Journal of Hazardous Materials 268 (2014) 1–5
Contents lists available at ScienceDirect
Journal of Hazardous Materials journal homepage: www.elsevier.com/locate/jhazmat
Research Article
Chlorogenic acid increased acrylamide formation through promotion of HMF formation and 3-aminopropionamide deamination Yun Cai a,1 , Zhenhua Zhang a,1 , Shanshan Jiang a,1 , Miao Yu a , Caihuan Huang a , Ruixia Qiu a , Yueyu Zou a , Qirui Zhang a , Shiyi Ou a,∗ , Hua Zhou a , Yong Wang a , Weibing Bai a , Yiqun Li b a b
Department of Food Science and Engineering, Jinan University, Guangzhou 510632, China Department of Chemistry, Jinan University, Guangzhou 510632, China
h i g h l i g h t s
g r a p h i c a l
a b s t r a c t
• Chlorogenic
acid increased the formation of acrylamide while its quinone one inhibited. • Chlorogenic acid increased acrylamide formation by enhancing HMF production. • It decreased the activation energy for conversion of 3-APA to acrylamide. • It kept high redox potential that may inhibited acrylamide elimination.
a r t i c l e
i n f o
Article history: Received 18 October 2013 Received in revised form 29 December 2013 Accepted 30 December 2013 Available online 7 January 2014 Keywords: Chlorogenic acid Acrylamide HMF 3-Aminopropionamide
a b s t r a c t This research was aimed to investigate why chlorogenic acid, presents at high concentrations in some food raw material, influences acrylamide formation. In the asparagine/glucose Maillard reaction system (pH = 6.8), addition of chlorogenic acid significantly increased acrylamide formation and inhibited its elimination. In contrast, the quinone derivative of chlorogenic acid decreased acrylamide formation. Three mechanisms may be involved for increasing acrylamide formation by chlorogenic acid. Firstly, it increased the formation of HMF, which acts as a more efficient precursor than glucose to form acrylamide. Secondly, it decreased activation energy for conversion of 3-aminopropionamide (3-APA) to acrylamide (from 173.2 to 136.6 kJ/mol), and enhances deamination from 3-APA. And thirdly, it prevented attack of the produced acrylamide from free radicals by keeping high redox potential during the Maillard reaction.
1. Introduction Acrylamide is a food contaminant formed mainly through Maillard reaction during high-temperature processing. It has neurotoxic
Abbreviations: 3-APA, 3-aminopropionamide; Asn, asparagine; CA, chlorogenic acid; Ea, activation energy; Glu, glucose; HMF, hydroxymethylfurfural; ORP, oxidation–reduction potential; PBS, phosphate buffer solution; PPO, polyphenol oxidase. ∗ Corresponding author. Tel.: +86 2085224235; fax: +86 2085226630. E-mail addresses: [email protected], [email protected] (S. Ou). 1 Contributed equally to this work. 0304-3894/$ – see front matter © 2014 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jhazmat.2013.12.067
© 2014 Elsevier B.V. All rights reserved.
and genotoxic properties, and is known to act as a carcinogen in rodents [1]. The contents of acrylamide vary among different types of food. Fried potato chips, coffee and toasted chicory contain much higher levels of acrylamide than other high temperature-processed foods [1,2], with the highest reported concentrations of 12,000, 539, and 4015 g/kg, respectively [3–5]. Food ingredients play an important role in acrylamide formation. A considerable number of antioxidants, including vitamin C, vitamin E, ferulic acid, tert-butylhydroquinone, butylated hydroxyanisole, butylated hydroxytoluene, epigallocatechin gallate, sodium erythorbate, antioxidants from bamboo leaves, tea polyphenols, and spice extracts have all been reported to influence acrylamide formation [6–11]. However, reports on relationships
2
Y. Cai et al. / Journal of Hazardous Materials 268 (2014) 1–5
between antioxidants and acrylamide contents in food have been controversial [11]. Coffee beans and potato tubers contain high concentrations of chlorogenic acid (41,640 and 1481 mg/kg, respectively) [12,13], which can be oxidized to quinone by polyphenol oxidase during processing steps such as peeling and cutting [14]. It was reported that addition of chlorogenic acid at low level (30 mol/100 g) or at very high level (1 mmol/ml) decreased acrylamide formation both in biscuits and and asparagine/glucose reaction model [15,16]. However, the mechanisms underlying this effect remain to be investigated. In the present study, we investigated the effects of chlorogenic acid at moderate concentration (50 mol/ml) and its quinone derivative (prepared using polyphenol oxidase instead of hydrogen peroxide as we previously reported) [17], on the formation of acrylamide during high-temperature processing, focusing on the mechanism by which it promotes deamination of 3-APA and HMF formation. 2. Experimental 2.1. Chemicals Chlorogenic acid, HMF, asparagine, and glucose were purchased from Aladdin Reagents Database Inc. (Shanghai, China). Acrylamide standard (>99.8%) and 13 C3 -labeled acrylamide (99%) were obtained from Sigma-Aldrich Company (St. Louis, MO, USA) and Merck-Schuchardt (Hohenbrunn, Germany), respectively. 3-Aminopropionamide hydrochloride (-alaninamide hydrochloride, 3-APA) was purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). High-performance liquid chromatography (HPLC)grade methanol and polyphenol oxidase (845 U/mg) were obtained from J. T. Baker (USA) and Worthington Biochemical Corporation (Lakewood, NJ, USA), respectively. 2.2. Effects of chlorogenic acid and its quinone derivative on acrylamide formation An equimolar asparagine/glucose Maillard reaction system was used to investigate the effects of chlorogenic acid on acrylamide formation. Each 20-ml stainless-steel test tube contained 4 ml of 0.1 M phosphate buffer solution (PBS, pH = 6.8) with different concentrations of chlorogenic acid (both phenol and quinone type, at addition levels of 0.002, 0.02, and 0.2 mmol, respectively), 1 mmol asparagine and 1 mmol glucose. The test tubes were capped with Teflon pad-filled stainless steel cap and the mixtures were heated at 160 ◦ C in an oil bath installed with a magnetic stirrer for 20 min. After cooling, the reaction mixtures were decanted into 14-ml centrifuge tubes and deionized water was added to make a total volume of 10 ml in each tube. The mixtures were then centrifuged at 4000 rpm for 20 min on an Allegra 21 R centrifuge (Beckman, USA). Concentrations of acrylamide and HMF in the supernatant were then determined. The quinone derivative of chlorogenic acid was prepared using polyphenol oxidase. Chlorogenic acid (5 mmol) and 100 mg of polyphenol oxidase were successively dissolved in 100 ml of 0.1 M PBS (pH = 6.8), and the reaction mixture was then placed in a 250-ml Erlenmeyer flask and incubated at 25 ◦ C for 60 min with shaking at 150 rpm. After the reaction was completed, polyphenol oxidase was removed using a Pellicon® XL 50 cassette and a Labscale TFF system. HPLC analysis showed that all chlorogenic acid was transformed to its quinone derivative. 2.3. Effect of chlorogenic acid or its quinone derivative on acrylamide formation during Maillard reaction A total of 4 ml of chlorogenic acid or its quinone derivative (50 mol/ml, dissolved in 0.1 M PBS, pH = 6.8) were mixed with
1 mmol of asparagine and 1 mmol of glucose in a 20-ml stainlesssteel test tube. The mixtures were heated at 160 ◦ C for 5, 10, 15, or 20 min. The amount of acrylamide formed under these conditions was then determined. Two reaction models, 1 mmol of asparagine reacted with 1 mmol of glucose or HMF without addition of chlorogenic acid in 4 ml PBS, were as the controls.
2.4. Effect of chlorogenic acid acrylamide elimination An equimolar asparagine/glucose (1 mmol) model reaction system containing 200 g of 13 C3 -labeled acrylamide and 0.2 mmol of chlorogenic acid or its quinone derivative in 0.1 M PBS (pH = 6.8) was used to assess the effect of chlorogenic acid on the elimination of acrylamide during the reaction process. The same system containing no chlorogenic acid or its quinone derivative was used as control.
2.5. Effect of chlorogenic acid on oxidation–reduction potential in the Maillard reaction system Oxidation–reduction potential of the supernatant of the Maillard reaction system described above was determined in the presence or absence of 0.2 mmol of chlorogenic acid at different reaction times using an ORP-422 model oxidation–reduction potential detector (Beijing Zhongxi Yuanda Scientific Instrument Co., Ltd., Beijing, China).
2.6. Effect of chlorogenic acid on acrylamide formation from 3-aminopropionamide (3-APA) pH value of 2.5 mM 3-APA solution was adjusted to 3.0, 4.0, 5.0, 6.0, or 7.0 using 0.1 M NaOH. Each solution (4 ml) was placed in a stainless-steel test tube and heated in an oil bath at 160 ◦ C for 15 min. The amounts of acrylamide produced under these conditions were then determined. Based on results obtained from the effect of pH, 2 ml of 5.0 mM 3-APA (dissolved in 0.1 M PBS, pH = 6.8) and 2 ml of chlorogenic acid or its quinone derivative (0.1 mmol/ml dissolved in 2 ml of 0.1 M PBS, pH = 6.8) were mixed, placed in a stainless-steel test tube and heated in an oil bath at 160 ◦ C for 5, 10, 15, and 20 min. The amounts of acrylamide produced were then determined.
2.7. Activation energies for the formation of acrylamide from 3-APA A solution (4 ml) containing 10 mol of 3-APA and 0.2 mmol of chlorogenic acid (in 0.1 M PBS buffer, pH = 6.8) was heated in an oil bath at 120, 130, 140, 150, 160, and 170 ◦ C for 5, 10, and 15 min, respectively. Activation energy for the conversion of 3-APA to acrylamide under each specific condition was determined as follows. Rate constant at a specific reaction temperature was obtained from the slope of a linear plot of the amount of acrylamide produced against reaction time. The effect of temperature on reaction rate constant k was expressed by the Arrhenius equation [18,19]: ln k = ln A −
Ea RT
where R is universal gas constant (8.314 J/K mol), T is temperature, k is reaction rate constant, Ea is activation energy, and A is frequency factor. A plot of (−ln K) versus 1/T yields a straight line with a slope of Ea /R.
Y. Cai et al. / Journal of Hazardous Materials 268 (2014) 1–5
3
Table 1 Effect of chlorogenic acid on acrylamide formation in the asparagine/glucose Maillard reaction system after heating at 160 ◦ C for 15 min (pH = 6.8). CA added (mol/ml)
Acrylamide (g/ml) HMF (g/ml) a
0
59.3 ± 3.2a 45.6 ± 3.6
0.5
5
50
No PPO treated
PPO treated
No PPO treated
PPO treated
No PPO treated
PPO treated
62.8 ± 2.7 56.3 ± 3.2
43.7 ± 3.3 44.7 ± 3.1
68.3 ± 6.7 75.7 ± 2.9
31.5 ± 2.8 39.2 ± 2.9
79.8 ± 5.4 83.5 ± 3.6
26.7 ± 3.2 37.7 ± 2.5
Means ± SD (n = 3).
2.8. Acrylamide analysis Acrylamide determination was performed as described previously [20]. Samples (4.8 ml each) were mixed with 0.2 ml of 13 C -labeled acrylamide internal standard (2 g/ml) and subjected 3 to liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS) analysis on a Shimadzu LC-20AT system (Shimadzu, Kyoto, Japan) equipped with an LC-10ATvp pump, a SIL-HTa autosampler, and a CTO-10Asvp temperature-controlled column oven, which was coupled to an API3000 MS detector with an atmospheric pressure chemical ionization interface. Samples (20 l) were eluted on a YMC-Pack ODS-AQ C18 column (150 mm × 4.6 mm, 5 m) at 40 ◦ C with an isocratic mixture of 0.5% methanol/0.1% acetic acid in deionized water at a flow rate of 0.5 ml/min. MS/MS was performed in positive ESI mode. Transitions m/z 72 → 55 and 75 → 58 were used in identification and quantification of acrylamide and 13 C3 -labeled acrylamide, respectively. 2.9. HMF analysis HMF determination was performed according to the method described by Chen et al. [19] with some modifications. Samples were filtered through a 0.45 m membrane and analyzed on a Shimadzu LC-20AT system (Shimadzu, Kyoto, Japan) equipped with a Zorbax SB-Aq column (4.6 mm × 250 mm, 5 m) (Agilent Technologies Co., Ltd., USA), a diode array detector, and LC-solution software. Samples (5 l each) were eluted with 5% methanol in water at a flow rate of 0.5 ml/min under isocratic conditions at 40 ◦ C. HMF was detected by absorbance at 284 nm and quantified using a standard curve generated with HMF standard solutions. 2.10. Analysis of 3-APA 3-APA was determined according to the method described by Gökmen et al. [21]. Samples were analyzed on an Acquity UPLCQuattro Premier XE (Waters, USA) coupled to an Agilent 6130 MS detector, which was equipped with an electrospray ionization (ESI) interface and MassLynx V4.1 data analysis software. Samples (5 l each) were separated on a Waters Acquity UPLC BEH C8 column (1.0 × 50 mm, 1.7 m) using an isocratic mixture of methanol:10 mM formic acid (70:30, v/v) as the mobile phase at a flow rate of 0.4 ml/min at 40 ◦ C. The MS detector was operated in positive ionization mode at drying gas (N2 ) flow rate of 800 l/h and capillary voltage of 0.5 kV. Signal response of the precursor ion [M + H]+ with m/z of 89 was used for quantification of 3-APA. Concentrations of 3-APA were calculated using a standard curve (y = 933.01x + 8642.2, R2 = 0. 9995) generated with 3-APA standard solutions of 10–100 ng/ml. 2.11. Determination of products formed by co-heating 3-APA with chlorogenic acid Samples (10 l each) were analyzed on a liquid chromatography–mass spectroscopy (LC–MS) system composed of a 4000Q–TRAP mass spectrometer (Applied Biosystem Sciex) and a Agilent–1100 HPLC system equipped with an Angilent
AORABAX Bonus RP column (2.1 mm × 150 mm, 5 m). Samples were eluted with pure water at a flow rate of 0.3 ml/min under isocratic conditions at 40 ◦ C. Full scan MS was conducted using ESI with selected ion recording. ESI positive or negative ions (±H+ ) were used to determine the molecular weight of product components and identify amino acid and acrylamide adducts. The newly formed nitrogen compounds were determined using an Agilent 6210 LC/TOF-MS with an Agilent Zorbax SB-C18 column (2.1 mm × 30 mm, 3.5 m). The TOF-MS operation parameters were as follows: drying gas (N2 ) at 9 l/min flow rate; drying gas temperature, 300 ◦ C; nebulising gas (N2 ) pressure, 30 psi; capillary voltage, 3500 V; skimmer voltage, 65 V and fragmentor voltage, 300 V. Elution was performed at a flow rate of 0.4 ml/min under isocratic conditions and using 10% methanol aqueous solution as the mobile phase. TOF-MS scanning results were collected as centroids from m/z 100 to 500. Two reference mass compounds, a lock mass solution including purine (C5 H4 N4 at m/z 121.050873) and hexakis (1H,1H,3H-tetrafluoropentoxy)phosphazene (C18 H18 O6 N3 P3 F24 at m/z 922.009798) were used to perform real-time lock mass correction. ESI positive or negative ions were used to determine the molecular weight of the components in the products and identify amino acid and acrylamide adducts. 2.12. Chlorogenic acid analysis Quantification of chlorogenic acid was performed on a Shimadzu LC-20AT system (Shimadzu, Kyoto, Japan) equipped with a diode array detector and LC-solution software. Samples (5 l) were eluted on a ZORBAX Eclipse XDB-C18 column (4.6 × 250 mm, 5 m) (Agilent Technologies Co., Ltd., USA) at 40 ◦ C with an isocratic mixture of methanol/deionized water (24:76, v/v) at a flow rate of 1.0 ml/min. Chlorogenic acid was detected at 325 nm and quantified using a standard curve generated with chlorogenic acid standard solutions. All treatments were conducted in three replicates. 3. Results and discussion 3.1. Effect of chlorogenic acid on acrylamide formation Addition of 0.5 and 5 mol/ml chlorogenic acid significantly increased acrylamide formation compared with the control (Table 1). However, when chlorogenic acid was converted to its quinone derivative, production of acrylamide was lower compared with control (Table 1). Moreover, chlorogenic acid significantly accelerated rates of acrylamide formation (P = 0.05) at the beginning of Maillard reaction (Fig. 1). These results verified our previous hypothesis that certain types of phenol antioxidants increase acrylamide formation, whereas their quinone counterparts decrease it (through H2 O2 oxidation) [17]. However, our results were contradictory to the reports by Oral et al. (2014) and Zhu et al. (2009) that chlorogenic acid inhibited acrylamide formation [15,16]. A possible explanation for the discrepancy is the difference in chlorogenic acid concentrations used: Oral et al. (2014) used a very low concentration (0.3 mol/g), while Zhu et al. (2009) used a very high concentration (1 mmol/ml). These results may followed the “antioxidant paradox” proposed by Zhang et al. [22].
4
Y. Cai et al. / Journal of Hazardous Materials 268 (2014) 1–5
Fig. 2. Changes in oxidation–reduction potential in the asparagine/glucose Maillard reaction system in the presence or absence of chlorogenic acid after heating at 160 ◦ C for different time.
Fig. 1. Effect of chlorogenic acid on acrylamide (above) and HMF (below) formation in the Maillard reaction system heating at 160 ◦ C for different time.
Since HMF generate more acrylamide than glucose when they were co-heated with asparagine ([21] and Fig. 1), we also determined the content of HMF in asparagine-glucose model reaction system. Similar to our previous finding in glutamate-glucose model reaction system [23], chlorogenic acid significantly increased HMF formation (Table 1), and it was shown in Fig. 1 that high amount of HMF was produced at 5 min and kept increase during heating for 20 min. This finding concluded that chlorogenic acid can increase acrylamide formation through promoting HMF formation.
(P < 0.05), which may be one of the underlying mechanisms by which chlorogenic acid decreases acrylamide elimination. Since acrylamide could be destructed by free radicals produced during the Maillard reaction [24], maintaining a higher redox potential (negative voltages) may prevent acrylamide from being eliminated by oxidation and free radical reactions. Previous literature reports on the effect of antioxidants on acrylamide formation are controversial. While some reported an inhibitory effect, others have reported no effect or even an enhancing effect. Jin et al. [11] provided an extensive review of literature in this area and discussed possible mechanisms underlying the seemingly contradictory results. They proposed that some antioxidants may promote acrylamide formation by triggering sucrose decomposition or acting as donors of carbonyl groups, while others may inhibit acrylamide formation by directly reacting with asparagine or trapping specific Maillard reaction products that cause asparagine precipitation and prevent lipid oxidation. Hamzalıoglu et al. [24] reported that the antioxidant curcumin reacts with asparagine to form acrylamide, while chlorogenic acid does not. We found that chlorogenic acid does not react with asparagine to form acrylamide (data not shown), and its quinone derivative, a donor of carbonyl group, even inhibits acrylamide formation. To further investigate the mechanism by which chlorogenic acid affects acrylamide formation, we investigated the effect of chlorogenic acid on acrylamide formation from 3-APA. 3.4. Effect of chlorogenic acid on acrylamide formation from 3-APA
3.2. Effect of chlorogenic acid on acrylamide elimination During Maillard reaction, acrylamide is both formed and eliminated [24]. To investigate whether chlorogenic acid affects acrylamide elimination, 13 C3 -labeled acrylamide (200 g) was added to the equimolar asparagine/glucose Maillard reaction system. Content of labeled acrylamide decreased by 17.2% and 35.2% with addition of 0.2 mmol chlorogenic acid and its quinone derivative, respectively, in contrast to the 26.8% decrease detected in the control without chlorogenic acid. These results indicated that chlorogenic acid significantly (P < 0.05) inhibited acrylamide elimination while its quinone derivative increased it slightly. 3.3. Effect of chlorogenic acid on oxidation–reduction potential in the Maillard reaction system Fig. 2 showed that chlorogenic acid significantly alleviated heating-induced decrease in oxidation–reduction potential, or increased the negative voltages of the Maillard reaction system
3-APA has been proposed as a transient intermediate and a direct precursor for acrylamide formation, which is transformed to acrylamide after deamination [25]. In this study, we found that pH significantly affected acrylamide formation from 3-APA. When 3-APA solution at pH values of 3.0, 4.0, 5.0, 6.0 and 7.0 were heated at 160 ◦ C for 15 min, 1.2, 1.7, 2.1, 3.3, and 3.9 g/ml of acrylamide were produced, respectively. We thereby studied the effect of chlorogenic acid on acrylamide formation form 3-APA in reaction solutions at pH 6.8. We found that the yield of acrylamide in the presence of chlorogenic acid was much higher than that of the control without chlorogenic acid (Fig. 3). In contrast, acrylamide formation from 3-APA decreased in the presence of the quinone derivative of chlorogenic acid, which lacks the phenol hydroxy groups. In addition, activation energy for acrylamide formation from 3-APA decreased from 173.2 to 136.6 kJ/mol in the presence of chlorogenic acid (Fig. 4). In this study, 3-APA was formed quickly in the Maillard reaction system composed of asparagine and glucose, 26.4, 66.3, 132.4, and
Y. Cai et al. / Journal of Hazardous Materials 268 (2014) 1–5
5
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.jhazmat. 2013.12.067. References
Fig. 3. The formation of acrylamide from 3-APA during heating at 160 ◦ C for different time.
Fig. 4. Arrhenius plot for acrylamide formation from 3-APA.
198.2 g/ml of 3-APA were detected (after conversion to acrylamide) at reaction times of 5, 10, 15, and 20 min, respectively, much higher than the amount of acrylamide produced at the specific time. Thus, conversion of 3-APA may play a key role in acrylamide formation during Maillard reaction. Moreover, we have detected some compounds with odd numbers of molecular weight (possibly contain one nitrogen atom) by ESI-MS, such as 179, 353, 709, 355, 373, 745, 767, etc. (supplementary materials 2), but we did not successfully obtain their MS-MS fragments possibly due to their low content. However, these findings would encorage the researchers to continue investigating the other underlying mechanism for the promotion of chlorogenic acid for acrylamide formation from 3-APA. 4. Conclusion Addition of chlorogenic acid to the asparagine/glucose Maillard reaction system significantly increased acrylamide formation and inhibited its elimination. In contrast, the quinone derivative of chlorogenic acid decreased acrylamide formation. Chlorogenic acid promoted acrylamide formation mainly through increasing HMF formation and decreasing the activation energy for conversion of 3-APA to acrylamide. Acknowledgments The authors gratefully acknowledge financial support from the National Natural Science Fund (31071596 and 31371745) and the Ministry of Science and Technology of China (No. 2012BAK01B03).
[1] E. Capuano, V. Fogliano, Acrylamide and 5-hydroxymethylfurfural (HMF): a review on metabolism, toxicity, occurrence in food and mitigation strategies, LWT-Food Sci. Technol. 44 (2011) 793–810. [2] T. Delatour, A. Perisset, T. Goldmann, S. Riediker, R.H. Stadler, Improved sample preparation to determine acrylamide in difficult matrixes such as chocolate powder, cocoa, and coffee by liquid chromatography tandem mass spectrometry, J. Agric. Food Chem. 52 (2004) 4625–4631. [3] K. Hoenicke, R. Gatermann, W. Harder, L. Hartig, Analysis of acrylamide in different foodstuffs using liquid chromatography–tandem mass spectrometry and gas chromatography–tandem mass spectrometry, Anal. Chim. Acta 520 (2004) 207–215. [4] M. Friedman, Chemistry, biochemistry, and safety of acrylamide. A review, J. Agric. Food Chem. 51 (2003) 4504–4526. [5] D. Andrzejewski, J.A.G. Roach, M.L. Gay, S.M. Musser, Analysis of coffee for the presence of acrylamide by LC-MS/MS, J. Agric. Food Chem. 52 (2004) 1996–2002. [6] K.W. Cheng, J.J. Shi, S.Y. Ou, M.F. Wang, Y. Jiang, Effects of fruit extracts on the formation of acrylamide in model reactions and fried potato crisps, J. Agric. Food Chem. 58 (1) (2010) 309–312. [7] D. Li, Y.P. Chen, Y. Zhang, B.Y. Lu, C. Jin, X.Q. Wu, Y. Zhang, Study on mitigation of acrylamide formation in cookies by 5 antioxidants, J. Food Sci. 77 (2012) C1144–C1149. [8] Z. Ciesarova, M. Suhaj, J. Horvathova, Correlation between acrylamide contents and antioxidant capacities of spice extracts in a model potato matrix, J. Food Nutr. Res. 47 (2008) 1–5. [9] A. Serpen, V. Gokmen, Evaluation of the Maillard reaction in potato crisps by acrylamide, antioxidant capacity and color, J. Food Compos. Anal. 22 (2009) 589–595. [10] A. Becalski, R. Stadler, S. Hayward, S. Kotello, T. Krakalovich, B.P.Y. Lau, V. Roscoe, S. Schroeder, R. Trelka, Antioxidant capacity of potato chips and snapshot trends in acrylamide content in potato chips and cereals on the Canadian market, Food Addit. Contam. Part A Chem. Anal. Control Expo. Risk Assess. 27 (2010) 1193–1198. [11] C. Jin, X.Q. Wu, Y. Zhang, Relationship between antioxidants and acrylamide formation: a review, Food Res. Int. 51 (2013) 611–620. [12] J. Mader, H. Rawel, L.W. Kroh, Composition of phenolic compounds and glycoalkaloids ␣-solanine and -chaconine during commercial potato processing, J. Agric. Food Chem. 57 (2009) 6292–6297. [13] J.K. Moon, H.S. Yoo, T. Shibamoto, Role of roasting conditions in the level of chlorogenic acid content in coffee beans: correlation with coffee acidity, J. Agric. Food Chem. 57 (2009) 5365–5369. [14] S. Damodaran, K.L. Parkin, O.R. Fennema, Food Chemistry, CRC Press, 2007, pp. 96–101. [15] R.P. Oral, M. Dogan, K. Sarioglu, Effects of certain polyphenols and extracts on furans and acrylamide formation in model system, and total furans during storage, Food Chem. 142 (2014) 423–429. [16] F. Zhu, Y.Z. Cai, J.X. Ke, H. Corke, Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/glucose model system by RP-HPLC-DAD, J. Sci. Food Agric. 89 (2009) 1674–1681. [17] S.Y. Ou, J.J. Shi, C.H. Huang, G.W. Zhang, J.W. Teng, Y. Jiang, B.R. Yang, Effect of antioxidants on elimination and formation of acrylamide in model reaction systems, J. Hazard. Mater. 182 (2010) 863–868. [18] F. Pedreschi, P. Moyano, K. Kaack, K. Granby, Color changes and acrylamide formation in fried potato slices, Food Res. Int. 38 (2005) 1–9. [19] L. Chen, H.H. Huang, W.B. Liu, N. Peng, X.S. Huang, Kinetics of the 5hydroxymethylfurfural formation reaction in Chinese rice wine, J. Agric. Food Chem. 58 (2010) 3507–3511. [20] Y.P. Zhang, S.Y. Ou, X.D. Guo, D.Z. Feng, Y.L. Wu, Determination of acrylamide in fried instant noodles, Modern Food Sci. Technol. 24 (2008) 593–595. [21] V. Gökmen, T. Kocadagli, N. Göncüoglu, B.A. Mogol, Model studies on the role of 5-hydroxymethyl-2-furfural in acrylamide formation from asparagine, Food Chem. 132 (2012) 168–174. [22] Y. Zhang, Y. Zhang, Effect of natural antioxidants on kinetic behavior of acrylamide formation and elimination in low-moisture asparagine–glucose model system, J. Food Eng. 85 (2008) 105–115. [23] S.S. Jiang, S.Y. Ou, E. Liang, M. Yu, C.H. Huang, G.W. Zhang, Effect of chlorogenic acid on hydroxymethylfurfural in different Maillard reaction systems, Int. Food Res. J. 20 (2013) 1239–1242. [24] M. Friedman, C.E. Levin, Review of methods for the reduction of dietary content and toxicity of acrylamide, J. Agric. Food Chem. 56 (2008) 6113–6140. [25] A. Hamzalhoglu, B.A. Mogol, R.B. Lumaga, V. Fogliano, V. Gokmen, Role of curcumin in the conversion of asparagine into acrylamide during heating, Amino Acids 44 (2013) 1419–1426.
Contents lists available at ScienceDirect
Journal of Hazardous Materials journal homepage: www.elsevier.com/locate/jhazmat
Research Article
Chlorogenic acid increased acrylamide formation through promotion of HMF formation and 3-aminopropionamide deamination Yun Cai a,1 , Zhenhua Zhang a,1 , Shanshan Jiang a,1 , Miao Yu a , Caihuan Huang a , Ruixia Qiu a , Yueyu Zou a , Qirui Zhang a , Shiyi Ou a,∗ , Hua Zhou a , Yong Wang a , Weibing Bai a , Yiqun Li b a b
Department of Food Science and Engineering, Jinan University, Guangzhou 510632, China Department of Chemistry, Jinan University, Guangzhou 510632, China
h i g h l i g h t s
g r a p h i c a l
a b s t r a c t
• Chlorogenic
acid increased the formation of acrylamide while its quinone one inhibited. • Chlorogenic acid increased acrylamide formation by enhancing HMF production. • It decreased the activation energy for conversion of 3-APA to acrylamide. • It kept high redox potential that may inhibited acrylamide elimination.
a r t i c l e
i n f o
Article history: Received 18 October 2013 Received in revised form 29 December 2013 Accepted 30 December 2013 Available online 7 January 2014 Keywords: Chlorogenic acid Acrylamide HMF 3-Aminopropionamide
a b s t r a c t This research was aimed to investigate why chlorogenic acid, presents at high concentrations in some food raw material, influences acrylamide formation. In the asparagine/glucose Maillard reaction system (pH = 6.8), addition of chlorogenic acid significantly increased acrylamide formation and inhibited its elimination. In contrast, the quinone derivative of chlorogenic acid decreased acrylamide formation. Three mechanisms may be involved for increasing acrylamide formation by chlorogenic acid. Firstly, it increased the formation of HMF, which acts as a more efficient precursor than glucose to form acrylamide. Secondly, it decreased activation energy for conversion of 3-aminopropionamide (3-APA) to acrylamide (from 173.2 to 136.6 kJ/mol), and enhances deamination from 3-APA. And thirdly, it prevented attack of the produced acrylamide from free radicals by keeping high redox potential during the Maillard reaction.
1. Introduction Acrylamide is a food contaminant formed mainly through Maillard reaction during high-temperature processing. It has neurotoxic
Abbreviations: 3-APA, 3-aminopropionamide; Asn, asparagine; CA, chlorogenic acid; Ea, activation energy; Glu, glucose; HMF, hydroxymethylfurfural; ORP, oxidation–reduction potential; PBS, phosphate buffer solution; PPO, polyphenol oxidase. ∗ Corresponding author. Tel.: +86 2085224235; fax: +86 2085226630. E-mail addresses: [email protected], [email protected] (S. Ou). 1 Contributed equally to this work. 0304-3894/$ – see front matter © 2014 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jhazmat.2013.12.067
© 2014 Elsevier B.V. All rights reserved.
and genotoxic properties, and is known to act as a carcinogen in rodents [1]. The contents of acrylamide vary among different types of food. Fried potato chips, coffee and toasted chicory contain much higher levels of acrylamide than other high temperature-processed foods [1,2], with the highest reported concentrations of 12,000, 539, and 4015 g/kg, respectively [3–5]. Food ingredients play an important role in acrylamide formation. A considerable number of antioxidants, including vitamin C, vitamin E, ferulic acid, tert-butylhydroquinone, butylated hydroxyanisole, butylated hydroxytoluene, epigallocatechin gallate, sodium erythorbate, antioxidants from bamboo leaves, tea polyphenols, and spice extracts have all been reported to influence acrylamide formation [6–11]. However, reports on relationships
2
Y. Cai et al. / Journal of Hazardous Materials 268 (2014) 1–5
between antioxidants and acrylamide contents in food have been controversial [11]. Coffee beans and potato tubers contain high concentrations of chlorogenic acid (41,640 and 1481 mg/kg, respectively) [12,13], which can be oxidized to quinone by polyphenol oxidase during processing steps such as peeling and cutting [14]. It was reported that addition of chlorogenic acid at low level (30 mol/100 g) or at very high level (1 mmol/ml) decreased acrylamide formation both in biscuits and and asparagine/glucose reaction model [15,16]. However, the mechanisms underlying this effect remain to be investigated. In the present study, we investigated the effects of chlorogenic acid at moderate concentration (50 mol/ml) and its quinone derivative (prepared using polyphenol oxidase instead of hydrogen peroxide as we previously reported) [17], on the formation of acrylamide during high-temperature processing, focusing on the mechanism by which it promotes deamination of 3-APA and HMF formation. 2. Experimental 2.1. Chemicals Chlorogenic acid, HMF, asparagine, and glucose were purchased from Aladdin Reagents Database Inc. (Shanghai, China). Acrylamide standard (>99.8%) and 13 C3 -labeled acrylamide (99%) were obtained from Sigma-Aldrich Company (St. Louis, MO, USA) and Merck-Schuchardt (Hohenbrunn, Germany), respectively. 3-Aminopropionamide hydrochloride (-alaninamide hydrochloride, 3-APA) was purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). High-performance liquid chromatography (HPLC)grade methanol and polyphenol oxidase (845 U/mg) were obtained from J. T. Baker (USA) and Worthington Biochemical Corporation (Lakewood, NJ, USA), respectively. 2.2. Effects of chlorogenic acid and its quinone derivative on acrylamide formation An equimolar asparagine/glucose Maillard reaction system was used to investigate the effects of chlorogenic acid on acrylamide formation. Each 20-ml stainless-steel test tube contained 4 ml of 0.1 M phosphate buffer solution (PBS, pH = 6.8) with different concentrations of chlorogenic acid (both phenol and quinone type, at addition levels of 0.002, 0.02, and 0.2 mmol, respectively), 1 mmol asparagine and 1 mmol glucose. The test tubes were capped with Teflon pad-filled stainless steel cap and the mixtures were heated at 160 ◦ C in an oil bath installed with a magnetic stirrer for 20 min. After cooling, the reaction mixtures were decanted into 14-ml centrifuge tubes and deionized water was added to make a total volume of 10 ml in each tube. The mixtures were then centrifuged at 4000 rpm for 20 min on an Allegra 21 R centrifuge (Beckman, USA). Concentrations of acrylamide and HMF in the supernatant were then determined. The quinone derivative of chlorogenic acid was prepared using polyphenol oxidase. Chlorogenic acid (5 mmol) and 100 mg of polyphenol oxidase were successively dissolved in 100 ml of 0.1 M PBS (pH = 6.8), and the reaction mixture was then placed in a 250-ml Erlenmeyer flask and incubated at 25 ◦ C for 60 min with shaking at 150 rpm. After the reaction was completed, polyphenol oxidase was removed using a Pellicon® XL 50 cassette and a Labscale TFF system. HPLC analysis showed that all chlorogenic acid was transformed to its quinone derivative. 2.3. Effect of chlorogenic acid or its quinone derivative on acrylamide formation during Maillard reaction A total of 4 ml of chlorogenic acid or its quinone derivative (50 mol/ml, dissolved in 0.1 M PBS, pH = 6.8) were mixed with
1 mmol of asparagine and 1 mmol of glucose in a 20-ml stainlesssteel test tube. The mixtures were heated at 160 ◦ C for 5, 10, 15, or 20 min. The amount of acrylamide formed under these conditions was then determined. Two reaction models, 1 mmol of asparagine reacted with 1 mmol of glucose or HMF without addition of chlorogenic acid in 4 ml PBS, were as the controls.
2.4. Effect of chlorogenic acid acrylamide elimination An equimolar asparagine/glucose (1 mmol) model reaction system containing 200 g of 13 C3 -labeled acrylamide and 0.2 mmol of chlorogenic acid or its quinone derivative in 0.1 M PBS (pH = 6.8) was used to assess the effect of chlorogenic acid on the elimination of acrylamide during the reaction process. The same system containing no chlorogenic acid or its quinone derivative was used as control.
2.5. Effect of chlorogenic acid on oxidation–reduction potential in the Maillard reaction system Oxidation–reduction potential of the supernatant of the Maillard reaction system described above was determined in the presence or absence of 0.2 mmol of chlorogenic acid at different reaction times using an ORP-422 model oxidation–reduction potential detector (Beijing Zhongxi Yuanda Scientific Instrument Co., Ltd., Beijing, China).
2.6. Effect of chlorogenic acid on acrylamide formation from 3-aminopropionamide (3-APA) pH value of 2.5 mM 3-APA solution was adjusted to 3.0, 4.0, 5.0, 6.0, or 7.0 using 0.1 M NaOH. Each solution (4 ml) was placed in a stainless-steel test tube and heated in an oil bath at 160 ◦ C for 15 min. The amounts of acrylamide produced under these conditions were then determined. Based on results obtained from the effect of pH, 2 ml of 5.0 mM 3-APA (dissolved in 0.1 M PBS, pH = 6.8) and 2 ml of chlorogenic acid or its quinone derivative (0.1 mmol/ml dissolved in 2 ml of 0.1 M PBS, pH = 6.8) were mixed, placed in a stainless-steel test tube and heated in an oil bath at 160 ◦ C for 5, 10, 15, and 20 min. The amounts of acrylamide produced were then determined.
2.7. Activation energies for the formation of acrylamide from 3-APA A solution (4 ml) containing 10 mol of 3-APA and 0.2 mmol of chlorogenic acid (in 0.1 M PBS buffer, pH = 6.8) was heated in an oil bath at 120, 130, 140, 150, 160, and 170 ◦ C for 5, 10, and 15 min, respectively. Activation energy for the conversion of 3-APA to acrylamide under each specific condition was determined as follows. Rate constant at a specific reaction temperature was obtained from the slope of a linear plot of the amount of acrylamide produced against reaction time. The effect of temperature on reaction rate constant k was expressed by the Arrhenius equation [18,19]: ln k = ln A −
Ea RT
where R is universal gas constant (8.314 J/K mol), T is temperature, k is reaction rate constant, Ea is activation energy, and A is frequency factor. A plot of (−ln K) versus 1/T yields a straight line with a slope of Ea /R.
Y. Cai et al. / Journal of Hazardous Materials 268 (2014) 1–5
3
Table 1 Effect of chlorogenic acid on acrylamide formation in the asparagine/glucose Maillard reaction system after heating at 160 ◦ C for 15 min (pH = 6.8). CA added (mol/ml)
Acrylamide (g/ml) HMF (g/ml) a
0
59.3 ± 3.2a 45.6 ± 3.6
0.5
5
50
No PPO treated
PPO treated
No PPO treated
PPO treated
No PPO treated
PPO treated
62.8 ± 2.7 56.3 ± 3.2
43.7 ± 3.3 44.7 ± 3.1
68.3 ± 6.7 75.7 ± 2.9
31.5 ± 2.8 39.2 ± 2.9
79.8 ± 5.4 83.5 ± 3.6
26.7 ± 3.2 37.7 ± 2.5
Means ± SD (n = 3).
2.8. Acrylamide analysis Acrylamide determination was performed as described previously [20]. Samples (4.8 ml each) were mixed with 0.2 ml of 13 C -labeled acrylamide internal standard (2 g/ml) and subjected 3 to liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS) analysis on a Shimadzu LC-20AT system (Shimadzu, Kyoto, Japan) equipped with an LC-10ATvp pump, a SIL-HTa autosampler, and a CTO-10Asvp temperature-controlled column oven, which was coupled to an API3000 MS detector with an atmospheric pressure chemical ionization interface. Samples (20 l) were eluted on a YMC-Pack ODS-AQ C18 column (150 mm × 4.6 mm, 5 m) at 40 ◦ C with an isocratic mixture of 0.5% methanol/0.1% acetic acid in deionized water at a flow rate of 0.5 ml/min. MS/MS was performed in positive ESI mode. Transitions m/z 72 → 55 and 75 → 58 were used in identification and quantification of acrylamide and 13 C3 -labeled acrylamide, respectively. 2.9. HMF analysis HMF determination was performed according to the method described by Chen et al. [19] with some modifications. Samples were filtered through a 0.45 m membrane and analyzed on a Shimadzu LC-20AT system (Shimadzu, Kyoto, Japan) equipped with a Zorbax SB-Aq column (4.6 mm × 250 mm, 5 m) (Agilent Technologies Co., Ltd., USA), a diode array detector, and LC-solution software. Samples (5 l each) were eluted with 5% methanol in water at a flow rate of 0.5 ml/min under isocratic conditions at 40 ◦ C. HMF was detected by absorbance at 284 nm and quantified using a standard curve generated with HMF standard solutions. 2.10. Analysis of 3-APA 3-APA was determined according to the method described by Gökmen et al. [21]. Samples were analyzed on an Acquity UPLCQuattro Premier XE (Waters, USA) coupled to an Agilent 6130 MS detector, which was equipped with an electrospray ionization (ESI) interface and MassLynx V4.1 data analysis software. Samples (5 l each) were separated on a Waters Acquity UPLC BEH C8 column (1.0 × 50 mm, 1.7 m) using an isocratic mixture of methanol:10 mM formic acid (70:30, v/v) as the mobile phase at a flow rate of 0.4 ml/min at 40 ◦ C. The MS detector was operated in positive ionization mode at drying gas (N2 ) flow rate of 800 l/h and capillary voltage of 0.5 kV. Signal response of the precursor ion [M + H]+ with m/z of 89 was used for quantification of 3-APA. Concentrations of 3-APA were calculated using a standard curve (y = 933.01x + 8642.2, R2 = 0. 9995) generated with 3-APA standard solutions of 10–100 ng/ml. 2.11. Determination of products formed by co-heating 3-APA with chlorogenic acid Samples (10 l each) were analyzed on a liquid chromatography–mass spectroscopy (LC–MS) system composed of a 4000Q–TRAP mass spectrometer (Applied Biosystem Sciex) and a Agilent–1100 HPLC system equipped with an Angilent
AORABAX Bonus RP column (2.1 mm × 150 mm, 5 m). Samples were eluted with pure water at a flow rate of 0.3 ml/min under isocratic conditions at 40 ◦ C. Full scan MS was conducted using ESI with selected ion recording. ESI positive or negative ions (±H+ ) were used to determine the molecular weight of product components and identify amino acid and acrylamide adducts. The newly formed nitrogen compounds were determined using an Agilent 6210 LC/TOF-MS with an Agilent Zorbax SB-C18 column (2.1 mm × 30 mm, 3.5 m). The TOF-MS operation parameters were as follows: drying gas (N2 ) at 9 l/min flow rate; drying gas temperature, 300 ◦ C; nebulising gas (N2 ) pressure, 30 psi; capillary voltage, 3500 V; skimmer voltage, 65 V and fragmentor voltage, 300 V. Elution was performed at a flow rate of 0.4 ml/min under isocratic conditions and using 10% methanol aqueous solution as the mobile phase. TOF-MS scanning results were collected as centroids from m/z 100 to 500. Two reference mass compounds, a lock mass solution including purine (C5 H4 N4 at m/z 121.050873) and hexakis (1H,1H,3H-tetrafluoropentoxy)phosphazene (C18 H18 O6 N3 P3 F24 at m/z 922.009798) were used to perform real-time lock mass correction. ESI positive or negative ions were used to determine the molecular weight of the components in the products and identify amino acid and acrylamide adducts. 2.12. Chlorogenic acid analysis Quantification of chlorogenic acid was performed on a Shimadzu LC-20AT system (Shimadzu, Kyoto, Japan) equipped with a diode array detector and LC-solution software. Samples (5 l) were eluted on a ZORBAX Eclipse XDB-C18 column (4.6 × 250 mm, 5 m) (Agilent Technologies Co., Ltd., USA) at 40 ◦ C with an isocratic mixture of methanol/deionized water (24:76, v/v) at a flow rate of 1.0 ml/min. Chlorogenic acid was detected at 325 nm and quantified using a standard curve generated with chlorogenic acid standard solutions. All treatments were conducted in three replicates. 3. Results and discussion 3.1. Effect of chlorogenic acid on acrylamide formation Addition of 0.5 and 5 mol/ml chlorogenic acid significantly increased acrylamide formation compared with the control (Table 1). However, when chlorogenic acid was converted to its quinone derivative, production of acrylamide was lower compared with control (Table 1). Moreover, chlorogenic acid significantly accelerated rates of acrylamide formation (P = 0.05) at the beginning of Maillard reaction (Fig. 1). These results verified our previous hypothesis that certain types of phenol antioxidants increase acrylamide formation, whereas their quinone counterparts decrease it (through H2 O2 oxidation) [17]. However, our results were contradictory to the reports by Oral et al. (2014) and Zhu et al. (2009) that chlorogenic acid inhibited acrylamide formation [15,16]. A possible explanation for the discrepancy is the difference in chlorogenic acid concentrations used: Oral et al. (2014) used a very low concentration (0.3 mol/g), while Zhu et al. (2009) used a very high concentration (1 mmol/ml). These results may followed the “antioxidant paradox” proposed by Zhang et al. [22].
4
Y. Cai et al. / Journal of Hazardous Materials 268 (2014) 1–5
Fig. 2. Changes in oxidation–reduction potential in the asparagine/glucose Maillard reaction system in the presence or absence of chlorogenic acid after heating at 160 ◦ C for different time.
Fig. 1. Effect of chlorogenic acid on acrylamide (above) and HMF (below) formation in the Maillard reaction system heating at 160 ◦ C for different time.
Since HMF generate more acrylamide than glucose when they were co-heated with asparagine ([21] and Fig. 1), we also determined the content of HMF in asparagine-glucose model reaction system. Similar to our previous finding in glutamate-glucose model reaction system [23], chlorogenic acid significantly increased HMF formation (Table 1), and it was shown in Fig. 1 that high amount of HMF was produced at 5 min and kept increase during heating for 20 min. This finding concluded that chlorogenic acid can increase acrylamide formation through promoting HMF formation.
(P < 0.05), which may be one of the underlying mechanisms by which chlorogenic acid decreases acrylamide elimination. Since acrylamide could be destructed by free radicals produced during the Maillard reaction [24], maintaining a higher redox potential (negative voltages) may prevent acrylamide from being eliminated by oxidation and free radical reactions. Previous literature reports on the effect of antioxidants on acrylamide formation are controversial. While some reported an inhibitory effect, others have reported no effect or even an enhancing effect. Jin et al. [11] provided an extensive review of literature in this area and discussed possible mechanisms underlying the seemingly contradictory results. They proposed that some antioxidants may promote acrylamide formation by triggering sucrose decomposition or acting as donors of carbonyl groups, while others may inhibit acrylamide formation by directly reacting with asparagine or trapping specific Maillard reaction products that cause asparagine precipitation and prevent lipid oxidation. Hamzalıoglu et al. [24] reported that the antioxidant curcumin reacts with asparagine to form acrylamide, while chlorogenic acid does not. We found that chlorogenic acid does not react with asparagine to form acrylamide (data not shown), and its quinone derivative, a donor of carbonyl group, even inhibits acrylamide formation. To further investigate the mechanism by which chlorogenic acid affects acrylamide formation, we investigated the effect of chlorogenic acid on acrylamide formation from 3-APA. 3.4. Effect of chlorogenic acid on acrylamide formation from 3-APA
3.2. Effect of chlorogenic acid on acrylamide elimination During Maillard reaction, acrylamide is both formed and eliminated [24]. To investigate whether chlorogenic acid affects acrylamide elimination, 13 C3 -labeled acrylamide (200 g) was added to the equimolar asparagine/glucose Maillard reaction system. Content of labeled acrylamide decreased by 17.2% and 35.2% with addition of 0.2 mmol chlorogenic acid and its quinone derivative, respectively, in contrast to the 26.8% decrease detected in the control without chlorogenic acid. These results indicated that chlorogenic acid significantly (P < 0.05) inhibited acrylamide elimination while its quinone derivative increased it slightly. 3.3. Effect of chlorogenic acid on oxidation–reduction potential in the Maillard reaction system Fig. 2 showed that chlorogenic acid significantly alleviated heating-induced decrease in oxidation–reduction potential, or increased the negative voltages of the Maillard reaction system
3-APA has been proposed as a transient intermediate and a direct precursor for acrylamide formation, which is transformed to acrylamide after deamination [25]. In this study, we found that pH significantly affected acrylamide formation from 3-APA. When 3-APA solution at pH values of 3.0, 4.0, 5.0, 6.0 and 7.0 were heated at 160 ◦ C for 15 min, 1.2, 1.7, 2.1, 3.3, and 3.9 g/ml of acrylamide were produced, respectively. We thereby studied the effect of chlorogenic acid on acrylamide formation form 3-APA in reaction solutions at pH 6.8. We found that the yield of acrylamide in the presence of chlorogenic acid was much higher than that of the control without chlorogenic acid (Fig. 3). In contrast, acrylamide formation from 3-APA decreased in the presence of the quinone derivative of chlorogenic acid, which lacks the phenol hydroxy groups. In addition, activation energy for acrylamide formation from 3-APA decreased from 173.2 to 136.6 kJ/mol in the presence of chlorogenic acid (Fig. 4). In this study, 3-APA was formed quickly in the Maillard reaction system composed of asparagine and glucose, 26.4, 66.3, 132.4, and
Y. Cai et al. / Journal of Hazardous Materials 268 (2014) 1–5
5
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.jhazmat. 2013.12.067. References
Fig. 3. The formation of acrylamide from 3-APA during heating at 160 ◦ C for different time.
Fig. 4. Arrhenius plot for acrylamide formation from 3-APA.
198.2 g/ml of 3-APA were detected (after conversion to acrylamide) at reaction times of 5, 10, 15, and 20 min, respectively, much higher than the amount of acrylamide produced at the specific time. Thus, conversion of 3-APA may play a key role in acrylamide formation during Maillard reaction. Moreover, we have detected some compounds with odd numbers of molecular weight (possibly contain one nitrogen atom) by ESI-MS, such as 179, 353, 709, 355, 373, 745, 767, etc. (supplementary materials 2), but we did not successfully obtain their MS-MS fragments possibly due to their low content. However, these findings would encorage the researchers to continue investigating the other underlying mechanism for the promotion of chlorogenic acid for acrylamide formation from 3-APA. 4. Conclusion Addition of chlorogenic acid to the asparagine/glucose Maillard reaction system significantly increased acrylamide formation and inhibited its elimination. In contrast, the quinone derivative of chlorogenic acid decreased acrylamide formation. Chlorogenic acid promoted acrylamide formation mainly through increasing HMF formation and decreasing the activation energy for conversion of 3-APA to acrylamide. Acknowledgments The authors gratefully acknowledge financial support from the National Natural Science Fund (31071596 and 31371745) and the Ministry of Science and Technology of China (No. 2012BAK01B03).
[1] E. Capuano, V. Fogliano, Acrylamide and 5-hydroxymethylfurfural (HMF): a review on metabolism, toxicity, occurrence in food and mitigation strategies, LWT-Food Sci. Technol. 44 (2011) 793–810. [2] T. Delatour, A. Perisset, T. Goldmann, S. Riediker, R.H. Stadler, Improved sample preparation to determine acrylamide in difficult matrixes such as chocolate powder, cocoa, and coffee by liquid chromatography tandem mass spectrometry, J. Agric. Food Chem. 52 (2004) 4625–4631. [3] K. Hoenicke, R. Gatermann, W. Harder, L. Hartig, Analysis of acrylamide in different foodstuffs using liquid chromatography–tandem mass spectrometry and gas chromatography–tandem mass spectrometry, Anal. Chim. Acta 520 (2004) 207–215. [4] M. Friedman, Chemistry, biochemistry, and safety of acrylamide. A review, J. Agric. Food Chem. 51 (2003) 4504–4526. [5] D. Andrzejewski, J.A.G. Roach, M.L. Gay, S.M. Musser, Analysis of coffee for the presence of acrylamide by LC-MS/MS, J. Agric. Food Chem. 52 (2004) 1996–2002. [6] K.W. Cheng, J.J. Shi, S.Y. Ou, M.F. Wang, Y. Jiang, Effects of fruit extracts on the formation of acrylamide in model reactions and fried potato crisps, J. Agric. Food Chem. 58 (1) (2010) 309–312. [7] D. Li, Y.P. Chen, Y. Zhang, B.Y. Lu, C. Jin, X.Q. Wu, Y. Zhang, Study on mitigation of acrylamide formation in cookies by 5 antioxidants, J. Food Sci. 77 (2012) C1144–C1149. [8] Z. Ciesarova, M. Suhaj, J. Horvathova, Correlation between acrylamide contents and antioxidant capacities of spice extracts in a model potato matrix, J. Food Nutr. Res. 47 (2008) 1–5. [9] A. Serpen, V. Gokmen, Evaluation of the Maillard reaction in potato crisps by acrylamide, antioxidant capacity and color, J. Food Compos. Anal. 22 (2009) 589–595. [10] A. Becalski, R. Stadler, S. Hayward, S. Kotello, T. Krakalovich, B.P.Y. Lau, V. Roscoe, S. Schroeder, R. Trelka, Antioxidant capacity of potato chips and snapshot trends in acrylamide content in potato chips and cereals on the Canadian market, Food Addit. Contam. Part A Chem. Anal. Control Expo. Risk Assess. 27 (2010) 1193–1198. [11] C. Jin, X.Q. Wu, Y. Zhang, Relationship between antioxidants and acrylamide formation: a review, Food Res. Int. 51 (2013) 611–620. [12] J. Mader, H. Rawel, L.W. Kroh, Composition of phenolic compounds and glycoalkaloids ␣-solanine and -chaconine during commercial potato processing, J. Agric. Food Chem. 57 (2009) 6292–6297. [13] J.K. Moon, H.S. Yoo, T. Shibamoto, Role of roasting conditions in the level of chlorogenic acid content in coffee beans: correlation with coffee acidity, J. Agric. Food Chem. 57 (2009) 5365–5369. [14] S. Damodaran, K.L. Parkin, O.R. Fennema, Food Chemistry, CRC Press, 2007, pp. 96–101. [15] R.P. Oral, M. Dogan, K. Sarioglu, Effects of certain polyphenols and extracts on furans and acrylamide formation in model system, and total furans during storage, Food Chem. 142 (2014) 423–429. [16] F. Zhu, Y.Z. Cai, J.X. Ke, H. Corke, Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/glucose model system by RP-HPLC-DAD, J. Sci. Food Agric. 89 (2009) 1674–1681. [17] S.Y. Ou, J.J. Shi, C.H. Huang, G.W. Zhang, J.W. Teng, Y. Jiang, B.R. Yang, Effect of antioxidants on elimination and formation of acrylamide in model reaction systems, J. Hazard. Mater. 182 (2010) 863–868. [18] F. Pedreschi, P. Moyano, K. Kaack, K. Granby, Color changes and acrylamide formation in fried potato slices, Food Res. Int. 38 (2005) 1–9. [19] L. Chen, H.H. Huang, W.B. Liu, N. Peng, X.S. Huang, Kinetics of the 5hydroxymethylfurfural formation reaction in Chinese rice wine, J. Agric. Food Chem. 58 (2010) 3507–3511. [20] Y.P. Zhang, S.Y. Ou, X.D. Guo, D.Z. Feng, Y.L. Wu, Determination of acrylamide in fried instant noodles, Modern Food Sci. Technol. 24 (2008) 593–595. [21] V. Gökmen, T. Kocadagli, N. Göncüoglu, B.A. Mogol, Model studies on the role of 5-hydroxymethyl-2-furfural in acrylamide formation from asparagine, Food Chem. 132 (2012) 168–174. [22] Y. Zhang, Y. Zhang, Effect of natural antioxidants on kinetic behavior of acrylamide formation and elimination in low-moisture asparagine–glucose model system, J. Food Eng. 85 (2008) 105–115. [23] S.S. Jiang, S.Y. Ou, E. Liang, M. Yu, C.H. Huang, G.W. Zhang, Effect of chlorogenic acid on hydroxymethylfurfural in different Maillard reaction systems, Int. Food Res. J. 20 (2013) 1239–1242. [24] M. Friedman, C.E. Levin, Review of methods for the reduction of dietary content and toxicity of acrylamide, J. Agric. Food Chem. 56 (2008) 6113–6140. [25] A. Hamzalhoglu, B.A. Mogol, R.B. Lumaga, V. Fogliano, V. Gokmen, Role of curcumin in the conversion of asparagine into acrylamide during heating, Amino Acids 44 (2013) 1419–1426.
