PhIP Formation Research Articles

L-cysteine modulates the Maillard reaction: Impacts on PhIP and pyrazine formation.

L-Cysteine (L-Cys) serves as both an inhibitor of the carcinogen 1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and an enhancer of food flavor, supporting efforts to improve food safety and quality. Using a glucose/phenylalanine/creatinine model system, this study assessed the effects of varying L-Cys concentrations on PhIP inhibition and pyrazine flavor enhancement through UPLC-MS/MS and GC-MS analyses. The optimal PhIP reduction (82.8%-83.1%) was achieved with 20mg and 100mg of L-Cys, whereas the pyrazine enhancement peaked with 200mg and 100mg of L-Cys (50.54%-99.16% and 37.83%-98.82%, respectively). A partial least squares regression (PLS) model demonstrated strong predictive accuracy (R2c and R2p>0.73), providing a robust framework for regulating PhIP and pyrazine levels. This study offers a theoretical basis for advancing food safety and flavor quality, contributing to the development of safer and more enjoyable food products while addressing health and sustainability considerations.

Effect and mechanism of polyphenols containing m-dihydroxyl structure on 2-amino-1-methyl-6-phenylimidazole [4, 5-b] pyridine (PhIP) formation in chemical models and roast pork patties

2-amino-1-methyl-6-phenylimidazole [4, 5-b] pyridine (PhIP) is a prevalent heterocyclic amine (HAA) found in heated processed meat. This study investigated the inhibitory impact of eight different types of polyphenols containing m-dihydroxyl structure on PhIP formation through a chemical model system. The structure-activity relationship and potential sites of action of polyphenols containing m-dihydroxyl structure were also analyzed. Then, the mechanism of inhibiting PhIP formation by kaempferol, naringenin and quercetin was speculated by UPLC-MS. Results showed that 8 kinds of polyphenols containing m-dihydroxyl structure had significant (P < 0.05) inhibition on the formation of PhIP in the chemical model system in a dose-dependent manner. In addition, PhIP was most significantly inhibited by naringenin at the same concentration, followed by kaempferol and quercetin (83.27%, 80.81% and 79.26%, respectively). UPLC-MS results speculated that kaempferol, naringenin, and quercetin formed a new admixture via an electrophilic aromatic substitution reaction with the intermediate product phenylacetaldehyde, preventing the formation of PhIP.

Formation of MeIQx and PhIP in model matrices from amino acids, carbohydrates, and creatine

The understanding of the reaction of HAA formation in foods is a key for finding methods for reduction of their quantity. Currently, more and more experimental works are dedicated to the question of HAA formation in model matrices to establish the main precursors, intermediate products, catalysts and inhibitors in the reaction of their formation. It is believed that HAAs are formed in foods in the course of the Maillard reaction. Amino acids, carbohydrates and creatin(in)e are assigned to the main precursors in the reaction of their formation. In this work, therefore, investigations of experimental matrices were carried out. The experimental matrices consisted of amino acids (eight essential, glutamic acid and aspartic acid), carbohydrates (glucose, fructose, saccharose, lactose) and creatine. The performed investigations have shown that carbohydrates can behave differently (both as catalysts and inhibitors) in the reaction of HAA formation. Among all studied matrices, the highest quantity of PhIP was found in the samples with phenylalanine; its content varied in a range from 7,159.79 to 27,837.79 ng/g. Based on this result, it is reasonable to suggest that among all amino acids, phenylalanine is the main precursor in the reaction of PhIP formation. High concentrations of PhIP were also observed in the samples with tryptophan in a range from 1,791.19 to 4,891.36 ng/g. The results obtained show that the use of certain sources of carbohydrates upon thermal processing of meat can theoretically lead to a reduction in the quantity of formed HAA.

Inhibitory effects of cassiae semen extract on the formation of 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) in model system.

2-Amino-1-methyl-6-phenylimidazole [4,5-b] pyridine (PhIP), a heterocyclic amine (HAA), is found in meat products heated at high temperatures. However, PhIP is a mutagenic and potential carcinogenic compound. Cassiae semen, a type of medicine and food homology plant, is abundant in China and has been less applied for inhibiting heterocyclic amines. To investigate the inhibitory effect of cassiae semen extract on PhIP formation within a model system and elucidate the inhibitory mechanism, an ultrasonic-assisted method with 70% ethanol was used to obtain cassiae semen extract, which was added to a model system (0.6 mmol of phenylalanine: creatinine, 1:1). PhIP was analyzed by LC-MS to determine inhibitory effect. The byproducts of the system and the mechanism of PhIP inhibition were verified by adding the extract to a model mixture of phenylacetaldehyde, phenylacetaldehyde and creatinine. The results indicated that PhIP production decreased as the concentration of cassiae semen extract increased, and the highest inhibition rate was 91.9%. Byproduct (E), with a mass-charge ratio of m/z 199.9, was detected in the phenylalanine and creatinine model system but was not detected in the other systems. The cassiae semen extract may have reacted with phenylalanine to produce byproduct (E), which prevented the degradation of phenylalanine by the Strecker reaction to produce phenylacetaldehyde. Cassiae semen extract consumed phenylalanine, which is the precursor for PhIP, thus inhibiting the formation of phenylacetaldehyde and ultimately inhibiting PhIP formation. The main objective of this study was to elucidate the mechanism by which cassiae semen inhibit PhIP formation and establish a theoretical and scientific foundation for practical control measures.

Unraveling the relationships between processing conditions and PhIP formation in chemical model system and roast pork patty via principal component analysis

2-amino-1-methyl-6-phenylimidazole [4,5-b] pyridine (PhIP) is one of the higher levels of HAAs produced in protein foods during heating. The effects of heating temperature, time, and concentration of precursors on PhIP and related substances in the chemical model system and roast pork patty were studied using HPLC-Q-Orbitrap-HRMS and GC–MS. Results showed that the heating temperature, time, and concentration of four precursors significantly affected PhIP and its related substances (P < 0.05) in the chemical model system. Among them, PhIP production was greatest when heating at 200 min with 220 °C, and the concentrations of phenylalanine, creatinine, glucose, and creatine added were 10, 20, 20, and 20 mmol/L, respectively. Moreover, as the fat proportion of roast pork patties increased, PhIP and its intermediate-phenylacetaldehyde concentrations increased substantially (P < 0.05). PCA results showed that the samples of PhIP and related substances gradually dispersed as the temperature and time increased, and there were obvious effects among them.

Novel hydrocolloids synthesized by polyphenols grafted onto chitosan: A promising coating to inhibit PhIP formation during pan-frying of golden pompano fillets

Hydrocolloids synthesized by gallic acid (GA) and ferulic acid (FA) grafting onto chitosan (CS) were characterized, and their effects on PhIP formation in pan-fried golden pompano were investigated. Spectrograms including nuclear magnetic resonance, Fourier transform infrared spectroscopy and ultraviolet-visible confirmed that GA and FA were successfully grafted onto CS via covalent bonds, with grafting degree of 97.06 ± 2.56 mg GA/g and 93.56 ± 2.76 mg FA/g, respectively. The CS-g-GA and CS-g-FA exerted better solubility and antioxidant activities than CS. For the 8-min pan-fried golden pompano fillets, CS-g-GA and CS-g-FA (0.5 %, m/v) significantly reduced the PhIP formation by 61.71 % and 81.64 %, respectively. Chemical models revealed that CS-g-GA and CS-g-FA inhibited PhIP formation mainly by decreasing the phenylacetaldehyde contents from Maillard reaction and competing with creatinine to react with phenylacetaldehyde. Therefore, it was suggested that CS-g-phenolic acids emerge as novel coating for aquatic products during processing and inhibit heterocyclic amines generation.

Effect of Immersion Time of Chicken Breast in Potato Starch Coating Containing Lysine on PhIP Levels.

This study investigated the effect of immersion time of chicken breasts in potato starch (PS) coating containing amino acids (AAs) on the formation of 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) and to evaluate a possible mechanism to inhibit the formation of PhIP in chicken breasts during frying. The chicken breasts with standardized dimensions were dipped in the potato starch (PS) coating solution containing 0.25% w/v lysine (Lys) for different times (15 min, 30 min, 1 h, 3 h, and 6 h). After drying the coating on the chickens, samples were fried at 195 °C for 7.5 min on each side. Results showed that the immersion time does not significantly decrease (p < 0.05) the PhIP level, suggesting that 15 min immersion time is enough for PhIP reduction compared to the control chicken samples (without coating). Phenylacetaldehyde (PheAce) was increased in chicken breast coated with PS-0.25% Lys after frying, suggesting that there should be another pathway to prevent the formation of PhIP by the addition of PS-0.25% Lys. Volatile compound analysis also confirmed this and showed increases in many aroma compounds in the coated chicken. Moreover, no significant differences (p < 0.05) were shown between the cooking loss percentage, color parameters, texture profile, and tenderness of chicken with the PS-0.25% coating and chicken without coating.

Effect of potato starch coating containing selected amino acids to prevent the formation of PhIP in pan-fried chicken breast.

The effects of potato starch (PS) coating containing amino acids (AAs) on the formation of 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) in chicken breasts were evaluated. PhIP is classified as a Group 2B carcinogen by the International Agency for Research on Cancer (IARC). The 5% (w/w) gelatinized PS coating solution was incorporated with tryptophan (Trp) or lysine (Lys) at 0.25%, 0.5%, and 0.75% (w/w of the coating solution) concentrations. Chicken breast cuts with the same dimensions (5×2×1.5cm) were dipped in the PS coating solution for 15min before frying. After frying the chicken at 195°C for 7.5min on each side, PhIP levels, color, cooking loss, tenderness, and texture profile assay were evaluated. The average PhIP concentration was decreased from 92.62ng/g for the control chicken breast without coating to 6.30ng/g (0.25% Lys), 6.76ng/g (0.5% Lys), and 11.98ng/g (0.75% Lys), accounting for an 89%-92% reduction in PhIP levels compared to the controls. However, dipping in Trp-containing PS coating had a significantly lower (p<0.05) PhIP reduction effect (34%-67%). There was no significant difference in cooking loss percentage, tenderness, texture profile parameters, and color parameters of PS-coated chicken. Triangle test results showed that consumers did not detect a significant difference in the PS-coated chicken breasts (p<0.001). Overall, this study suggests that the application of PS-based coatings incorporated with AAs on chicken breast reduces the PhIP formation.

Inhibitory effects of hydrocolloids on the formation of heterocyclic aromatic amines in smoked chicken drumsticks and the underlying mechanism

This study aims to investigate the inhibitory effects of hydrocolloids on heterocyclic aromatic amine (HAA) formation in chemical model systems and smoked chicken drumsticks. In chemical model systems I and II, xanthan gum (XG) and carboxymethyl cellulose sodium (CMC-Na) effectively inhibited the 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) formation in comparison with the control sample ( P < 0.05). Arabic gum (AG) inhibited the PhIP and Harman formation ( P < 0.05), but its inhibitory action against Norharman formation was not significant ( P > 0.05). Further mechanism investigation of chemical model system I showed that the formation of PhIP was mainly inhibited via trapping phenylalanine and creatinine by glyoxal and methyglyoxal. A mechanistic investigation of chemical model system II suggested the inhibition of Harman and Norharman formation by XG and CMC-Na could be through trapping tryptophan by glyoxal and methyglyoxal. In smoked chicken drumsticks, CMC-Na had a dose-dependent inhibitory effect against the PhIP, Harman, and Norharman formation in comparison with the control sample ( P < 0.05), and 2.0% CMC-Na had the highest inhibitory rates of 45.83%, 21.82%, and 30.92%, respectively. Moreover, CMC-Na effectively inhibited the formation of PhIP, Harman, and Norharman precursors and intermediates in smoked chicken drumsticks, which further confirmed the above inhibition mechanism of CMC-Na. These results could provide an effective approach to reduce HAA formation in smoked meat products by incorporating hydrocolloids. • XG and CMC-Na inhibit PhIP, Harman, and Norharman formation in chemical model system. • AG inhibit the formation of PhIP and Harman in chemical model system. • 2.0% CMC-Na is the most promising inhibitor of HAAs in smoked chicken drumsticks. • Hydrocolloids can inhibit HAAs by trapping their precursors and intermediates.

Perilla frutescens seed meal as a fat substitute mitigates heterocyclic amine formation and protein oxidation and improves fatty acid profile of pan-fried chicken patties.

Fatty acid profile, protein and fatty acid oxidation and flavor profile of pan-fried chicken patties formulated with various levels of Perilla frutescens seed meal (PSM) as a fat substitute was investigated in this study. The formation of heterocyclic amines (HCAs) in the chicken patties was also evaluated. The results showed that pan-fried patties formulated with 20% PSM (PSM4) had the highest ranges of oleic acid and ΣMUFA content and ΣPUFA/ΣSFA ratio. Low to medium levels of PSM (PSM1, 2, and 3 corresponding to 5, 10, and 15% of PSM, respectively) reduced the content of lipid peroxidation products, while high level (PSM4) increased it. All levels of PSM were also found to be effective against elevation in carbonyl content relative to the control. Moreover, the PSM effectively inhibited HCA formation in the chicken patties. The total contents of HCAs in PSM1, PSM2, PSM3, and PSM4 samples were significantly (P < 0.05) lower than that of the control sample, corresponding to 31.9, 46.1, 57.2, and 44.8% inhibition, respectively. PSM4, however, had no or very little effect on the formation of PhIP, 4,8-DiMeIQx and AαC, despite a strong inhibitory effect on MeIQx formation. These findings not only support the promising potential of PSM for application as a fat substitute to improve the fatty acid profile and reduce the content of harmful by-products in heat-processed chicken, but also highlight that appropriate addition level is a critical factor in optimizing the functional capacity of this natural agent.

Synergistic Inhibitory Effects of Selected Amino Acids on the Formation of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in both Benzaldehyde- and Phenylacetaldehyde-Creatinine Model Systems.

Although various inhibitors have been employed to react with phenylacetaldehyde to form adducts and thus interrupt the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), high concentrations of PhIP remain in the final system. It remains unknown whether other critical aldehyde or ketone intermediates are involved in the generation of PhIP, and scavenging these reactive carbonyls simultaneously may achieve higher inhibitory efficiency of PhIP. In this study, reactive carbonyls in a glucose/creatinine/phenylalanine model system were first identified by gas chromatography-mass spectrometry (GC-MS), and then the single and synergistic effects of nonprecursor amino acids (cysteine, methionine, proline, histidine, arginine, and leucine) on scavenging reactive carbonyls were investigated to find out promising combination partners. The obtained results showed that the concentrations of benzaldehyde and phenylacetaldehyde in the glucose/creatinine/phenylalanine model system reached 0.49 ± 0.01 and 6.22 ± 0.21 μg/mL, respectively. Heating these carbonyl compounds in the presence of creatinine resulted in the quantity of PhIP produced increasing linearly with the added quantity of benzaldehyde (r = 0.9733, P = 0.0002) and phenylacetaldehyde (r = 0.9746, P = 0.0002), indicating that both compounds are key intermediates for PhIP generation. Among the investigated amino acids, histidine produced the maximum inhibition of PhIP formation (78-99%) in the benzaldehyde/creatinine model system, and proline produced the maximum inhibition of PhIP formation (13-97%) in the phenylacetaldehyde/creatinine model system, where both compounds decreased PhIP formation in a dose-dependent manner. Histidine in combination with proline enhanced the inhibitory effect against PhIP formation at a low addition level, where the highest inhibitory efficiency was obtained using a 1:3 mass ratio of histidine to proline (2 mg/mL in total), reducing PhIP formation by 96%. These findings suggest that histidine-proline combinations can scavenge benzaldehyde and phenylacetaldehyde simultaneously, enhancing the suppression of PhIP formation.

Cyanidin and rutin inhibit the formation of heterocyclic aromatic amines in chemical modeling systems and smoked chicken drumsticks

This study aims to evaluate the heterocyclic aromatic amine (HAA) formation inhibited by cyanidin and rutin in chemical modeling systems and smoked chicken drumsticks. In the PhIP and β-carboline chemical modeling systems, cyanidin inhibited the PhIP, Harman, and Norharman formation while rutin inhibited the PhIP formation but promoted the Harman and Norharman formation compared with control sample (P < 0.05). A mechanistic investigation confirmed that inhibiting the PhIP formation by cyanidin was mainly through trapping phenylalanine, creatine, creatinine, glucose, phenylacetaldehyde, and an aldol condensation product. In the smoked chicken drumsticks, cyanidin inhibited the PhIP, Harman, and Norharman formation dose-dependently compared to the control sample (P < 0.05), with 2.0 % (w/v) cyanidin having the highest inhibitory effect. Moreover, cyanidin inhibited the formation of PhIP precursors and intermediates in the smoked chicken drumsticks. These results provide evidence for using phenolic compounds to reduce HAA formation in smoked meat products.

Changes in flavor, heterocyclic aromatic amines, and quality characteristics of roasted chicken drumsticks at different processing stages

This study evaluated changes in flavor, heterocyclic aromatic amines (HAAs), and quality characteristics of roasted chicken drumsticks at three different processing stages: marinating (MS), low-temperature roasting (LRS), and high-temperature roasting (HRS). Raw chicken drumsticks (RC) served as the control. Water content and L*-value were significantly highest (P < 0.05), whereas a*-value and b*-value were significantly lowest (P < 0.05) in the HRS sample. Furthermore, the HRS sample had a significantly higher (P < 0.05) pH value than the RC, MS, and LRS samples. A total of 48 different volatile compounds were detected and electronic nose results indicated similar odor profiles between the MS and LRS samples. The LRS and HRS samples had significantly higher (P < 0.05) contents of PhIP, Harman, and Norharman than the RC and MS samples, which can be explained by the higher contents of precursors phenylalanine, tryptophan, and creatinine in the LRS and HRS samples compared to those in the RC and MS samples. Correlation analysis result indicated that the aldehydes and ketones are responsible for the PhIP, Harman, and Norharman formation. These results provide guidance for revealing the flavor and HAA formation of roasted chicken during processing.

Effect of acrolein, a lipid oxidation product, on the formation of the heterocyclic aromatic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in model systems and roasted tilapia fish patties.

The effect of acrolein on the formation of the 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was investigated in a chemical model. Acrolein was found to increase PhIP formation at each tested addition level. 0-0.2mmol of acrolein increased PhIP formation dose-dependently, while high levels of acrolein (>0.2mmol) did not further increase PhIP formation. Mechanistic study showed that acrolein addition decreased the residue of phenylalanine and creatinine, but increased the content of some key intermediates. Further analysis indicated that acrolein can react with phenylalanine, creatinine, and PhIP to form adducts. These results suggested that acrolein was able to contribute to PhIP formation as a consequence of its comprehensive ability to facilitate Strecker degradation of phenylalanine and react with phenylalanine, creatinine, and PhIP. In addition, oxidation of the tilapia fish increased the PhIP formation in the roasted fish patties, further supporting the potential contribution role of lipid oxidation products to the formation of PhIP.

Chitosan and flavonoid glycosides are promising combination partners for enhanced inhibition of heterocyclic amine formation in roast beef

The effects of different kinds of chitosan, oligomer (ChiO) and monomer (Gluco), and the combinations of polymer (Chi) or ChiO with flavonoid aglycones and glycosides against the formation of major HAs were investigated to find out potential combination partners for enhanced suppression of HA formation. Results in roast beef patties showed ChiO and Gluco significantly inhibited PhIP and MeIQx formation by 43–80% and 31–57%, respectively. Of which, ChiO was the most effective. In combinations with flavonoid glycosides (phloridzin, rutin and hesperidzin, respectively), Chi, but not ChiO, generated enhanced inhibitory effects. Further analysis showed Chi and phloridzin combined at a ratio of 1:1 was the most promising, especially in inhibiting PhIP, and the mechanism behind involved: 1) water retention by Chi, and 2) reduction of phenylalanine availability by phloridzin. These findings suggest that appropriate combination of Chi and flavonoid glycosides contributes to significant improvement in the safety of meat products.

Formation and Prediction of PhIP, Harman, and Norharman in Chemical Model Systems Containing Epicatechin under Various Reaction Conditions.

The aim of this study was to investigate the formation rules of 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) in chemical model systems containing epicatechin under various reaction conditions and establish their prediction models. The results indicated that at 100-200 °C and pH 5.5-7.5 for 10-90 min, epicatechin inhibited the formation of PhIP, Harman, and Norharman by 32-100, 1-93, and 5-98%, respectively. The exponential growth equation in the growth model with R2 of 0.986-0.997, the second-order equation in the polynomial model with R2 of 0.900-0.949, and the trigonometric function equation in the Fourier model with R2 of 0.513-0.926 were well fitted for the formation of PhIP, Harman, and Norharman at various temperatures, times, and pHs, respectively. The calibration set (R2c) and the prediction set (R2p) of the optimal partial least squares regression prediction model was 0.74 and 0.70 for PhIP, 0.75 and 0.70 for Harman, and 0.90 and 0.91 for Norharman, respectively. The results provide theoretical support to develop technologies or equipment for the real-time synchronous monitoring of PhIP, Harman, and Norharman during meat processing.

Effects of the Deacetylation Degree of Chitosan on 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) Formation in Chemical Models and Beef Patties

The effects of the deacetylation degree (DD) of chitosan on heterocyclic aromatic amine formation were investigated in chemical models and beef patties. The results in model systems showed that at lower addition levels (10 mg), chitosan with 85% DD showed the strongest inhibitory effect against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formation, while chitosan with a higher DD (95%) or a lower DD (72 and 50%) did not show any significantly inhibitory effect. Further mechanism study showed that chitosan addition reduced the content of Maillard reaction intermediates including phenylacetaldehyde and the aldol condensation product but increased the PhIP precursor creatinine residue in the chemical model, indicating that chitosan at least partially competed with creatinine to react with phenylacetaldehyde to inhibit PhIP formation. In roast beef patties, 0.15% (w/w) chitosan (85% DD) significantly reduced the formation of PhIP, MeIQx, 4,8-DiMeIQx, Harman, and Norharman by 56.21, 33.32, 31.35, 25.14, and 28.12%, respectively. Moreover, chitosan significantly inhibited the formation of aldehydes in roast beef patties, further confirming the above-mentioned inhibition mechanism. However, the addition of chitosan might promote fatty acid oxidation. In addition, chitosan addition below 0.15% (w/w) had no significant effect on the textural properties of the roast samples.

The inhibitory effects of yellow mustard (Brassica juncea) and its characteristic pungent ingredient allyl isothiocyanate (AITC) on PhIP formation: Focused on the inhibitory pathways of AITC

The effects of yellow mustard (Brassica juncea) and its characteristic component allyl isothiocyanate (AITC) on the formation of 2-amino-y1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP) in roast beef patties and PhIP-producing model systems were investigated. The probable inhibitory pathways of AITC on PhIP formation were also investigated in the model systems. The results revealed that yellow mustard and AITC can reduce PhIP in roast beef patties up to 41.7% and 60.2%, respectively. The rate of inhibition of PhIP also reached 64.8% in the PhIP-producing model systems. Furthermore, AITC could react with creatinine and phenylalanine in the model system (reducing each by 15.0%%–23.7% and 31.4%–55.8%, respectively). AITC showed the great scavenging ability of free radical scavenging (up to 64.2%). AITC also reacted with the intermediate phenylacetaldehyde (16.9%–30.8%) and the final product PhIP (7.0%–24.6%). It is speculated that AITC can inhibit PhIP through competitive inhibition of precursors, blocking intermediate, free radical scavenging, and direct elimination of PhIP.

Inhibitory effects of hyperoside and quercitrin from Zanthoxylum bungeanum Maxim. leaf on 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine formation by trapping phenylacetaldehyde

2-amino-1-methyl-6-phenylimidazole[4,5-b]pyridine (PhIP) is one of the most abundant Heterocyclic amines (HAs) in meat products. Zanthoxylum bungeanum Maxim. leaf (ZML) extract has been shown to be rich in polyphenols, which are gaining increasing interest as efficient tools for inhibiting the formation of HAs. In the present work, the effects of ZML extract, major polyphenols, chlorogenic acid, hyperoside and quercitrin on the formation of PhIP in both roast beef patties and chemical model systems were investigated. UPLC-MS showed that ZML extract and those three polyphenols effectively inhibited PhIP formation. Additionally, GC-MS analysis showed that those three polyphenols significantly reduced the content of phenylacetaldehyde in the model systems, a key intermediate involved in PhIP formation. The subsequent UPLC-MS and TOF-MS/MS analysis found that hyperoside and quercitrin reacted with phenyacetaldehyde to form those four adducts, 8-C-(E-Phenylethenyl)hyperoside, 6-C-(E-Phenylethenyl)hyperoside, 8-C-(E-Phenylethenyl)quercitrin and 6-C-(E-Phenylethenyl)quercitrin, respectively. The results revealed that hyperoside and quercitrin could trap phenylacetaldehyde to form adducts, thereby, retarding the reaction of phenylacetaldehyde and creatinine, blocking the generation of PhIP.

Chlorogenic acid and Epicatechin: An efficient inhibitor of heterocyclic amines in charcoal roasted lamb meats

There are few studies on controlling the formation of heterocyclic amines (HAs) by adding polyphenols to roasted lamb. The aim of this study was to assess the inhibitory effect of 0.025, 0.125, and 0.625 mmol of chlorogenic acid, epicatechin, rutin, quercetin and quinic acid on the formation of HAs in charcoal roasted lamb, respectively, by UHPLC-MS/MS. The results indicated that Harman, Norharman, PhIP, IQx and 8-MeIQx were detected, but both chlorogenic acid and epicatechin greatly inhibited the formation of IQx, 8-MeIQx, Norharman, Harman and PhIP, and epicatechin had better inhibitory effect than chlorogenic acid. PLSR-VID analysis suggested the key precursors of HAs formation in roasted lamb were glucose, ribose, fructose, isoleucine, valine, and lysine. In addition, this work also implied that the potential mechanism of inhibition of HAs formation by chlorogenic acid and epicatechin in roasted lamb might attribute to competitive chemical reactions between polyphenols and key precursors of HAs.