8 ng/g DW), whereas the alder pyrolysis usually led to higher hazardous residues (8.26–9.19 ng/g DW of total free HAs, 4.24–6.60 ng/g DW of PAH4 and 14.1–23.3 ng/g DW of PAH8). In addition, the differences in smoke chemical composition were attributed to the different proportions of 15 key identified substances. Among them, two aldehydes (5-methyl-furfural & furfural) and two phenols (phenol & 5-hydroxymaltol) may have synergistic or competitive inhibitory effects on the formation of HAs and PAHs in smoked meat products.

Effects of Phenols from Olive Vegetation Water on Mutagenicity and Genotoxicity of Stored-Cooked Beef Patties.

This explorative study aimed to assess the mutagenicity and genotoxicity of stored-cooked beef patties formulated with and without phenols (7.00 mg of phenols/80-g patty) extracted from olive vegetation water (OVW), as related to the formation of cholesterol oxidation products (COPs) and heterocyclic amines (HCAs). The patties were packaged in a modified atmosphere, sampled during cold storage (4 °C) for 9 days, and grilled at 200 °C. The genotoxicity was evaluated by the Comet assay. The patty extract was found to be genotoxic on primary peripheral blood mononuclear cells (PBMCs), while no mutagenicity was detected. The addition of OVW phenols significantly decreased the genotoxicity of the patty extract and reduced the total COPs content in stored-cooked patties (4.59 times lower than control); however, it did not affect the content of total HCAs (31.51-36.31 ng/patty) and the revertants' number. Therefore, these results demonstrate that the OVW phenols were able to counteract the formation of genotoxic compounds in stored-cooked beef patties.

Effect of Chinese quince proanthocyanidins on the inhibition of heterocyclic amines and quality of fried chicken meatballs and tofu.

Heterocyclic amines (HCAs) have potential carcinogenic and mutagenic activity and are generated in cooked protein-rich foods. Adding proanthocyanidins (PAs) to these foods before frying is an effective way to reduce HCAs. In this study, polymeric PAs (PPA) and ultrasound-assisted acid-catalyzed/catechin nucleophilic depolymerized PAs (UAPA, a type of oligomeric PA) were prepared from Chinese quince fruits (CQF). Different levels of PPA and UAPA (0.05%, 0.1%, and 0.15%) were added to chicken meatballs and tofu; then these foods were fried, and the content of HCAs in them after frying was investigated. The results showed that PPA and, particularly, UAPA significantly inhibited the formation of HCAs in fried meatballs and tofu, and this inhibition was dose-dependent. The inhibition of HCAs by both PPA and UAPA was stronger in the chicken meatballs than in fried tofu. The level of total HCAs was significantly reduced by 57.84% (from 11.93 to 5.03ng/g) after treatment of meatballs with 0.15% UAPA, with inhibition rates of 78.94%, 50.37%, and 17.81% for norharman, harman, and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), respectively. Of note, there was a negative correlation between water, lipid, protein, creatine, and glucose content and HCA content in the crust, interior, and whole (crust-plus-interior) measurements of all fried samples. Interestingly, PPA and UAPA were found more effective in inhibiting HCAs in the exterior crust than in the interior of the fried chicken meatballs. These results provide evidence that further studies on the reduction of the formation of harmful HCAs in fried foods by adding CQF PAs could be valuable to the fried food industry. PRACTICAL APPLICATION: Chinese quince proanthocyanidins treatments significantly inhibited the generation of heterocyclic amines (HCAs) in chicken meatballs and tofu when deep-fried. These results suggest that Chinese quince proanthocyanidins can be used as natural food additive for reducing HCAs in fried foods, laying the foundation for using Chinese quince fruit proanthocyanidins for HCA inhibition in the food industry.

Effects of grilling conditions on heterocyclic amines and quality attributes of grilled grass carp

SummaryThe effects of different grilling temperatures (220 °C, 250 °C, 280 °C, 310 °C) reaching the central temperature of 70 °C on heterocyclic amines (HAs) formation, moisture content, cooking loss, texture, colour, and sensory properties of grilled grass carp (Ctenopharyngodon idella) were investigated. The grilling condition significantly (P < 0.05) affected cooking loss, moisture content, heterocyclic amines (HAs) formation, texture, colour and sensory properties. The results showed that 5 kinds of free and 9 kinds of protein‐bound heterocyclic amines were detected. The total amount of protein‐bound heterocyclic amines was much higher than that of the free state. Harman and Norharman, belonging to β‐carboline, constituted over 80% of the total content of heterocyclic amines. Considering the HAs formation and quality attributes, when the grilling condition was 280 °C for 10 min, the total content of HAs was the lowest, and the fish had moderate moisture content, firm texture, bright colour, and high sensory evaluation score.

Formation and prediction of heterocyclic amines and N-nitrosamines in smoked sausages using back propagation artificial neural network.

Heterocyclic amines (HAs) and N-nitrosamines (NAs) are formed easily during the thermal processing of food, and epidemiological studies have demonstrated that consuming HAs and NAs increases the risk of cancer. However, there are few studies on the application of back propagation artificial neural network (BP-ANN) models to simultaneously predict the content of HAs and NAs in sausages. This study aimed to investigate the effects of cooking time and temperature, smoking time and temperature, and fat-to-lean ratio on the formation of HAs and NAs in smoked sausages, and to predict their total content based on the BP-ANN model. With an increase in processing time, processing temperature and fat ratio, the content of HAs and NAs in smoked sausages increased significantly, while the content of HA precursors and nitrite residues decreased significantly. The optimal network topology of the BP-ANN model was 5-11-2, the correlation coefficient values for training, validation, testing and all datasets were 0.99228, 0.99785, 0.99520 and 0.99369, respectively, and the mean squared error value of the best validation performance was 0.11326. The bias factor and the accuracy factor were within acceptable limits, and the predicted values approximated the true values, indicating that the model has good predictive performance. The contents of HAs and NAs in smoked sausages were significantly influenced by the cooking conditions, smoking conditions and fat ratio. The BP-ANN model has high application value in predicting the contents of HAs and NAs in sausages, which provides a theoretical basis for the suppression of carcinogen formation. © 2024 Society of Chemical Industry.

Effects of Fingerroot (Boesenbergia pandurata) Oil on Microflora as an Antimicrobial Agent and on the Formation of Heterocyclic Amines in Fried Meatballs

This study aimed to determine the antibacterial activity of the essential oil of fingerroot (Boesenbergia pandurata) (EOF) as a natural preservative in ground meat and its effect on the formation of heterocyclic amines (HAs) in pan-fried meatballs. EOF was applied either by adding it to ground pork or marinating pork in it before grinding. In addition, the antibacterial activity of EOF was tested. Aerobic mesophilic total viable count (TVC), lactic acid bacteria (LAB), and Enterobacteriaceae bacteria were monitored. The results show that EOF exhibited strong antibacterial activity when added at concentrations of 1.0 and 2.5 wt%. Antimicrobial activity against TVC, LAB, and especially Enterobacteriaceae bacteria was observed at all EOF concentrations (0.25, 0.5, 1.0, and 2.5 wt%). A 2.5% concentration of EOF applied by marinating trimmings can extend the shelf-life of ground pork to 18 days, while 2.5% EOF applied via addition can extend the shelf-life to 15 days, compared with 3 days for the control sample. After frying the meatballs, the inhibitory effect on the formation of heterocyclic amines was only significant for MeIQx with the highest addition of EOF (2.5 wt%). Significant increases in the concentrations of all other HAs were determined by adding EOF (2.5 wt%).

Pre-regulation of the water content impacts on the flavor and harmful substances of sesame paste

In this study, the influence of pre-regulation of the water content (5–25 %) on the harmful substances and aroma compounds of sesame paste (SP) was investigated. The results indicated that pre-regulation of the water content reduced the generation of harmful substances in SP. Notably, the total heterocyclic amine content in SP-15 was significantly lower than in other samples. SP-10 had the lowest total polycyclic aromatic hydrocarbon content, while SP-5 exhibited the lowest PAH4 content. Using solvent-assisted aroma evaporation and GC-O-MS, 50 aroma compounds were identified in SP. Pre-regulation of water content in SP led to an elevated concentration of heterocyclic compounds thereby imparting a diverse aromatic profile. It enhanced the perceived intensity of roasted sesame and salty pastry aromas while reducing the perceived intensity of fermentation and burnt aromas. The findings suggested the pre-regulation of the water content played a crucial role in aroma modulation and harmful substances control in SP.

Comprehensive Analyses of Advanced Glycation end Products and Heterocyclic Amines in Peanuts during the Roasting Process.

Advanced glycation end products (AGEs) and heterocyclic amines (HAs) are two kinds of important harmful products formed simultaneously during the thermal processing of proteinaceous food. In this paper, the effect of roasting conditions on the formation of AGEs and HAs, as well as active carbonyl intermediates in common peanut (C-peanut) and high-oleic acid peanut (HO-peanut) was studied simultaneously for the first time. In general, with the increase in roasting temperature (160-200 °C) and time, the contents of AGEs, HAs and active carbonyl intermediates (i.e., glyoxal (GO) and methylglyoxal (MGO)) significantly increased in peanuts. Four kinds of HAs (i.e., AαC, DMIP, Harman and Norharman) were observed in roasted peanuts, of which Harman and Norharman accounted for about 93.0% of the total HAs content after roasting for 30 min at 200 °C. Furthermore, a correlation analysis among AGEs (i.e., Nε-(1-Carboxymethyl)-L-lysine (CML) and Nε-(1-Carboxyethyl)-L-lysine (CEL)), HAs, GO and MGO was conducted. Most of these compounds showed an excellent positive linear relationship (p ≤ 0.001) with each other. The evident increase in GO and MGO contents implied an increase in not only the content of AGEs but also HAs. However, contents of AGEs and HAs showed no significant difference between roasted HO-peanut and C-peanut. This study would provide a theoretical basis for simultaneously controlling the levels of AGEs and HAs in thermal processed peanut foods.

Inhibitory Effects of Some Hydrocolloids on the Formation of Advanced Glycation End Products and Heterocyclic Amines in Chemical Models and Grilled Beef Patties.

Effectively inhibiting the formation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) is crucial to human health. In the present study, chemical model systems were used to evaluate the inhibitory effects of seven hydrocolloids on HA and AGE formation. The results showed that hydrocolloids effectively inhibited the formation of two major AGEs. However, their inhibitory action against HA formation showed unexpected results, wherein alginic acid, carrageenan and konjac glucomannan promoted the formation of 2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), harmane, norharmane and 2-amino-3,8-dimethyl-imidazo [4,5-f]-quinoline (MeIQx). Only chitosan and pectin showed significant inhibitory effects on HAs, reducing HA levels by 34.5-56.3% and 30.1-56.6%, respectively. In grilled beef patties, the addition of 1.5% chitosan and pectin significantly decreased AGE and HA content by 53.8-67.0% and 46.9-68.1%, respectively. Moreover, it had a limited impact on quality and sensory properties. Further mechanism studies conducted in model systems revealed that chitosan and pectin decreased the formation of key intermediates of AGEs and HAs. These findings suggest that chitosan and pectin are powerful inhibitors against AGE and HA formation with minimal impact on food quality. Therefore, their application in meat preparation and processing could effectively decrease human dietary exposure to HAs and AGEs.

Effects of Oil and Processing Conditions on Formation of Heterocyclic Amines and Polycyclic Aromatic Hydrocarbons in Pork Fiber.

Toxic compounds such as heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs) can be produced during food processing, especially meat products. This study aims to monitor the formation of HAs and PAHs in fried pork fiber, a common meat product in Taiwan, at different processing conditions. A total of six experimental groups, including raw pork tenderloin, dried pork filaments, sesame oil-stir-fried pork at 160 °C for 15 min, sesame oil-stir-fried pork at 200 °C for 6 min, lard-stir-fried pork at 160 °C for 15 min, and lard-stir-fried pork at 200 °C for 6 min, were prepared and analyzed for formation of HAs via UPLC-MS/MS and PAHs via GC-MS/MS in triplicate. Frying in sesame oil or lard showed a greater content of total HAs in fried pork fiber processed at 160 °C for 15 min than at 200 °C for 6 min. However, in the same heating conditions, pork fiber fried in sesame oil produced a higher level of total HAs than that fried in lard. Of the various HAs in fried pork fiber, both Harman and Norharman were generated in the highest amount. The precursors, including reducing sugar, amino acid, and creatine/creatinine, played a vital role in HAs formation in fried pork fiber. For total PAHs, the highest level was shown for pork fiber fried in lard at 200 °C/6 min, followed by frying in sesame oil at 200 °C/6 min and 160 °C/15 min, and in lard at 160 °C/15 min. Like HAs, at the same heating condition, a greater content of total PAHs was produced in pork fiber fried in sesame oil than in lard. Notably, the highly toxic benzo[a]pyrene was undetected in fried pork fiber. The PAH precursor benzaldehyde was shown to generate at a much higher level than 2-cyclohexene-1-one and trans,trans-2,4-decadienal in fried pork fiber, and it should play a more important role in PAH formation. Principal component analysis (PCA) also revealed that the formation mechanism of HAs and PAHs in fried pork fiber was different.

Impact of seed-roasting treatment on polycyclic aromatic hydrocarbons, 3-MCPD esters, heterocyclic amines and volatile components formation in sunflower oil

Seed-roasting is a crucial process conducted to improve the organoleptic and conservative features of oilseeds. In this paper, raw sunflower seeds were roasted at 160, 180 and 200 °C for various times. Three hazards (polycyclic aromatic hydrocarbons, 3-monochloro-1,2-propanediol esters and heterocyclic amines) and volatile components in the corresponding oil extracted from roasted sunflower seeds were analyzed. Polycyclic aromatic hydrocarbons, 3-monochloro-1,2-propanediol esters and heterocyclic amines were measured using HPLC, GC-MS and UPLC-MS, respectively. Volatiles were determined by GC-MS. The results show that the strength of seed-roasting promoted the formation of the three hazard factors. The contents of polycyclic aromatic hydrocarbons, 3-monochloro-1,2-propanediol esters and heterocyclic amines in sunflower oil increased 9.4, 22.1 and 121.6 fold respectively after roasting at 200 °C for 25 min. The main volatiles were aldehydes and terpenes with a greenish and earthy taste. Volatile levels possessing pleasant flavors of floral, roasted and nuts, particularly aldehydes and pyrazines, generally increased with roasting. However, at high intensity roasting, the appearance of furans would bring burnt, bitter, as well as viscosity, resulting in poor sensory for oil. Considering the limitation of the above mentioned hazards established by EU, the optimal roasting condition of sunflower seed was 180–200 °C for 15–20 min.

The impact of temperature-controlled smoldering smoking on polycyclic aromatic hydrocarbons and heterocyclic amines contents in Frankfurter-type sausages

The impact of temperature-controlled smoldering smoking conditions on the accumulations of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HAs) in Frankfurter-type sausages was investigated. Depending on the temperature, smoking can be divided into two phases: an unstable pyrolysis stage (≈ 200 s) and a stable pyrolysis stage (>200 s), which had different effects on hazardous substances contents. The unstable pyrolysis stage, which contributed 66.9 ∼ 89.6% of PAH accumulations by comparing with sausages smoked for 15 min, has significant impact on high PAH residues. By contrast, the contents of HAs showed steady increase trends with smoking time. Few types of free-HAs with low concentrations (3.05 ∼ 22.9 ng/g DW), but more types of bound-HAs with much higher levels (10.8 ∼ 396 ng/g DW) were found. In addition, the formation of some HAs followed the first-order reaction model. However, the detailed formation mechanisms of PAHs and HAs under temperature-controlled smoldering smoking conditions remain to be studied.

The effects of different cooking methods and spices on the formation of 11 HCAs in chicken wing and pork belly

Heterocyclic amines (HCAs) are mutagenic and carcinogenic compounds formed when cooking meats, such as chicken and pork. In this study, the effect of different cooking methods (air frying, infrared cooker, pan frying, and electric oven) and spices (rosemary, turmeric, and garlic) on the formation of 11 HCAs (IQ, MelQ, MelQx, 4,8-DiMelQx, PhIP, AαC, MeAαC, Trp-P-1, Trp-P-2, Harman, and Norharman) in chicken wing and pork belly were determined by ultra-high-performance liquid chromatography−triple quadrupole mass spectrometry, and the physicochemical characteristics of the cooked meats were compared. The effect of air frying temperatures and times on the 11 HCAs formation was also investigated. Pan-fried chicken wing and pork belly lost less moisture and weight than the other samples. Air frying resulted in the lowest contents of 11 HCAs compared to pan frying, cooking in an electric oven, and infrared cooking, regardless of meat type. For example, 11 HCAs levels in air-fried chicken wings were 4.35 μg/kg, with the inhibition rate of 75.29% comparing with pan-fried chicken wings (17.61 μg/kg). HCAs formation depended on air frying temperatures and times. For example, the HCAs contents in chicken wing air-fried at 200 °C for 20 min (2.98 μg/kg) increased by 2.8 times compared to chicken wing air-fried at 140 °C for 50 min (1.08 μg/kg). Additionally, all spices showed an inhibitory effect on HCA formation. Especially, turmeric exhibited the highest inhibitory effect on the formation of HCAs by 50.67%. These results indicate that air frying and spices could inhibit the formation of HCAs during the thermal preparation of meats.

Effect of pomegranate peel extract on the reduction of heterocyclic amines and quality characteristics of mutton meatballs

Abstract Pomegranate peel extract (PPE), rich in phenolic compounds, is an undervalued byproduct derived from processing pomegranates. However, there are very few studies on the inhibitory effect of PPE on harmful substances during meat processing. This study was intended to investigate the influence of different concentrations of PPE (0.50%, 1%, and 1.50%) on the generation of heterocyclic amines (HCAs) and some quality attributes in mutton meatballs. All samples with the addition of PPE (0, 0.50%, 1%, and 1.50%) were fried for different lengths of time (2.5 min and 5 min) at 175±5 °C, and the contents of fourteen HCAs, color, thiobarbituric acid reactive substances, and carbonyl values of fried mutton meatballs were evaluated. The results showed that samples fried at 2.5 min had a low HCA content, and the HCA content enhanced significantly when the frying time was increased from 2.5 to 5 min (P<0.05). In comparison with the control group, PPE could significantly inhibit the generation of total HCAs in fried mutton meatballs (P<0.05), and the total HCAs content decreased with increasing PPE concentration. PPE significantly reduced carbonyl and TBARS values in fried mutton meatballs (P<0.05). Moreover, PPE resulted in a significant increase in a* and b* values as well as a decrease in L* values in fried mutton meatballs (P<0.05). In conclusion, PPE could inhibit the formation of HCAs and improve the quality of mutton meatballs, and could be considered as a natural inhibitor of HCAs in fried meat products.

Inhibiting Effects of Ginger and Rosemary on the Formation of Heterocyclic Amines, Polycyclic Aromatic Hydrocarbons, and Trans Fatty Acids in Fried Pork Balls

The preparation of fried meat products is prone to the formation of large amounts of heterocyclic amines (HCAs), polycyclic aromatic hydrocarbons (PAHs), and trans fatty acids (TFAs), which are potential risks to human health. Spices contain natural antioxidants that can inhibit the oxidation of fats and oils and the formation of hazardous substances. In this experiment, the effect of adding different levels (0.25%, 0.75%, 1.25%) of ginger or rosemary during meatball preparation on the formation of HCAs, PAHs and TFAs in fried pork balls was investigated. The results showed that the addition of ginger and rosemary reduced the content of HCAs in fried pork balls compared to the control group (no added spices). The inhibition of total HCAs was 63% when 0.25% ginger was added, while the total HCA content was reduced to 59% when 0.25% rosemary was added. The addition of 0.25% and 0.75% rosemary reduced the PAH content in fried pork balls by 30% and 35%. In addition, ginger and rosemary showed significant inhibition of C20:1 11t in TFAs, with a maximum inhibition rate of 40%. Therefore, adding appropriate levels of ginger or rosemary to fried pork balls could simultaneously inhibit the formation of HCAs, PAHs, and TFAs.

Effect of cold atmospheric plasma-assisted curing process on the color, odor, volatile composition, and heterocyclic amines in beef meat roasted by charcoal and superheated steam

The use of cold atmospheric plasma (CAP) is fast becoming an emerging curing technology in the meat industry. The aim of this study was to assess CAP-assisted curing of beef meat roasted by charcoal (CR) and superheated steam (SR) in terms of flavor quality and heterocyclic amines (HAs) using electronic nose, GC–MS and UPLC-MS-MS. The CAP-assisted curing increased redness value by 46% and 8% in SR and CR meat respectively. Although CAP-assisted curing had little influence on the odor profile of SR meat, it influenced the odor profile of CR meat. Lipid oxidation-derived off-flavors in CR meat were not significantly (P > 0.05) changed after CAP treatment. However, these off-flavors were significantly (P < 0.05) reduced in SR meat. In addition, CAP-assisted curing did not increase the HAs contents in SR meat. CAP-assisted curing of SR meat improved flavor and did not increase toxic risk of SR meat.

The Effects of Volatile Organic Compounds (VOCs) on the Formation of Heterocyclic Amines (HAs) in Meat Patties, under Different Smoking Temperatures and Durations.

In this study, UPLC-MS/MS was used to study the effects of smoking duration and temperature on the formation of heterocyclic amines (HAs) in smoke-processed meat patties. Four kinds of free HAs-including F-7,8-DiMeIQx; F-MeAαC; F-Harman and F-Norharman-and six kinds of protein-bound HAs-including B-AαC; B-7,8-DiMeIQx; B-Glu-p-1; B-MeAαC; B-Harman and B-Norharman-were detected and quantified. Among the free HAs, we observed a 23-fold content increase (p &lt; 0.05), from 0-4 h (at 0 h and 4 h they were 4.24 ng·g-1 and 98.33 ng·g-1, respectively), and the content of the free HAs decreased to 78.80 ng·g-1, at 5 h. At the same time, the free HAs content increased from 53.52 ng·g-1, at 50 °C, to 127.16 ng·g-1, at 60 °C, and then decreased continuously. The content of the free HAs was the highest at 60 °C. For the protein-bound HAs, their content was found to generally decrease with the increase in smoking duration and temperature. However, at 5 h, the content of protein-bound HAs slightly increased to 984.2 ng·g-1. Meanwhile, at 90 °C, it increased to 1643.53 ng·g-1. Additionally, a total of 16 volatile organic compounds (VOCs) were found in all of the meat samples, of which 10 VOCs (one acid, three aldehydes and seven phenols) were significantly related to the formation of free HAs. These findings showed that all the different types of HAs were produced under low-temperature processing, which provided scientific insights into the potential generation of HAs during meat smoking processes and could be used as a reference to minimize the risks of cancer related to the consumption of smoked meat products.

The impact of sous vide braising on the sensory characteristics and heterocyclic amines contents of braised chicken

Braising is the key process in braised chicken production. However, traditional braising also causes quality deterioration and heterocyclic amines (HAs) formation due to over-cooking. In this study, the impact of sous vide braising (SVB) on the sensory characteristics and HAs contents were investigated. The results indicated that SVB significantly enhanced the water content, reduced the cooking loss and impacted the water distribution, while only slightly affected the color and texture. Moreover, SVB faintly affected the volatile organic compounds (VOCs) composition. The differences mainly came from the contents of 1-pentanol, heptanal (monomer), octanal (monomer), n-nonanal (monomer), pentanal (dimer) and three unknown VOCs. While maintaining the traditional sensory qualities, SVB1 samples (75 °C 2 h) had lower total HAs content (4.50 ± 0.64 ng/g), which was 15.6% lower than control (5.33 ± 0.43 ng/g). However, the total HAs contents in SVB3 (65 °C 3 h, 7.61 ± 0.76 ng/g) and SVB4 (65 °C 4 h, 9.57 ± 0.74 ng/g) samples were significantly higher. The result indicated that even lower braising temperature is not conducive to HAs generation, SVB still cannot effectively reduce the HAs residual contents with the extending duration. Therefore, how to reduce the HAs residual contents in sauce braised meat products effectively remains to be studied.

Raw to charred: Changes of precursors and intermediates and their correlation with heterocyclic amines formation in grilled lamb

This work aimed to investigate the changes and correlations of precursors, intermediates and heterocyclic amines (HCAs) in lamb during charcoal grilling. 28 chemical compounds were detected by high-performance liquid chromatography and gas chromatography–mass spectrometry in grilled lamb from raw to charred. Results demonstrated the types and contents of HCAs were increased during grilling, of which 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) was dominant and accounted for 61% at the end of grilling (42 min). Glucose and creatine (P < 0.05) decreased with grilling time, creatinine (P < 0.05) and total free amino acid increased. The types and contents of four intermediates (formaldehyde, acetaldehyde, phenylacetaldehyde, 2,5-dimethylpyrazine) increased during grilling. Glucose, creatine, creatinine, ten free amino acids and four intermediates showed significant correlation to HCAs. Also, the ratios of four precursors were significantly correlated with HCAs (P < 0.05), besides creatine/glucose ratio. These results suggested that the time of charcoal grilling should not exceed 14 min at 145 °C in order to reduce the formation of harmful compounds in lamb meat.