Skip to main content
NCBI home page
Journal of Food Science and Technology logoLink to Journal of Food Science and Technology
. 2020 Sep 3;58(7):2538–2546. doi: 10.1007/s13197-020-04760-4

Comparison of trapping efficiency of dicarbonyl trapping agents and reducing agents on reduction of furanoic compounds in commercially available soy sauce varieties

Zahra Batool 1, Dan Xu 1, Longmei Weng 1, Xia Zhang 1, Bing Li 1,✉, Lin Li 1,2,✉
PMCID: PMC8196137  PMID: 34194090

Abstract

This study has conducted to determine the concentration levels of furan, furfural and 2-methylfuran in the six commercially available soy sauce varieties by an optimized Gas Chromatography Tripple Quadruple Mass Spectrometry. The extraction of analytes was performed by solid phase microextraction using 50/30 µm CAR/DVB/PDMS fibre in 25 min with 20% NaCl concentration under 35 °C and separation was performed on HP5-MS column. Different concentration levels of furan, furfural and 2-methylfuran were determined which differed significantly at p < 0.05. A total of four metal ions (Iron sulphate, magnesium sulphate, calcium sulphate and sodium sulfite), ascorbic acid and natural antioxidants (epicatechin, epigalactocatechin and kempferol) were added in the soy sauce samples by simulating sterilization conditions. A higher reduction level was given by calcium sulphate with reduction upto 90.68%, 89.07% and 65.42% for furan, furfural and 2-methylfuran, respectively, in comparison with other metal ions. Since iron sulphate and ascorbic acid have triggered formation of furanoic compounds upto high levels instead of reduction. Moreover, from natural antioxidants, epicatechin and kemferol have provided more reduction levels around 89.66%, 90.14% and 78.75% for furan, furfural and 2-methylfuran, respectively by sterilization with catichen and 88.80%, 90.36% and 84.29% for furan, furfural and 2-methylfuran, respectively by sterilization with kempferol than epigalactocatechin. Moreover, this method was also validated in terms of sensitivity, recovery, relative standard deviation and LOD and LOQ for all analytes.

Keywords: Furan, Soy Sauce, Carcinogen, GC/TQ-MS, SPME

Introduction

Furan is a heterocyclic and possible carcinogen which is mainly formed in various heat processed commercially available food items (Rufian-Henares et al. 2009; Crews and Castle 2007). Furan is a colourless chemical compound relatively higher volatility having 31 °C boiling point (Bolger et al. 2009). International Agency for research on cancer (IARC) has considered it as a hazardous chemical and listed in the category of possibly carcinogenic to humans (Group 2B) (IARC 1995). Thermal treatment of food at higher temperature could be the most common cause of furan formation, while processing (Nie et al. 2013). It has also considered that furan formation could involve different precursors and intermediates that could trigger its formation during different heat processing conditions (Anese et al. 2013; Mariotti et al. 2012; Locas and Yaylayan 2004). Maillard reaction has also been considered as a major pathway, triggering furan formation under different applied heat treatments (Limacher et al. 2008). Maillard reaction occurs between specific amino acids and carbonyl group of reducing sugars. It has been observed that this reaction has considerably desirable effects on flavor and quality of heat treated food, however, some hazardous and carcinogenic compounds have also been produced during this treatment such as furan (Kim et al. 2010, 2009; Zoller et al. 2007). Regardless of furan, other derivatives of furan, several oxygenated and alkylated derivatives of furan have also been formed during food processing, such as furfural, 2-acetylfuran, furfural alcohol and 2-methylfuran and recognized as toxic and harmful to both animals and humans (Condurso et al. 2018; Okaro and Lachenmeier 2017; EFSA 2011).

In Asian countries such as Korea, China, Japan, Indonesia and Thailand, a number of traditional foods undergo thermal treatment and results in occurrence of maillard reaction, triggering formation harmful compounds (Feng et al. 2013; Zhang and Tao 2009; Kim and Lee 2008). Soy sauce production has gained attention in these above mentioned counties and especially in China industry because of good taste and great demand from public to use as daily seasoning in their food. However, different chemical changes could occur during fermentation at relatively higher temperatures and different aging times and fermentation conditions. These changes can trigger the production of some harmful and tasteless chemicals by maillard reaction at certain higher temperature conditions. Severall past studies have shown the prevalence of furan levels in naturally brewed soy sauce and has given a range of 44.32–178 ng/mL (Wu et al. 2014; Feng et al. 2013; Kim et al. 2010; Zhang and Tao 2009; Zoller et al. 2007) which is considerably higher than other food stuff. Hence, it might be expected that people might be exposed regularly to these chemicals because of routinely usage of soy sauce in their normal diet. Hence, a number of strategies such as thermal input reduction and modified fermentation conditions have been used for mitigation of these compounds in fermented soy sauce (Hoang et al. 2016; Anese et al. 2013). Since, food additives such as catichen and kempferol are phenolic compounds and becoming famous because of their antioxidant, antimutagenic and anticarcinogenic properties and can be added in food to improve its aroma, storage properties and appearance (Kim et al. 2015; Kumar et al. 2012; Lee et al. 2013; Zhu et al. 2009; Gramza et al. 2005).

Hence, this study has focussed on simultaneous determination of these hazardous chemicals in soy sauce and for the first time on addition of different food additives and natural antioxidants to commercially available soy sauces and analyzed their trapping efficiency and inhibition of furan and its most prevalent derivatives in soy sauce under sterilized conditions in order to improve its quality.

Materials and methods

Chemical reagents and materials

Furan (≥ 99%), furfural (99%) were purchased from Aladine Chemicals Co., Ltd (China), and 2-methylfuran (99%, 2-MF) were purchased from Sigma Aldrich (St. Louis, USA). High purity HPLC grade water was purchased from Watson Chemicals. Co., Ltd (China) and Sodium chloride (NaCl, AR) was obtained from Sigma Aldrich (St. Louis, USA). Food additives, iron sulphate n-hydrate (Fe2+, 60–80%), magnesium sulphate (Mg2+, 99%) were obtained from Aladine Chemicals Co., Ltd (China). Calcium sulphate dehydrate (Ca2+, 97%), sodium sulfite (Na+, 98%) were purchased from Sigma-Aldrich Corporation (St. Louis, USA). Ascorbic Acid was purchased from Sigma Aldrich (St. Louis, USA). Epicatechin (EC) and epigallocatechin gallate (EGCG) and kempferol (Kf) were obtained from Aladine Chemicals Co., Ltd (China). Six soy sauce varieties were purchased from commercial superstores in Guangzhou, China.

Preparation of samples for analysis of furan and its derivatives

For preparation of soy sauce samples, 40 mL headspace vials were used to add HPLC grade water (10 mL) and 10 mL of soy sauce. Then vials were sealed with silicon-PTFE septa caps and stored at 4 °C until analysis. This process was repeated in triplicate and results were recorded.

Sample preparation for analysis of trapping efficiency of inhibitors

This method was performed according to method of Kim et al. (2015) for Soy sauce sterilization with different antioxidants after some modifications. Same molar concentrations of about 0.1 mg/mL of all food additives were added into headspace vials containing 10 mL water and soy sauce (10 mL) prior to sterilization process. Then silicon-PTFE septa caps were used to completely seal all vials and heated at 75 °C for 20 min on a heating plate. Vials containing sterilized soy sauce and different additives, were placed in the refrigerator at 4 °C until analysis. This sterilized soy sauce was used for analysis of rate furan inhibition and its derivatives and it has also used to analyse the trapping efficiency of different inhibiting food additives and natural antioxidants.

Preparation of stock solutions and validation of analytical method

Stock solutions of furan, furfural and 2-methylfuran furan were prepared in separate headspace vials by adding analytes via a gastight syringe in cold methanol. These stock solutions were prepared fresh on weekly basis. Further working solutions were prepared daily by adding 100 μl of refrigerated solutions and 15 mL of HPLC grade water. All vials were sealed with silicon-PTFE septa caps and stored at 4 °C until analysis. Following validation parameters were used for method validation for furan, furfural and 2-methylfuran in soy sauce model system: Linearity, specificity, correlation coefficient (R2), repeatability, recovery, limit of detection (LOD) and limit of quantification (LOQ).

Head space solid phase microextraction (HS-SPME)

In optimization of HS-SPME, CAR/DVB/PDMS fibre with 50/30 μm film thickness from (Spelco, Bellefonte, PA, USA) was used to extract analytes under the optimized extraction conditions including extraction time, extraction temperature, salt concentrations and stirring speed. To optimize extraction time, about three extraction times were selected in this study i.e. 15, 20 and 30 min. Three extraction temperatures were also used to optimize parameter with values as 25, 35 and 40 °C. Total four stirring speeds (500, 600, 700 and 800 rpm) have been selected to get more considerable stirring speed for extraction process. Salt effect was also observed by adding four different concentrations of NaCl in the sample with 10%, 15%, 20% and 25% (W/V). In this current study, 15 mL headspace vials were used to fill up 5 g of each sample and added about 2.5 mL of 20% (W/V) NaCl.

All headspace vials were equipped with miniert valves to introduce the fibre inside vials without piercing any septum to avoid any extraneous peak due to septum bleeding. Heater temperature was set at 35 °C and vials were kept over it one by one for analytes extraction using divinlybenzene/carboxen/polysimethylsiloxane (DVB/CAR/PDMS) fibre having 50/30 μm film thickness (Spelco, Bellefonte, PA,USA) and which was also housed in the manual holder (Spelco, Bellefonte, PA,USA). All fibres were conditioned prior to use according to the instructions by Manufacturer Company. All samples were equilibrated for 20 min on heater at 35 °C and extraction was performed for next 15 min during continues stirring at 700 rpm with small magnet kept inside vials. SPME fibre was ejected from vials after extraction and introduced onto splitless injector of GC–MS, which was maintained at 250 °C. SPME fibre was kept onto Gas Chromatography Tripple Quadruple Mass Spectrometry (GC-TQ/MS) injector for 5 min for desorption of volatiles and to assure complete fibre cleaning of fibre.

GC-TQ/MS

An Agilent technologies 7890B Gas Chromatograph grouped with 7000C Triple Quadruple Mass Spectrometer (GC-TQ/MS) and fitted with HP-5MS column (30 m * 0.25 mm * 0.25 μm) was used to separate and analyze the volatiles from different samples. Helium was kept as a carrier gas with constant flow rate of 1 mL/min. Split GC inlet mode (5:1) was used to inject the volatiles from SPME needle with injector temperature about 250 °C which was held for 5 min. GC oven temperature program was initially set at 35 °C (5 min) and then increased up to 50 °C at rate of 3 °C/min, then further increased up to 250 °C at rate of 20 °C/min, and kept for 5 min. The transfer line temperature was maintained at 250 °C. Mass spectrometer was operated in electron impact (EI) mode having electron energy about 70 eV. A solvent delay was set for 1 min. All quantitative analysis of furan and its derivatives was performed in selective ion monitoring mode and list of ions used for analysis has been given in Table 1. All analytes, released from the sample matrix were identified after comparison of their retention times and abundance ratio with those of standard compounds that were used to make linear curves for calculation of exact concentration of each compound in sample matrix.

Table 1.

Different compounds with their retention times and ions detail

Compound Retention time (min) Quantifying ion (m/z) Qualifier ion (m/z) Qualifier ion (m/z)
Furan 1.56 68 39 0
Furfural 7.0 96 95 39
2-Methylfuran 2.14 138 81 82
Open in a new tab

Quantification

All calibration standard solutions were prepared by serial dilution from 500 ng/mL stock solution. Different concentrations of standards were made different according to their prevalence in samples. For furan (≥ 99.5%), concentration levels of standards were ranged from 1.02 to 100.02 ng/mL, 1.01 to 100.01 ng/mL for furfural (≥99%) and 1.00–100.0 ng/mL for 2-methylfuran (≥98%). The calibration curves were generated between concentrations and relative peak area of standards. Peak areas of standards were integrated automatically by ChemStation® and determination coefficients were calculated by linear regression model in Microsoft Excel®. An external calibration method was applied for calculation of each analyte in samples.

Method validation parameters

Validation parameters including precision, recovery, linearity, specificity, limit of detection and limit of quantification were determined. Standards with different concentration were analyzed to get method linearity and determination coefficients (R2) with SPME following GC-TQ/MS. Triplicate measurements at three different concentrations (1.0, 10.0 and 50 ng/mL) were used to assess the repeatability of method. Method precision was expressed by relative standard deviation (RSD%). Limits of detection (LOD) and limits of quantification (LOQ) were determined at S/N = 3 and S/N = 10 ratios for LOD and LOQ, respectively. The specificity was also determined by analyzing blank samples in triplicate. Method recovery was calculated by standard addition method spiking different levels of standards in blank sample as performed for linearity calculation.

Results and discussion

Optimization of HS-SPME and GC-TQ/MS

Before defined procedure of HS-SPME, parameters of GC including carrier gas flow, capillary column, oven temperature, injection mode, and detector parameters were investigated for accuracy, optimal response and analytes separation. HP-5MS column (30 m * 0.25 mm * 0.25 μm) was selected for optimal separation of concerned analytes with retention times as 1.56 for furan, 2.14 min for 2-methylfuran and 7 min for furfural. To ensure complete transfer of analytes and increase method sensitivity, Split GC inlet mode (5:1) was used. All compounds were baseline separated ( Fig. 1). 250 °C was determined to be optimal temperature for desorption of analytes within 5 min, without any carryover in following blank injection. A best response was gained from detector temperature and flow rate of hydrogen gas through direct injection of all mixed standards.

Fig. 1.

Fig. 1

Open in a new tab

Separation of analyte Standards on HP5-MS column in less than 7.5 min during GC/TQ MS analysis

The efficacy and sensitivity of CAR/PDMS fibre for better extraction of analytes from different foods and beverages have been proved in a number of studies (Hu et al. 2016; Petisca 2014). In the current study, more sensitive analysis of oxygenated and alkylated derivative of furan from different soy sauce samples was needed. As far as, the furan is a highly volatile compound with very small molecular structure. Therefore, extraction of furan and derivatives need more sensitive fibres having more sensitivity to capture these analytes. Hence, CAR/DVB/PDMS fibre was selected for analytes extraction from this sample matrix because of presence of three combinations of CAR/DVB/PDMS altogether as compared with DVB/PDMS and only PDMS containing fibre, this fiber has become a more sensitive choice for determination of furanoic compounds. The most important factor during extraction is the extraction temperature which affects the adsorption of compounds. It has been reported to influence analytes partition coefficients and further effect the extraction efficiency of SPME (Sarafraz-Yazdi et al. 2012).

In the current study, the temperatures ranging from 25 to 40∘C were evaluated and 25–35∘C have provided efficient fibre extraction. The extracted amount of analytes decreased from 35 to 40∘C to some extent. It might be due to the elevation in temperature which promotes the analytes transfer from liquid phase to headspace and leads to a decrement in partition coefficient of analytes among the headspace of vials and fibre coatings. Concerning exothermic property of extraction process (Altaki et al. 2011), 35 °C was selected for all subsequent experimental analysis. Appropriate extraction time is required for achieving distribution equilibrium of analytes between the three phases, the headspace phase, fibre coating and solution matrix. The effect of different extraction times ranging from 15 to 35 min was examined for furan, furfural and 2-methylfuran. The highest extraction efficiency of analytes extraction was optimized in 25 min. The decreasing extraction efficiency after 25 min might due to the competition, occurred between analytes and solution matrix (Januszkiewicz et al. 2008).

Agitation is an important phenomenon to enhance mass migration and to accelerate the thermodynamic equilibrium. String speed from 500 to 800 rpm was evaluated for extraction of analytes and 700 rpm has given best response of all analytes. Higher speed might decrease the extraction quantity of analytes due to the unstable violent agitation of samples. Another important extraction factor is the salting out effect. The addition of salt to the sample solution would decrease aqueous solubility of analytes and increase the distribution constant between the sample matrix and fibre coating sorbent (Verzera et al. 2010). Extraction efficiency of analytes was examined by adding different concentrations of NaCl, ranging from 10 to 25% (W/V). Response of analytes was increased from 10 to 20%. Hence, 20% NaCl (w/v) was selected as optimized salt concentration for subsequent analysis of analytes.

Method validation

The optimized HS-SPME GC/MS method has demonstrated an excellent linear relationship between peak area and concentration of four analytes with determination coefficients (R2) ≥ 0.99 and linear ranges at 1.02–100.02 ng/mL for furan, 1.03–100.03 ng/mL for furfural, and 1.00–100.0 ng/mL for 2-methylfuran. The obtained RSD values were less than 4% for all analytes detected proving the precision and robustness of the method (Table 2). No signals were found for any analyte at their respective retention times, proving the specificity of this method for analysis of concerned analytes. The LOD/LOQ values were 0.062 ng/mL/0.20 ng/mL for furan, 0.091 ng/mL/0.32 ng/mL for furfural, and 0.056 ng/mL/0.18 ng/mL for 2-methylfuran, respectively. The LOD of both furan and 2-methylfuran by isotope dilution method was 0.05 ng/g (Becalski et al. 2010). The LOD of furan was 0.2 μg/kg HS-GC/MS and 0.15 μg/kg by purge and trap method, respectively (Lachenmeier et al. 2009). Hu et al. (2016) have detected furan, 2-methylfuran, and 2-pentylfuran in fruit juices and attained detection limits of 0.056 ng/mL, 0.042 ng/mL, and 0.23 ng/mL respectively. The current study has also provided sensitive values of LOD and LOQ for all analytes. The recovery of each analyte after SPME performance from different soy sauce samples has been shown in Table 3. All compounds with different spiking levels have given recoveries between 94 and 105%. It indicates high accuracy and reproducibility of the current method. Three analytes would simultaneously extracted and separated on HP-5MS column (30 m * 0.25 mm * 0.25 μm) in less than 7.5 min. It has indicated that this method is valid and highly efficient, hence can be used for simultaneous and accurate analysis of these analytes from different soy sauce samples.

Table 2.

The determined statistical data of all analytes

Compounds Calibration curves/method linearity RSD (% n = 3) LOD (ng/mL) LOQ (ng/mL)
Linear range (ng/mL) R2 1.0 ng/mL 5 ng/mL 50 ng/mL
Furan 1.02–100.02 0.9999 3.56 0.70 1.63 0.062 0.20
Furfural 1.01–100.01 0.9997 3.60 1.20 2.00 0.091 0.32
2-Methylfuran 1.00–100.0 0.9995 2.17 0.90 2.3 0.056 0.18
Open in a new tab

Table 3.

Percent recoveries data of all analytes at different concentration levels

Compounds Percent recoveries at different concentration levels of analytes by spiking blank sample (%)
1.0 ng/mL 5.0 ng/mL 50.0 ng/mL
Furan 98 97 99
Furfural 99 100 96
2 Methylfuran 105 99 94
Open in a new tab

Analysis of furan and its derivatives in different soy sauce samples

Furan, furfural and 2-methylfuran have given significantly different concentration levels at (p < 0.05) in six different types of commercially available soy sauces. The concentration levels were ranged from 88.22 to 179.17 ng/mL, 87.88 to 119.71 ng/mL and 28.44 to 88.96 for furan, furfural and 2-methylfuran from six soy sauce samples (Table 4). The highest concentrations of furan were determined in A3 brand of soy sauce (p < 0.05), while A2 brand has given highest concentrations of furfural and 2-methylfuran at p < 0.05. It can be analyzed that the concentration of contaminants formation were greatly dependent on of soy sauce constituents and their fermentation conditions. A number of flavor enhancers had increased concentration levels of furan and its derivatives along with increasing the taste attributes of seasonings.

Table 4.

The concentration of all analytes determined in six commercially available soy sauces

Numbers Description Furan (ng/mL) Furfural (ng/mL) 2-Methylfuran (ng/mL)
A1 Water, edible salt, non-GM skimmed soy bean. Wheat flour, yeast extract, sodium glutamate, disodium 5-nucleotide, potassium sorbate, sucralase 111.46c 87.88f 74.58b
A2 Non-transgenic soybean, edible salt, wheat, sodium amino acid, wheat flour, 5-inosine disodium, caramel colour, sodium benzoate, sucralase 172.92e 119.71a 88.96a
A3 Water, non-GM skim soybean, non GM soybean, edible salt, caramel colored wheat, wheat flour, sodium glutamate, disodium 5-nucleotide, disodium 5-inosine, sucrose, xanthan gum, sodium benzoate 179.17f 98.02e 48.57d
A4 Non-GM defatted soybean, wheat, corn, salt, sucrose 88.22a 112.36b 28.44f
A5 Water, non-GM skimmed soy, exo soy edible caramel, wheat, sodium glutamate disodium 5-nucleotide 154.81d 109.29c 56.34c
A6 Organic defatted soybean, organic wheat, salt, yeast 99.49b 104.92d 38.32e
Open in a new tab

Data in the same column differs significantly (p < 0.05) by Duncan multiple test range

Effect of various food additives in different soy sauce samples

This study has focused on inhibition strategy of formed furan and its derivatives in different soy sauces by adding different reducing agents and natural antioxidants as food additives. A previously conducted study has given evidence that furan formation can be effected by addition of food additives (Kim et al. 2015). Hence, the present study was conducted on detection of furan and its derivatives in commercially available soy sauces and their inhibition by addition of antioxidants and reducing agents as food additives and compared their trapping efficiency of which can be used as a best trapping agent. These all additives were listed in MFDS database (2014).

The effect of iron sulfate (0.1 mg/mL) addition in six brands of soy sauce has given a tremendously increment in formation of furan, furfural and 2-methylfuran. The percent increase in concentrations from all soy sauce brands were ranged from 114 to 149.24%, 114.41 to 152.71% and 130.92 to 194.96% for furan, furfural and 2-methylfuran respectively, as compared to controls (Fig. 2). It might be an expectation that the tremendous increase in concentration of all analytes may be due to the fact that iron increased strecker reactions in the amino acids pathway leading to furan formation along with its derivatives (Locas and Yaylayan 2004). Another fact could be a decisive effect of iron sulfate during oxidation reactions during development of furan in sugar and lipids. In previous study by Kim et al. (2015), the same results were found and it was evidenced that ferric ions would have effect on lipid oxidation, influencing furan formation in model systems. Soy sauce contains a handsome amount of lipids in them due to contents of soybean; hence the lipid oxidation is expected in this scenario. The reduction caused by sodium sulfite has given reduction till 35.75 ng/mL, 24.65 ng/mL and 32.97 ng/mL for furan, furfural and 2-methylfuran from controls with values as 112.93 ng/mL, 88.09 ng/mL and 74.50 ng/mL respectively, after analyzing all samples (Fig. 2). However, the reduction activity observed by sodium sulfite was seemed not much effective. The reductions caused by calcium and magnesium have shown more effectiveness because amounts of furan and derivatives have decreased to significant levels and it was shown that furan, furfural and 2-methylfuran were decreased upto 10.52 ng/mL, 9.62 ng/mL and 9.75 ng/mL, respectively as compared to controls (controls: 112.93 ng/mL, 88.09 ng/mL, 28.20 ng/mL) upto least reduction levels by addition of calcium. Similarly, magnesium has also shown least reduction levels upto 19.38 ng/mL, 16.37 ng/mL and 18.33 ng/mL for furan, furfural and 2-methylfuran respectively, after analyzing all samples and controls (controls: 112.93 ng/mL, 88.09 ng/mL, 88.19 ng/mL) (Fig. 2). After examining the reduction tendency, it can be suggested that chelate effects of calcium and magnesium would be a reason of reduction of furanoic compounds, because of binding effects of these metal ions with molecules and ions in solutions and also the reducing effects of metal ions.

Fig. 2.

Fig. 2

Open in a new tab

Reduction of furan, furfural and 2-methylfuran by addition of different additives in six soy sauce samples with comparison of trapping efficiency. Data are presented as mean ± SD. Symbols in fig represents as Fe (ferric sulphate), Na (sodium sulphate), Ca (calcium sulphate), Mg (magnesium sulphate), AA (ascorbic acid), EGCG (epi galactocatechin), EC (epicatechin), Kf (kempferol)

When ascorbic acid was added as additive in all brands of soy sauce, it has triggered the formation of furanoic compounds instead of reducing. The amounts of furan, furfural and 2-methylfuran were increased upto 167 ng/mL, 139.89 ng/mL and 98 ng/mL, respectively, from all analyzed samples as compared to their controls (controls: 155.24 ng/mL, 112.80 ng/mL, 88.19 ng/mL) (Fig. 2). Hence, it can be expected because the previous studies have indicated that ascorbic acid could be transformed into 3-deoxy-pentosulose (DP) and 2-deoxy-alsotetrose. Since, this 2-deoxy-aldotetrose could also be produced by decomposition of sugars, which can lead to formation of furanoic compounds (Locas and Yaylayan 2004). The addition of EGCG, EC and kempferol has also given significant reduction levels of all analytes as natural antioxidants. However, the reduction effects of EC and kempferol are more prevalent as compared to EGCG in our study (Fig. 2). The trapping efficiency of these natural polyphenols has tremendously provided good reduction. It would be expected as natural polyphenols have dicarbonyl trapping efficiency and can scavenge free radicals (Hu et al. 2018). These are most good inhibitors because they have proven as antimutagenic and anticarcinogenic (Kumar et al. 2012).

Conclusion

This study has simultaneously determined the concentration of furan, furfural and 2-methylfuran in commercially available soy sauce by HS-SPME GC-TQ/MS method. The amount of furan and furfural formed in all samples were more than 2-methylfuran. Furthermore, some food additives including metal ions, organic acid and natural antioxidants were added by simulating sterilization conditions and their relative inhibition and trapping efficiency was determined and it has concluded that calcium sulphate, magnesium sulphate, epicatichen and kempferol can give more efficient inhibition than other food additives.

Acknowledgements

This work is supported by the National Key R&D Program of China (No. 2017YFC1600401), National Natural Science Foundation of China (Nos. 31671961 and 31701727), Key Projects of Guangdong Natural Science Foundation (No. 2017A030311021), Key Project of Guangzhou S&T Program (No. 201904020005), YangFan Innovative and Enterpreneurial Research Team Project (2014YT02S029) and the 973 program (No. 2012CB720801).

Compliance with Ethical Standards

Conflict of interest

The authors declare no conflict of interest.

Ethical approval

This research does not contain human or animal subjects.

Informed consent

Not applicable in present study.

Footnotes

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Contributor Information

Bing Li, Email: bli@scut.edu.cn.

Lin Li, Email: felinli@scut.edu.cn.

References

  1. Anese M, Manzocco L, Calligaris S, Nicoli MC. Industrially applicable strategies for mitigating acrylamide, furan, and 5-hydroxymethylfurfural in food. J Agric Food Chem. 2013;61(43):10209–10214. doi: 10.1021/jf305085r. [DOI] [PubMed] [Google Scholar]
  2. Altaki MS, Santos FJ, Galceran MT. Occurrence of furan in coffee from Spanish market: contribution of brewing and roasting. Food Chem. 2011;126:1527–1532. doi: 10.1016/j.foodchem.2010.11.134. [DOI] [PubMed] [Google Scholar]
  3. Bolger MP, Tao SS, Dinovi M. Hazards of dietary furan. In: Richard DRL, Stadler H, editors. Process-induced food toxicants. Hoboken: Wiley; 2009. pp. 117–133. [Google Scholar]
  4. Becalski A, Hayward S, Krakalovich T, Pelletier L, Roscoe V, Vavasour E. Development of an analytical method and survey of foods for furan, 2-methylfuran and 3-methylfuran with estimated exposure. Food Addit Contam. 2010;27:764–775. doi: 10.1080/19440040903473332. [DOI] [PubMed] [Google Scholar]
  5. Condurso C, Cincotta F, Verzera A. Determination of furan and furan derivatives in baby food. Food Chem. 2018;250:155–161. doi: 10.1016/j.foodchem.2017.12.091. [DOI] [PubMed] [Google Scholar]
  6. Crews C, Castle L. A review of the occurrence, formation and analysis of furan in heat-processed foods. Trends Food Sci Technol. 2007;18(7):365–372. doi: 10.1016/j.tifs.2007.03.006. [DOI] [Google Scholar]
  7. EFSA (European Food Safety Authority Journal) Consideration of 40 furan-substituted aliphatic hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids and related esters, sulfides, disulfides and ethers evaluated by JECFA at the 65th meeting and reevaluated at the 69th meeting. Eur Food Saf Auth J. 2011;9(10):2315. [Google Scholar]
  8. Feng YZ, Cui C, Zhao HF, Gao XL, Zhao MM, Sun WZ. Effect of koji fermentation on generation of volatile compounds in soy sauce production. Int J Food Sci Technol. 2013;48(3):609–619. doi: 10.1111/ijfs.12006. [DOI] [Google Scholar]
  9. Gramza A, Korczak J, Amarowicz R. Tea polyphenols—their antioxidant properties and biological activity—a review. Pol J Food Nutr Sci. 2005;14/55(3):219–235. [Google Scholar]
  10. Hu G, Yan ZA, Marta HA, Tatiana KA, Suqin S. An efficient method for the simultaneous determination of furan, 2-methylfuran and 2-pentylfuran in fruit juices by headspace solid phase microextraction and gas chromatography–flame ionisation detector. Food Chem. 2016;192:9–14. doi: 10.1016/j.foodchem.2015.06.100. [DOI] [PubMed] [Google Scholar]
  11. Hoang NX, Ferng S, Ting C, Huang W, Chiou RY, H CK. Optimizing the initial moromi fermentation conditions to improve the quality of soy sauce. Lebensmittel-Wissenschaft und Technologie Food Sci Technol. 2016;74:242–250. doi: 10.1016/j.lwt.2016.07.049. [DOI] [Google Scholar]
  12. Hu G, Liua H, Zhua Y, Hernandeza M, Koutchmaa T, Shaoa S. Suppression of the formation of furan by antioxidants during UV-C light treatment of sugar solutions and apple cider. Food Chem. 2018;269:342–346. doi: 10.1016/j.foodchem.2018.07.009. [DOI] [PubMed] [Google Scholar]
  13. International Agency for Research on Cancer (1995) IARC Monographs on the evaluation of carcinogenic risks to humans: dry cleaning, some chlorinated solvents and other industrial chemicals, vol 63. Lyon, France, pp 393–407 [PMC free article] [PubMed]
  14. Januszkiewicz J, Sabik H, Azarnia S, Lee B. Optimization of headspace solid-phase microextraction for the analysis of specific flavors in enzyme modified and natural Cheddar cheese using factorial design and response surface methodology. J Chromatogr A. 2008;1195(1–2):16–24. doi: 10.1016/j.chroma.2008.04.067. [DOI] [PubMed] [Google Scholar]
  15. Kim TK, Kim S, Lee KG. Analysis of furan in heat-processed food consumed in Korean using solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) Food Chem. 2010;123(4):1328–1333. doi: 10.1016/j.foodchem.2010.06.015. [DOI] [Google Scholar]
  16. Kim JS, Lee YS. A study of chemical characteristics of soy sauce and mixed soy sauce: chemical characteristics of soy sauce. Eur Food Res Technol. 2008;227(3):933–944. doi: 10.1007/s00217-007-0808-4. [DOI] [Google Scholar]
  17. Kumar S, Singh N, Shweta A. Green tea polyphenols: versatile cosmetic ingredient. Int J Adv Res Pharm Bio Sci. 2012;1(3):348–362. [Google Scholar]
  18. Kim TK, Lee YK, Kim S, Park YS, Lee KG. Furan in commercially processed foods: four-year field monitoring and risk assessment study in Korea. J Toxicol Environ Health Part A Curr Issues. 2009;72(21–22):1304–1310. doi: 10.1080/15287390903212378. [DOI] [PubMed] [Google Scholar]
  19. Kim MY, Her JY, Kim MK, Lee KG. Formation and reduction of furan in a soy sauce model system. Food Chem. 2015;189:114–119. doi: 10.1016/j.foodchem.2015.02.015. [DOI] [PubMed] [Google Scholar]
  20. Lee JS, Rho SJ, Kim YW, Lee KW, Lee HG. Evaluation of biological activities of the short-term fermented soybean extract. Food Sci Biotechnol. 2013;22(4):973–978. doi: 10.1007/s10068-013-0172-z. [DOI] [Google Scholar]
  21. Locas CP, Yaylayan VA. Origin and mechanistic pathways of formation of the parent furan—a food toxicant. J Agric Food Chem. 2004;52(22):6830–6836. doi: 10.1021/jf0490403. [DOI] [PubMed] [Google Scholar]
  22. Limacher A, Kerler J, Davidek T, Schmalzried F, Blank I. Formation of furan and methylfuran by Maillard-type reactions in model systems and food. J Agric Food Chem. 2008;56(10):3639–3647. doi: 10.1021/jf800268t. [DOI] [PubMed] [Google Scholar]
  23. Lachenmeier DW, Reusch H, Kuballa T. Risk assessment of furan in commercially jarred baby foods, including insights into its occurrence and formation in freshly home-cooked foods for infants and young children. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2009;26:776–785. doi: 10.1080/02652030802714018. [DOI] [PubMed] [Google Scholar]
  24. Mariotti M, Granby K, Fromberg A, Risum J, Agosin E, Pedreschi F. Furan occurrence in starchy food model systems processed at high temperatures: effect of ascorbic acid and heating conditions. J Agric Food Chem. 2012;60(40):10162–10169. doi: 10.1021/jf3022699. [DOI] [PubMed] [Google Scholar]
  25. MFDS-a (Ministry of Food and Drug Safety). Food additives code, 2014. https://www.mfds.go.kr/fa/ebook/egongjeon_intro.jsp. Accessed 16 Dec 2013.
  26. Nie S, Huang J, Hu J, Zhang Y, Wang S, Li C. Effect of pH, temperature and heating time on the formation of furan in sugar-glycine model systems. Food Sci Hum Wellness. 2013;2:87–92. doi: 10.1016/j.fshw.2013.05.001. [DOI] [Google Scholar]
  27. Okaru AO, Lachenmeier DW. The food and beverage occurrence of furfuryl alcohol and myrcene-two emerging potential human carcinogens? Toxics. 2017;5(1):9. doi: 10.3390/toxics5010009. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Petisca C (2014) Furanic compounds in food products: assessment and mitigation strategies. https://repositorio-aberto.up.pt/bitstream/10216/73765/2/60075.pdf. Accessed 27 June 2016.
  29. Rufian-Henares JA, Delgado-Andrade C, Morales FJ. Assessing the Maillard reaction development during the toasting process of common flours employed by the cereal products industry. Food Chem. 2009;114(1):93–99. doi: 10.1016/j.foodchem.2008.09.021. [DOI] [Google Scholar]
  30. Sarafraz-Yazdi A, Abbasian M, Amiri A. Determination of furan in food samples using two solid phase microextraction fibers based on sot-gel technique with gas chromatography-flame ionisation detector. Food Chem. 2012;131:698–704. doi: 10.1016/j.foodchem.2011.09.019. [DOI] [Google Scholar]
  31. Verzera A, Condurso C, Romeo V, Tripodi G, Ziino M. Solid-phase microextraction coupled to fast gas chromatography for the determination of migrants from polystyrene-packaging materials into yoghurt. Food Anal Methods. 2010;3(2):80–84. doi: 10.1007/s12161-009-9088-x. [DOI] [Google Scholar]
  32. Wu SJ, Wang ET, Yuan Y. Detection of furan levels in select Chinese foods by solid phase microextraction–gas chromatography/mass spectrometry method and dietary exposure estimation of furan in the Chinese population. Food Chem Toxicol. 2014;64:34–40. doi: 10.1016/j.fct.2013.12.006. [DOI] [PubMed] [Google Scholar]
  33. Zoller O, Sager F, Reinhard H. Furan in food: headspace method and product survey. Food Addit Contam. 2007;24:91–107. doi: 10.1080/02652030701447389. [DOI] [PubMed] [Google Scholar]
  34. Zhang YF, Tao WY. Flavor and taste compounds analysis in Chinese solid fermented soy sauce. Afr J Biotechnol. 2009;8(4):673–681. [Google Scholar]
  35. Zhu F, Cai YZ, Keb J, Corkea H. 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. 2009;89:1674–1681. doi: 10.1002/jsfa.3640. [DOI] [Google Scholar]

Articles from Journal of Food Science and Technology are provided here courtesy of Springer

RESOURCES