Polycyclic aromatic hydrocarbons in beverage and dairy products in South Korea: a risk characterization using the total diet study

Abstract

Polycyclic aromatic hydrocarbons (PAHs) were analyzed using gas chromatography–mass spectrometry in 115 dairy products and beverages, including alcoholic, grain, carbonated, and functional drinks; fruit and vegetable juices; coffee; and tea, purchased from 10 local city markets in South Korea. The sample groups were divided into non-fatty and fatty groups, pretreated with the ultrasound-assisted extraction method and saponification method, respectively. The limit of detection, limit of quantification, and accuracy were 0.038–0.185 μg/kg, 0.114–0.560 μg/kg, and 87.64–112.25%, respectively. The measurement uncertainty was ≤ 6.38% for eight PAHs (PAH8). PAH8 was detected in 41 of the 115 samples, ranging from 0.041 to 7.793 µg/kg. The risk assessment revealed that the margin of exposure for PAH8 ranged from 3.60 × 10⁴ to 7.84 × 10¹¹ in the mean intake groups and from 3.60 × 10⁴ to 5.33 × 10¹¹ in the P97.5 intake groups.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-021-00927-7.

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds containing two or more aromatic rings. PAHs include more than 100 hazardous chemicals from food and the environment (Nagpal, 1993). Unavoidable interactions with the atmosphere, water, and soil result in the migration of PAHs into food, and therefore the main source of exposure to PAHs is food (Hodson, 2017). PAHs are frequently identified in foods, including processed meats and fish, lipids, smoked products, and fatty foods, with a high priority for food safety (Kammann et al., 2017).

Research on PAHs in milk, coffee, tea, beverages, and alcoholic drinks is scant relative to other major food items. PAHs in these foods have lower detection rates or are present in lower quantities than in other meat or smoked products. However, the toxicity of PAHs may be a concern because of the high intake quantity of these foods (Locatelli et al., 2014). According to a report by the European Food Safety Authority (EFSA) (EFSA, 2008), the consumption of coffee, tea, and alcoholic beverages is higher than that of meats, oils, and fish in 16 European countries. PAHs may arise in tea and coffee because of their heat processing, such as roasting, drying, and smoking (Tfouni et al., 2013). The dietary intake of PAHs is high for milk and milk products, and the production of PAHs by heat treatment during processing has been described (Shariatifar et al., 2020). In cereals, fruits, and vegetables, which are the raw materials for drinks and alcoholic beverages, trace quantities of PAHs are deposited in the waxy surface layer of fruits and vegetables or in the fat components of seeds or cereals that may migrate into drinks or alcoholic beverages (Arvanaghi et al., 2017).

PAHs in cells can be cytotoxic and can cause mutations and carcinoma. Their carcinogenicity varies based on the number and structure of the aromatic rings (Amirdivani et al., 2019). Benzo[a]pyrene (BaP) has been designated by the International Agency for Research on Cancer (IARC) in human carcinogenic group 1 and dibenzo[a,h]anthracene (DahA) in human carcinogenic group 2A. Benzo[a]anthracene (BaA), chrysene (Chry), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), and indeno[1,2,3-c,d]pyrene (IcdP) are in group 2B and are possible human carcinogens (IARC, 2010). The European Commission (EC) proposed BaP as a marker for the carcinogenicity of PAHs in food (Commission, 2006). However the EFSA suggested that using four PAHs (BaA, Chry, BbF, and BaP, collectively designated as PAH4) or eight substances (BaA, Chry, BbF, BkF, BaP, IcdP, DahA, and benzo[ghi]perylene (BghiP), collectively designated as PAH8) instead of BaP alone is a more suitable predictor of PAHs in food (EFSA ECP, 2008). The European Union (EU) established a regulation for the maximum levels of PAH4 in some food matrices, including oil and fat (10 µg/kg), smoked meat (12 µg/kg), and infant formula (1 µg/kg) (European Commission, 2011). However, regulations have not been established for coffee and tea drinks, vegetable juices, alcoholic beverages, and other consumed fluids.

Total diet studies (TDS) represent one of the most cost-effective methods for monitoring and assessing the risks of dietary exposure to harmful substances. Many countries, France (Sirot et al., 2019) and Sub-Saharan Africa (Ingenbleek et al., 2019), have conducted TDS on PAHs. In TDS for PAHs, the sample includes raw materials and food in a “table-ready” shape, which is prepared with the use of a recipe just before ingestion. A study investigating beverage intake by age in the United States showed that the intake of milk in participants 2 to 19 years of age was higher than that of other age groups, with the highest intake rate being 60 years or older for coffee and tea, 12–39 years for soda, 2–11 years for vegetable drinks, and 12–19 years for sports drinks (Bleich et al., 2018). Young individuals (18–30 years of age) have higher drinking rates than older individuals (60–80 years of age). Risk assessment studies on PAHs in beverages and dairy products, considering age-dependent intake variables, are limited.

The toxicity of PAHs can be calculated using toxic equivalent factors (TEF) relative to BaP, and the overall quantity of the individual PAH content is determined as the toxic equivalence (TEQ) (Nisbet and LaGoy, 1992). However, the EFSA recently stated that the TEQ strategy is only appropriate for substances of the same toxicological mechanism, such as polychlorinated dibenzo-p-dioxins and -dibenzofurans (EFSA, 2008). Since some PAHs cause tumors by mechanisms other than their recognized action of binding to DNA and causing a carcinogenic mutation, a toxicological value from mixture of PAHs is recommended to assess the risk of PAHs by the EFSA. To the best of our understanding, however, few studies have been conducted to determine the risk of PAHs using a specific toxicological value rather than a TEQ method value. The EFSA used the margin of exposure (MOE) based on the benchmark dose lower confidence limit for a 10% increase in the number of tumor-bearing animals compared to control animals (BMDL₁₀) to determine the risk assessment of PAHs (EFSA, 2008).

The present study evaluated the PAH8 content of dairy products and drinks, including alcoholic, fruit, vegetable, cereal, and carbonated beverages; coffee; and tea, using TDS data derived from the quantity of PAH exposure in South Korea. A risk assessment was also performed by measuring the exposure to PAH8 through food consumed daily using TEQ and MOE.

Materials and methods

Reagents and materials

Two internal standards, chrysene-d12 (Chry-d₁₂) and benzo[a]pyrene-d12 (BaP-d₁₂), and PAH8, a mixture of BaA, Chry, BbF, BkF, BaP, IcdP, DahA, and BghiP, were purchased from Supelco (Bellefonte, PA, USA). The two internal standards and PAH8 standard solutions were prepared at 100 μg/mL and 0.5–20 μg/mL in dichloromethane (DCM), respectively, and were stored at -4 °C. Anhydrous sodium sulfate (NA₂SO₄) for dehydration was obtained from Yakuri Pure Chemicals (Kyoto, Japan). Filter paper was obtained from Whatman (Maidstone, Kent, UK). Potassium hydroxide (KOH) for alkali saponification was purchased from Showa Denko (Tokyo, Japan). The dichloromethane, ethanol, and n-hexane solvents were obtained from Burdick & Jackson (Muskegon, MI, USA). For purification, Sep-Pak bond elute silica cartridges used for solid-phase extraction were purchased from Agilent Technologies (Santa Clara, CA, USA).

Samples

Samples (n = 115) of the aforementioned dairy products, beverages, coffee, and tea were obtained from 21 supermarkets in 10 different cities throughout South Korea. Local market allocation was performed based on the number of resident registration data from the Ministry of Public Administration and Security of South Korea in 2017. A sample list was prepared by including food recipes corresponding to an intake rate of 95% and a consumer rate of 1% or more using data from the 2010–2016 National Health and Nutrition Examination Survey (KNHNES) of South Korea.

Samples purchased from the 21 local markets were delivered to Chung-Ang University (Gyeonggi-do, Republic of Korea) on the same day to inspect the samples. Each sample was collected in the same amount, and the raw material was pooled. The pooled samples were cleaned, the non-edible components were removed, and the samples were cooked according to the selected recipe. Tap water was used for cooking, reflecting the preparation in a typical household. After cooking, the samples were homogenized, and quantities exceeding 100 g were sealed with para-film in a polyethylene tube and delivered to Korea University (Seoul, Republic of Korea)for analysis in the frozen state (− 20 °C).

Selected samples were used without cooking (Ori) or processing via six different methods: boiling, stir-frying, grilling, boiling after stir-frying, air frying, and adding boiled water. The various recipes were followed as described by recipe books focused on Korean cuisine (Kim et al., 2020). For boiling, the samples were cooked in boiling water for 6–15 min. For stir-frying, the samples were placed in a preheated pan (170 °C) and cooked with stirring for 2–10 min. For grilling, the samples were cooked for 2–10 min in a frying pan and preheated to 170 °C. For air frying, the samples were fried at 180 °C using an air frying unit (Philips, Amsterdam, Netherlands). In the preparation involving the addition of boiled water, boiling water was added to a standard amount of each sample according to the recipe on the sample package. For the tea infusion process, the tea bag was immersed in a defined volume of boiling water as described on the sample packet and was separated for 2–3 min after leaching.

Sample preparation

Analytical methods of PAH8 in food were used with a previously described minor change (Lee et al., 2018b). The saponification procedure was used in samples with a high fat content. Ten grams of sample was weighed in a round-bottomed flask. One hundred milliliters of 1 M potassium hydroxide solution in ethanol was added to 1 mL of internal standard solution (100 μg/kg of chrysene-d12 and benzo[a]pyrene-d12). For saponification, each sample was heated at 80 °C for 3 h in a water bath and cooled with cold water. Solids were removed by passage through filter paper into a separating funnel. Each flask was washed with 50 mL of n-hexane, ethanol:n-hexane (1:1, v/v), and distilled water and collected in a funnel. The mixture was shaken thoroughly for 10 min using an orbital funnel shaker (Changshin Science, Seoul, Republic of Korea) at 300 rpm to collect the organic phase. This solution was subjected to two liquid–liquid extractions using 50 mL of n-hexane. One hundred milliliters of purified water was added and shaken. The water layer was discarded, and the process was repeated. The accumulated n-hexane layer was allowed to be clearly separated from the water layer. The transparent upper hexane phase was dehydrated with anhydrous sodium sulfate (Na₂SO₄) (> 99% pure, Yakuri Pure Chemicals, Kyoto, Japan) after discarding the water layer and then condensing at 40 °C to a final volume of 2 mL using a rotary evaporator (EYELA, Tokyo, Japan). The concentrate was filtered through Sep-Pak silica cartridges activated with 10 mL of DCM and eluted with 20 mL of n-hexane using 5 mL of n-hexane and 15 mL of n-hexane:DCM mixture (3:1, v/v). The eluent was concentrated at 40 °C with a stream of nitrogen gas, dissolved in 1 mL DCM, and filtered through a 0.45-μm polytetrafluoroethylene membrane filter for GC/MS analysis.

For samples with a lower fat content, an ultrasound-assisted extraction method was used for the pretreatment of the GC/MS samples. The samples (10 g) were individually weighed in a flask containing 50 mL of n-hexane and 1 mL of the internal standard mixture (100 μg/kg of chrysene-d12 and benzo[a]pyrene-d12), sealed with a cap, and sonicated for 30 min. Fifty milliliters of n-hexane was added, and the extraction was repeated twice. Sodium sulfate anhydrous was used for the dehydration of the n-hexane extracts, and the next step for condensing the dehydrated n-hexane extracts was the same as the procedure for the pretreatment of the high-fat samples described above.

GC/MS

A model 7890B gas chromatograph (Agilent Technologies, Santa Clara, CA, USA) equipped with an HP-5MS Ultra Inert column (30 m × 0.25 mm × 0.25 μm, Agilent Technologies) and 5977B mass spectrometer (Agilent Technologies) were used for analyses of the PAHs. Helium was used as the carrier gas at a flow rate of 1.0 mL/min. The injection was conducted in the splitless mode at 320 °C. The programmed temperature sequence of the oven was 80 °C for 1 min, increased to 220 °C (20 °C/min) and maintained for 10 min, and increased to 280 °C (2 °C/min) and maintained for 10 min. MS was performed at 70 eV in the electron impact mode using selected ion monitoring. The selected target ions (m/z) for the eight PAHs and internal standards were as follows: BaA (228), Chry (228), Chry-d12 (240), BbF (252), BkF (252), BaP(252), BaP-d12 (264), IcdP (276), DahA (278), and BghiP (276).

Validation

For method validation and analytical quality assurance, blank samples of milk for the ultrasound-assisted extraction method and beef for the saponification method were spiked with PAH8 at different concentrations and two internal standards (chry-d₁₂ and BaP-d₁₂) of 100 μg/kg (Supplementary Fig. 1). The linearity (R²), limit of detection (LOD), limit of quantification (LOQ), recovery, and precision test followed the Association of Official Agricultural Chemists and International Conference on Harmonization guidelines (Guideline IHT, 2005). For calibration curves, six different PAH8 concentrations (0.5, 1, 2, 5, 10, and 20 μg/kg) were used with two internal standards. The LOD and LOQ values were defined according to 3.3 and 10 to the (standard deviation)/(slope of the calibration curve), respectively. Accuracy and precision were obtained using three different concentrations (5, 10, and 20 μg/kg) with two internal standards, with five repetitions for intraday and interday analyses.

Uncertainty of PAH8 analysis

The assessment of uncertainty is a quantitative measurement of the reliability of measurements. The uncertainty for the PAH8 study was calculated on the basis of the Guide to the Expression of Measurement Uncertainty (GUM) and the EURACHEM/CITAC Guide (Ramsey and Ellison, 2007). First, the uncertainty was determined when 10 ppb PAH8 mixtures of standards and 100 ppb internal standards were spiked in the milk and beef samples. Next, a fish bone diagram was created to calculate the measurement uncertainty. The diagram illustrates the factors of the PAH8 uncertainty of the entire experiment (Supplementary Fig. 2). Type A (statistical evaluation) and B (other information) were used to identify these factors. The type A approach was estimated where statistics and repeated measurements were used. The type B approach was used where the calibration certificate report was available. According to the EURACHEM/CITAC method, a coverage factor (k = 2) was applied at a confidence level of 95% when the degree of freedom was ≥ 10 (Ramsey and Ellison, 2007). The combined standard uncertainty was obtained from the standard uncertainty for each factor through types A and B. The expanded uncertainty was finally obtained by multiplying the coverage factor by the combined standard uncertainty. The result of uncertainty was expressed as the measured concentration ± the expanded uncertainty. According to the International Organization for Standardization/International Electrotechnical Commission Joint Technical Committee (ISO/IEC JTC) (Codex, 2004), when the concentration of a substance is ≤ 100 ppb, the expanded uncertainty should be < 44%.

Ingestion of PAH and risk assessment

The risk assessment was performed as previously described (Lee et al., 2018b; Rocha et al., 2020). Because each PAH has different toxicities, TEF values, which represent the relative carcinogenic potency of each PAH, were used (Nisbet and LaGoy, 1992). The sum of toxic equivalent quantity (ΣTEQ_BaP) was estimated by adopting TEF values of PAH8 and calculated as follows (WHO and FAO, 2003):

$$\mathrm{\Sigma }\text{TEQBaP}=\sum _{\text{i}=1}^{\text{n}}\text{Ci}\times \text{TEFi}$$ 1

where $\text{Ci}$ is the concentration of the PAH8 toxic value of the food sample and $\text{TEFi}$ is the TEF of PAH8 congener_i in the food sample. The TEQ was calculated for the total PAH8 level, converting it to BaP using TEF values in food samples.

The calculations for the intake of each age group exposure to food samples were performed following the applicative guidelines (EU, 2015):

$$\text{Daily}\text{intake}=\sum _{\text{i}=1}^{\text{n}}\frac{\text{CFi}\times \text{IRi}}{\text{BW}}$$ 2

where CF_i is the total TEQ_B(a)P value of PAH8 in the food sample (μg/kg), IR_i is the daily ingestion rate of the food sample for each age group from the KNHANES, and BW is the average body weight (kg) of the KNHNES subjects.

To assess the risk, MOE was used (Agency, 2005). The MOE was calculated using the BMDL₁₀ for PAH8 divided by the daily intake value as follows:

$$\text{MOE}=\frac{\text{BMDL10}}{\text{Daily}\text{intake}}$$ 3

where the BMDL₁₀ value for PAH8 is 0.49 mg/kg BW/day from a reference by (EFSA ECP, 2008). An MOE > 10⁵ negligible concern, 10⁴–10⁵ low concern, and < 10⁴ possible concern (EFSA Panel on Dietetic Products et al., 2016).

Results and discussion

Method validation

A chromatogram of PAH8 and the two internal standards is shown in Supplementary Fig. 1. To validate the PAH8 method, experiments were conducted with a milk sample (ultrasound-assisted extraction method) and a beef sample (saponification method). Beef and milk were used as representative samples for a high fat matrix and a low fat or liquid matrix, respectively. Table 1 shows the verification results for linearity, LOD, LOQ, accuracy, and precision. Method validation in the milk and beef matrices revealed that the linearity (R²) ranged from 0.992 to 0.999 in the range of 0.5–20 μg/kg. The LOD ranged from 0.038 to 0.185 μg/kg, and the LOQ ranged from 0.114 to 0.560 μg/kg. Accuracy and precision were tested through intraday and interday tests. The intraday (day 1–3) accuracy rates of PAH8 ranged from 88.21 to 112.3%, and the precision was < 9.42% relative standard deviation (RSD). The accuracy of the interday results was 87.64 to 105.4%, and the precision was < 10.2%. The EC regulations (European Commission, 2011) specify an LOD and LOQ using two pretreatment procedures as < 0.3 μg/kg and < 0.9 μg/kg, respectively, and intra- and interday PAH8 precisions of 50–120%. The EC specifications indicated that our results are valid. The analysis findings were comparable to the results of our previous research using the same pretreatment approach, with an LOD of 0.04–0.11 μg/kg and LOQ of 0.06–0.36 μg/kg in the less fatty category and an LOD of 0.04–0.24 μg/kg and LOQ of 0.12–0.75 μg/kg in the fatty group (Lee et al., 2018b). Therefore, the PAH8 analysis using GC/MS was satisfactory with the pretreatment procedure applied to the less fatty and fatty samples used in this study.

Table 1.

Results of method validation and uncertainties for eight polycyclic aromatic hydrocarbons (PAH8) in beef and milk matrices

Matrix	Compounds	R2	LODa (μg/kg)	LOQ (μg/kg)	Uncertainties			Intraday (n = 5)		Interday (n = 5)
					Ucb (μg/kg)	Concentration ± expanded uncertainty (μg/kg)	Uncertainty/Result (%)	Accuracy (%)	Precision (% RSD)	Accuracy (%)	Precision (% RSDc)
Beef	BaAd	0.9999	0.086	0.261	0.21	10.05 ± 0.42	4.18	98.84–101.5	0.43–2.91	99.46–100.5	0.15–1.54
	Chry	0.9999	0.185	0.560	0.23	9.80 ± 0.46	4.69	94.00–100.6	0.15–9.42	99.70–100.1	0.09–0.81
	BbF	0.9998	0.171	0.518	0.23	9.86 ± 0.46	4.67	96.40–99.99	0.14–3.10	99.79–101.4	0.23–5.69
	BkF	0.9999	0.055	0.166	0.22	9.83 ± 0.44	4.48	88.21–99.23	0.47–4.91	99.88–100.7	0.13–0.95
	BaP	0.9999	0.117	0.354	0.22	10.11 ± 0.44	4.35	99.34–107.3	0.75–4.91	99.98–100.5	0.11–0.88
	IcdP	0.9996	0.052	0.157	0.21	9.75 ± 0.42	4.31	96.78–101.2	0.15–2.28	98.21–101.1	0.18–0.88
	DahA	0.9999	0.124	0.375	0.21	10.07 ± 0.42	4.17	99.92–101.2	0.07–1.32	99.88–100.9	0.17–0.90
	BghiP	0.9999	0.129	0.390	0.23	9.96 ± 0.45	4.52	99.35–100.9	0.17–1.20	99.53–100.7	0.55–0.94
Milk	BaA	0.9994	0.038	0.114	0.25	9.67 ± 0.49	5.07	93.77–98.16	0.24–1.84	98.96–100.9	0.24–5.42
	Chry	0.9983	0.041	0.123	0.32	10.41 ± 0.64	6.15	102.3–112.3	0.36–1.69	95.72–103.4	1.21–4.15
	BbF	0.9979	0.097	0.295	0.26	9.72 ± 0.51	5.25	92.18–106.3	0.21–1.66	91.79–102.4	0.41–4.44
	BkF	0.9969	0.079	0.238	0.23	10.32 ± 0.47	4.56	100.1–106.1	0.18–2.98	88.90–100.2	0.14–9.24
	BaP	0.9989	0.059	0.179	0.25	10.55 ± 0.51	4.83	103.9–105.3	0.14–1.81	92.65–100.3	0.17–5.48
	IcdP	0.9984	0.107	0.323	0.34	10.66 ± 0.68	6.38	108.3–110.9	0.13–0.36	94.77–100.5	0.84–9.54
	DahA	0.9937	0.140	0.425	0.26	10.81 ± 0.52	4.81	104.4–110.0	0.24–0.53	87.64–103.2	2.18–9.84
	BghiP	0.9928	0.110	0.332	0.29	9.67 ± 0.58	6.00	93.25–94.92	0.35–0.81	99.61–105.4	1.55–10.20

^aThe limit of detection (LOD) and limit of quantitation (LOQ) were calculated as LOD = 3.3σ/s and LOQ = 10σ/s (σ = standard deviation of response (n = 5); s = slope of calibration curve)

^bU_c: combined standard uncertainties

^cRSD: relative standard deviation. If nominal concentration levels are < 100 μg/kg, the typical expanded uncertainty range should be within 44% (ISO, 1999)

^dBaA: benzo[a]anthracene, Chry: chrysene, BbF: benzo[b]fluoranthene, BkF: benzo[k]fluoranthene, BaP: benzo[a]pyrene, DahA: dibenzo[a,h]anthracene, BghiP: benzo[ghi]perylene, IcdP: indeno[1,2,3-c,d]pyrene

Uncertainty of PAH8

To estimate the uncertainty values of PAH8, 10 μg/kg of each standard PAH8 (Supelco, Bellefonte, PA, USA) was added to the beef and milk samples. The uncertainty factors influencing the measurement were determined from the standard solution, internal standard, sample pretreatment, matrix, instrument, and calibration curve. PAH8 uncertainty (measured concentration ± expanded uncertainty, %) (Table 1) were: BaA (9.67 ± 0.49–10.05 ± 0.42 μg/kg, 4.18–5.07%), Chry (9.80 ± 0.46–10.41 ± 0.64 μg/kg, 4.69–6.15%), BbF (9.72 ± 0.51–9.86 ± 0.46 μg/kg, 4.67–5.25%), BkF (9.83 ± 0.44–10.32 ± 0.47 μg/kg, 4.48–4.56%), BaP (10.11 ± 0.44–10.55 ± 0.51 μg/kg, 4.35–4.83%), IcdP (9.75 ± 0.42–10.66 ± 0.68 μg/kg, 4.31–6.38%), DahA (10.07 ± 0.42–10.81 ± 0.52 μg/kg, 4.17–4.81%), and BghiP (9.67 ± 0.58–9.96 ± 0.45 μg/kg, 4.52–6.00%) (confidence level = 95%, coverage factor = 2). The uncertainty values, including the less fatty and fatty groups, were < 44% and so were suitable for ISO/IEC regulation (Codex, 2004).

Monitoring the concentrations of PAHs

The PAHs exceeded the LOD in 41 of the 115 food samples. These included alcoholic drinks (detection seen in 10 of the 27 samples analyzed: n = 10 of 27), fruit and vegetable drinks (n = 3 of 7), grain drinks (n = 2 of 5), carbonated drinks (n = 0 of 5), functional drinks (n = 0 of 2), coffee (n = 3 of 10), tea (n = 1 of 13), and dairy (n = 22 of 46) (Table 2). Unless a comparison is needed, Table 2 does not display the samples with less than LOD in the test samples. The average concentration analyzed three times was used to represent the outcome of sample monitoring. The PAH concentration was calculated as μg/kg (wet weight). The values of $\sum \text{PAH}8$ species and $\sum \text{TEQbap}$ were calculated (Table 2). The average $\sum \text{TEQbap}$ was seen in each drink and dairy product (Fig. 1).

Table 2.

Concentrations of PAH8 detected in beverages and dairy products (unit: μg/kg)

Sample name	Recipe	BaA	Chry	BbF	BkF	BaP	IcdP	DahA	BghiP	ΣPAH8a	ΣTEQbapb
Alcohol drink (detection seen in 10 of the 27 samples analyzed; n = 10 of 27)
Clear rice wine	Grilling	NDc	0.041 ± 0.002	ND	ND	ND	ND	ND	ND	0.041	0.000
Korean bottled beer	Orid	0.039 ± 0.006	0.058 ± 0.006	ND	ND	0.093 ± 0.011	ND	ND	ND	0.190	0.097
Korean canned beer	Ori	ND	0.043 ± 0.003	ND	ND	0.062 ± 0.011	ND	ND	ND	0.105	0.062
Plum wine	Boiling	ND	ND	ND	ND	0.062 ± 0.004	ND	ND	ND	0.062	0.062
Raspberry wine	Ori	ND	0.046 ± 0.002	ND	ND	ND	ND	ND	ND	0.046	0.000
Red wine	Ori	ND	ND	ND	ND	0.062 ± 0.016	ND	ND	ND	0.062	0.062
	Stir-frying	0.048 ± 0.006	0.064 ± 0.005	ND	ND	N.D	ND	ND	ND	0.112	0.005
Rice wine	Ori	0.041 ± 0.004	0.069 ± 0.003	ND	ND	0.115 ± 0.026	ND	ND	ND	0.225	0.120
Vodka	Ori	ND	0.051 ± 0.003	ND	ND	N.D	0.073 ± 0.004	ND	0.275 ± 0.056	0.399	0.011
White wine	Ori	ND	0.048 ± 0.005	ND	ND	0.073 ± 0.022	ND	ND	ND	0.121	0.073
Coffee (n = 3 of 10)
Coffee (bean)	Ori	0.087 ± 0.004	0.167 ± 0.002	0.072 ± 0.004	ND	0.125 ± 0.004	0.117 ± 0.005	ND	0.090 ± .001	0.658	0.155
	Adding boiling water	0.047 ± 0.003	0.068 ± 0.004	ND	ND	0.112 ± 0.029	ND	ND	ND	0.180	0.117
Coffee (vending machine)	Ori	ND	0.062 ± 0.003	0.043 ± 0.002	0.296 ± 0.003	0.073 ± 0.003	0.176 ± 0.003	0.056 ± 0.004	0.055 ± 0.012	0.761	0.406
Coffee (instant mix)	Ori	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
Fruit and vegetable drink (n = 3 of 7)
Fruit confits	Ori	0.046 ± 0.004	0.042 ± 0.002	ND	ND	ND	ND	ND	ND	0.088	0.005
	Adding boiling water	ND	0.041 ± 0.005	ND	ND	ND	ND	ND	ND	0.041	0.000
Vegetable drink	Ori	0.049 ± 0.005	0.099 ± 0.012	ND	ND	0.217 ± 0.038	ND	ND	ND	0.365	0.223
Grain drink (n = 2 of 5)
Adlay powder	Ori	0.168 ± 0.001	0.284 ± 0.006	0.238 ± 0.004	0.176 ± 0.004	0.155 ± 0.008	0.150 ± 0.007	0.119 ± 0.016	0.248 ± 0.009	1.538	0.829
	Adding boiling water	0.062 ± 0.002	0.099 ± 0.009	ND	ND	0.092 ± 0.017	ND	ND	ND	0.253	0.099
Tea (n = 1 of 13)
Green tea bags	Ori	0.396 ± 0.007	1.712 ± 0.081	0.509 ± 0.015	0.569 ± 0.006	1.387 ± 0.032	0.737 ± 0.038	1.939 ± 0.029	0.544 ± 0.008	7.793	11.326
	Adding boiling water	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
Dairy product (n = 22 of 46)
Butter	Ori	0.043 ± 0.001	0.093 ± 0.001	ND	ND	ND	ND	ND	ND	0.136	0.005
	Stir-frying	0.082 ± 0.013	0.135 ± 0.014	0.151 ± 0.029	0.489 ± 0.006	0.210 ± 0.005	ND	0.189 ± 0.010	0.524 ± 0.053	1.780	1.234
	Grilling	0.096 ± 0.008	0.149 ± 0.010	0.107 ± 0.011	0.625 ± 0.022	0.184 ± 0.019	ND	0.174 ± 0.008	0.433 ± 0.013	1.768	1.143
	Boiling after stir-frying	0.058 ± 0.000	0.228 ± 0.007	ND	ND	ND	ND	ND	ND	0.286	0.008
Peanut butter	Ori	0.144 ± 0.003	0.184 ± 0.004	0.356 ± 0.004	0.092 ± 0.003	0.302 ± .003	0.259 ± 0.010	0.186 ± 0.003	0.345 ± 0.006	1.868	1.322
Milk (high fat)	Ori	ND	0.045 ± 0.014	ND	ND	ND	ND	ND	ND	0.045	0.000
Mozzarella cheese	Grilling	0.056 ± 0.002	0.148 ± 0.031	ND	0.112 ± 0.009	ND	ND	ND	ND	0.316	0.018
	Air-frying	ND	0.083 ± 0.006	ND	0.099 ± 0.003	ND	ND	ND	ND	0.182	0.011
Processed cheese	Ori	0.087 ± 0.010	0.176 ± 0.002	ND	ND	ND	ND	ND	ND	0.263	0.010
	Boiling	ND	0.043 ± 0.001	ND	ND	ND	ND	ND	ND	0.043	0.000
Cream	Ori	0.043 ± 0.002	0.144 ± 0.001	0.158 ± 0.016	ND	ND	ND	ND	0.131 ± 0.026	0.476	0.023
Cream cheese	Ori	0.056 ± 0.004	0.091 ± 0.002	0.125 ± 0.012	ND	0.061 ± 0.003	ND	ND	ND	0.333	0.080
Coffee creamer	Ori	0.093 ± 0.004	ND	0.547 ± 0.008	0.434 ± 0.027	0.338 ± 0.012	1.280 ± 0.040	0.269 ± 0.002	0.300 ± 0.006	3.261	1.921
	Adding boiling water	ND	0.047 ± 0.002	ND	ND	0.195 ± 0.049	ND	ND	ND	0.242	0.195
Parmesan cheese	Ori	ND	0.063 ± 0.003	ND	ND	ND	ND	ND	ND	0.063	0.001
Skim milk powder	Ori	ND	0.081 ± 0.003	ND	ND	ND	ND	ND	ND	0.081	0.001
	Adding boiling water	ND	0.051 ± 0.004	ND	ND	ND	ND	ND	ND	0.051	0.001
Whole milk powder	Ori	ND	0.121 ± 0.005	ND	ND	ND	ND	0.285 ± 0.003	ND	0.406	1.426
	Adding boiling water	ND	0.076 ± 0.004	ND	ND	ND	ND	0.145 ± 0.015	ND	0.221	0.726
Infant formula (1)e	Ori	0.106 ± 0.002	0.245 ± 0.022	0.146 ± 0.001	0.086 ± 0.000	0.066 ± 0.004	ND	0.151 ± 0.010	ND	0.799	0.857
Infant formula (2)	Ori	0.137 ± 0.002	0.266 ± 0.002	0.168 ± 0.005	0.096 ± 0.003	0.065 ± 0.004	ND	ND	ND	0.732	0.108
Infant formula (3)	Ori	0.095 ± 0.002	0.234 ± 0.009	0.143 ± 0.004	0.092 ± 0.012	0.068 ± 0.003	ND	ND	0.112 ± 0.004	0.744	0.104

Values represent the mean ± standard deviation of experiments performed in triplicate

^aΣPAH8: Sum of eight PAHs

^bΣTEQ_Bap: Sum of analyte concentrations of BaP toxic equivalent factor

^cND: Not detected (value was less than the limit of detection)

^dOri: Samples without cooking process

^eInfant formula 1: baby milk for infants under 100 days old; Infant formula 2: for infants between 100 days and 6 months old; Infant formula 3: for infants between 6 and 12 months old

Fig. 1.

Average of sum of analyte concentrations of benzo[a]pyrene (BaP) toxic equivalent factor (ΣTEQbap) in each beverage and dairy product. Error bar indicates standard deviation

Alcoholic samples had PAH8 levels of 0.041–0.399 μg/kg and coffee samples ranged from 0.18 to 0.761 μg/kg, with 0.043–3.261 μg/kg in dairy products and 0.041–0.365 μg/kg in fruit and vegetable drinks. PAH8 was detected in green tea bags with Ori with 7.793 µg/kg. BaP was also the highest value in this experiment with 1.387 ± 0.032 µg/kg, followed by adlay powder PAH8 at 1.538 µg/kg. A previous study investigating PAHs in tea and green tea purchased from the South Korean market reported ranges of BaP of ND–9.98 µg/kg, PAH4 (BaA, Chry, BbF, and BaP) of 2.25–23 µg/kg, and adlay powder PAH4 of ND–2.47 µg/kg (Lee et al., 2018a). These results were similar to the results of the current study. According to the cooking recipe, the value of PAHs was decreased when boiling or adding boiling water was applied except plum wine. The PAH8 of green tea was lowered from 7.793 g/kg to ND by using a boiling water formula to extract flavor and taste by soaking it in water. Although PAHs have a poor water solubility, resulting in a low infusion of PAHs from tea to water, other studies have shown that repeated hot water extraction accounts for about 1%–50% of the infusion (Oranuba et al., 2019). In the case of vending machine coffee, which was an instant coffee mix product, 0.761 µg/kg PAH8 was detected. PAHs were ND in products purchased from the market. This was likely due to the inflow of PAHs due to the contamination of water or raw material stored in the vending machine.

PAHs were also detected in products from fruits, cereals, and vegetables. In vegetable drinks, PAH8 was detected at 0.365 µg/kg and from 0.041 to 0.399 µg/kg in alcoholic drinks such as wine, beer, and vodka. PAH8 was also detected in beers (0.48 µg/kg) and wine (0.85 µg/kg) purchased in markets in Spain, respectively (Rascón et al., 2019). For products based on fruits, vegetables, and grains, PAHs can accumulate in the environment because of the wax layer in the peel of the raw material or can become contaminated by lubricants in the harvesting machine (Machado et al., 2014). Alcoholic beverages are kept in a wooden bottle for a prolonged period of time during fermentation. Wood tanks or wood chips that are made from repeated fire-drying and roasting processes can be sources of PAHs (Chinnici et al., 2007).

In the dairy products, PAHs were detected in butter, high-fat milk, cheese, creamer, milk powder, and infant formula. The content in butter was 0.136 µg/kg in the uncooked original state (Ori) and 0.286–1.78 µg/kg in the cooked product (Table 2). The value of PAHs was increased when heat treatment such as stir-frying and grilling was applied. The highest PAH increase was observed in butter with a high fat content during the heat treatments of stir-frying (1.78 µg/kg) and grilling (1.768 µg/kg). Boiling after stir-frying resulted in an increase in PAH content (0.286 µg/kg). The PAH8 content of nonfat dry milk powder (0.081 µg/kg) was lower than that of whole milk powder (0.406 µg/kg). In the infant formula 1 to 3, the PAH8 content ranged from 0.732 to 0.799 μg/kg. Infant formula 1 is baby milk for infants aged up to 100 days, infant formula 2 is for infants aged 100 days to 6 months, and infant formula 3 is for infants aged 6–12 months old. A study from Nigeria analyzed the PAH8 content in infant formula. Values were 0.071–1.719 µg/kg for products for infants up to 6 months old, 0–1.385 µg/kg for products for infants 6–12 months old, and 0–0.402 µg/kg for products for infants 0–12 months old (Iwegbue et al., 2014). Milk powder and baby formula were heat-treated with a spray dryer during the drying process, which can produce PAHs (Zink, 2003). EC Regulation No. 836/2011 defines 1 µg/kg for PAH4 as the maximum reference level for infant formula (European Commission, 2011). Presently, baby formula above the reference value was not observed.

Risk assessment of PAHs with age

TEQ values of PAH8 and food intake according to age group in South Korea were used to obtain the MOE. For all ages in each of six categories, the average of the margin of exposure (MOE) based on PAH8 in the mean and 97.5 percentile (P97.5) intake group was seen (Fig. 2). The intake information used in the mean intake value (Table 3) and 97.5 percentile (P97.5) intake values (Table 4) reflected the EFSA’s PAH risk assessment opinion in food (EFSA, 2008). Age groups were categorized as all ages, 1–2, 3–6, 7–12, 13–19, 20–64, and > 64 years based on KNHANES. Insufficient intake data on intake was indicated as not available (NA). In the mean intake group for all ages, MOE values ranged from 1.74 × 10⁵ to 4.65 × 10¹⁰ (negligible concern). In the P97.5 intake group, MOE values ranged from 9.14 × 10⁴ to 5.74 × 10⁹ (low to negligible concern). MOE values < 10⁴ indicating possible concern were not found, even in the P97.5 intake group. However, values indicative of low concern were found in infant formula 1 (1–2 years in both intake groups), whole milk powder (1–2 years in P97.5 intake group), rice wine (all ages and > 20 years in P97.5 intake), Korean canned beer (13–19 years in P97.5 intake), and vegetable drink (7–12 years in P97.5 intake) with a range of 3.60 × 10⁴ to 9.93 × 10⁴.

Fig. 2.

Average of margin of exposure (MOE) based on PAH8 in the mean and 97.5 percentile (P97.5) intake group for all ages in each of six categories. Error bar indicates standard deviation

Table 3.

Margin of exposure (MOE) of the mean intake groups of PAH8 in beverages and dairy products for each age group

MOE of the mean intake groups
Sample name	Recipe	All ages	1–2 years	3–6 years	7–12 years	13–19 years	20–64 years	≥ 64 years
Alcohol drink
Clear rice wine	Grilling	1.14 × 1010	3.52 × 1010	2.99 × 1010	2.85 × 1010	2.78 × 1010	9.09 × 109	1.99 × 1010
Korean bottled beer	Ori	4.71 × 105	NAa	NA	NA	1.22 × 106	5.08 × 105	5.49 × 105
Korean canned beer	Ori	6.67 × 105	NA	NA	NA	3.92 × 105	7.49 × 105	7.31 × 105
Plum wine	Boiling	2.74 × 106	NA	NA	NA	2.86 × 106	2.87 × 106	3.21 × 106
Raspberry wine	Ori	4.01 × 108	NA	NA	NA	NA	4.11 × 108	6.32 × 108
Red wine	Ori	3.67 × 106	7.01 × 108	4.12 × 108	8.15 × 108	6.16 × 106	2.80 × 106	7.64 × 106
	Stir-frying	6.90 × 107	1.32 × 1010	7.74 × 109	1.53 × 1010	1.16 × 108	5.27 × 107	1.44 × 108
Rice wine	Ori	3.17 × 105	NA	NA	NA	8.31 × 105	3.37 × 105	4.03 × 105
Vodka	Ori	1.68 × 107	NA	NA	NA	1.29 × 107	2.31 × 107	2.42 × 107
White wine	Ori	1.91 × 107	2.78 × 108	1.35 × 108	1.82 × 108	3.12 × 108	1.71 × 107	8.99 × 107
Coffee
Coffee (bean)	Ori	4.35 × 107	NA	2.71 × 109	1.53 × 108	3.20 × 107	4.58 × 107	5.91 × 107
	Adding boiling water	1.37 × 107	NA	8.52 × 108	4.81 × 107	1.01 × 107	1.44 × 107	1.86 × 107
Coffee (vending machine)	Ori	7.12 × 105	NA	NA	NA	NA	7.15 × 105	1.13 × 107
Fruit and vegetable drink
Fruits confits	Ori	1.64 × 108	1.93 × 108	1.04 × 108	1.50 × 108	1.34 × 108	1.71 × 108	1.79 × 108
	Adding boiling water	5.62 × 108	6.58 × 108	3.54 × 108	5.13 × 108	4.59 × 108	5.83 × 108	6.12 × 108
Vegetable drink	Ori	6.03 × 105	2.56 × 105	3.74 × 105	3.37 × 105	5.66 × 105	6.49 × 105	6.23 × 105
Grain drink
Adlay powder	Ori	1.60 × 106	NA	7.23 × 105	9.85 × 105	1.36 × 106	1.65 × 106	1.97 × 106
	Adding boiling water	2.34 × 106	NA	1.06 × 106	1.44 × 106	1.99 × 106	2.41 × 106	2.88 × 106
Tea
Green tea bags	Ori	1.22 × 106	NA	NA	NA	NA	1.34 × 106	NA
Dairy product
Butter	Ori	1.75 × 109	1.03 × 109	8.97 × 108	1.10 × 109	1.58 × 109	1.88 × 109	1.92 × 109
	Stir-frying	7.66 × 106	4.50 × 106	3.93 × 106	4.80 × 106	6.93 × 106	8.26 × 106	8.39 × 106
	Grilling	1.02 × 107	5.97 × 106	5.22 × 106	6.37 × 106	9.21 × 106	1.10 × 107	1.11 × 107
	Boiling after stir-frying	6.14 × 108	3.60 × 108	3.15 × 108	3.85 × 108	5.56 × 108	6.62 × 108	6.73 × 108
Peanut butter	Ori	1.33 × 106	8.69 × 105	8.47 × 105	1.39 × 106	2.98 × 106	1.27 × 106	1.41 × 106
Mozzarella cheese	Grilling	1.44 × 108	2.12 × 108	9.68 × 107	1.12 × 108	1.04 × 108	1.53 × 108	2.30 × 108
	Air-frying	2.23 × 108	3.28 × 108	1.50 × 108	1.73 × 108	1.61 × 108	2.36 × 108	3.56 × 108
Processed cheese	Ori	1.54 × 108	2.80 × 107	2.30 × 107	6.01 × 107	2.79 × 108	2.14 × 108	1.43 × 108
	Boiling	2.96 × 108	5.37 × 107	4.41 × 107	1.15 × 108	5.36 × 108	4.11 × 108	2.74 × 108
Cream	Ori	2.88 × 107	3.13 × 107	1.38 × 108	1.96 × 107	1.55 × 107	3.29 × 107	7.29 × 108
Cream cheese	Ori	2.73 × 107	5.98 × 107	1.92 × 107	1.41 × 107	2.73 × 107	2.80 × 107	3.26 × 107
Coffee creamer	Ori	1.39 × 106	NA	4.72 × 107	1.10 × 107	2.10 × 106	1.43 × 106	1.87 × 106
	Adding boiling water	1.06 × 106	NA	3.59 × 107	8.40 × 106	1.60 × 106	1.09 × 106	1.42 × 106
Parmesan cheese	Ori	4.65 × 1010	4.24 × 1010	2.59 × 1010	5.15 × 1010	1.69 × 1010	5.67 × 1010	7.84 × 1011
Skim milk powder	Ori	1.14 × 109	1.05 × 109	9.11 × 108	7.99 × 108	9.86 × 108	1.18 × 109	2.30 × 109
	Adding boiling water	1.01 × 109	9.31 × 108	8.11 × 108	7.11 × 108	8.78 × 108	1.05 × 109	2.05 × 109
Whole milk powder	Ori	7.95 × 105	1.20 × 105	2.60 × 105	1.73 × 106	5.16 × 105	8.68 × 105	1.55 × 106
	Adding boiling water	8.52 × 105	1.29 × 105	2.79 × 105	1.85 × 106	5.53 × 105	9.30 × 105	1.66 × 106
Infant formula (1)b	Ori	1.74 × 105	3.60 × 104	NA	NA	NA	NA	NA
Infant formula (2)	Ori	6.20 × 106	1.13 × 106	8.55 × 107	NA	NA	NA	NA
Infant formula (3)	Ori	3.83 × 106	7.49 × 105	1.58 × 106	NA	NA	2.18 × 107	NA

MOE < 10⁴: possible concern; 10⁴ < MOE < 10⁵: low concern; 10⁵ < MOE: negligible concern

^aNA: Not available, the intake is almost zero

^bInfant formula 1: baby milk for infants under 100 days old; Infant formula 2: for infants between 100 days and 6 months old; Infant formula 3: for infants between 6 and 12 months old

Table 4.

MOE of PAH8 in beverage and dairy products for each age group in the 97.5 percentile (P97.5) intake groups

MOE of P97.5 intake groups
Sample name	Recipe	All ages	1–2 years	3–6 years	7–12 years	13–19 years	20–64 years	≥ 64 years
Alcohol drink
Clear rice wine	Grilling	1.98 × 109	6.64 × 109	8.15 × 109	1.12 × 1010	4.31 × 109	8.87 × 108	2.53 × 109
Korean bottled beer	Ori	1.25 × 105	NA	NA	NA	5.89 × 105	1.37 × 105	2.07 × 105
Korean canned beer	Ori	1.95 × 105	NA	NA	NA	9.93 × 104	2.23 × 105	1.94 × 105
Plum wine	Boiling	8.26 × 105	NA	NA	NA	2.52 × 106	9.09 × 105	1.23 × 106
Raspberry wine	Ori	8.18 × 107	NA	NA	NA	NA	9.00 × 107	1.09 × 108
Red wine	Ori	7.93 × 105	5.03 × 108	7.87 × 107	3.86 × 108	1.01 × 106	8.73 × 105	3.16 × 106
	Stir-frying	1.49 × 107	9.45 × 109	1.48 × 109	7.25 × 109	1.90 × 107	1.64 × 107	5.94 × 107
Rice wine	Ori	9.14 × 104	NA	NA	NA	2.61 × 105	9.41 × 104	9.54 × 104
Vodka	Ori	8.83 × 106	NA	NA	NA	8.99 × 106	1.34 × 107	2.42 × 107
White wine	Ori	1.27 × 106	1.14 × 108	4.10 × 107	7.15 × 107	1.02 × 108	1.10 × 106	8.70 × 106
Coffee
Coffee (bean)	Ori	1.16 × 107	NA	1.58 × 109	1.64 × 107	8.85 × 106	1.28 × 107	1.74 × 107
	Adding boiling water	3.66 × 106	NA	4.98 × 108	5.16 × 106	2.78 × 106	4.01 × 106	5.47 × 106
Coffee (vending machine)	Ori	3.53 × 106	NA	NA	NA	NA	3.88 × 105	1.13 × 107
Fruit and vegetable drink
Fruits confits	Ori	4.88 × 107	6.73 × 107	3.89 × 107	6.20 × 107	7.58 × 107	4.91 × 107	2.26 × 107
	Adding boiling water	1.67 × 108	2.30 × 108	1.33 × 108	2.12 × 108	2.59 × 108	1.68 × 108	7.71 × 107
Vegetable drink	Ori	2.10 × 105	1.74 × 105	1.99 × 105	9.90 × 104	1.92 × 105	2.31 × 105	1.57 × 105
Grain drink
Adlay powder	Ori	4.96 × 105	NA	3.53 × 105	3.69 × 105	4.66 × 105	5.46 × 105	6.95 × 105
	Adding boiling water	7.25 × 105	NA	5.16 × 105	5.39 × 105	6.80 × 105	7.97 × 105	1.02 × 106
Tea
Green tea bags	Ori	3.70 × 105	NA	NA	NA	NA	4.07 × 105	NA
Dairy product
Butter	Ori	3.25 × 108	2.34 × 108	1.97 × 108	2.52 × 108	3.84 × 108	3.47 × 108	3.76 × 108
	Stir-frying	1.42 × 106	1.03 × 106	8.64 × 105	1.11 × 106	1.68 × 106	1.52 × 106	1.65 × 106
	Grilling	1.89 × 106	1.36 × 106	1.15 × 106	1.47 × 106	2.24 × 106	2.02 × 106	2.19 × 106
	Boiling after stir-frying	1.14 × 108	8.24 × 107	6.93 × 107	8.87 × 107	1.35 × 108	1.22 × 108	1.32 × 108
Peanut butter	Ori	4.71 × 105	8.69 × 105	4.50 × 105	4.79 × 105	2.16 × 106	3.11 × 105	7.02 × 105
Mozzarella cheese	Grilling	3.89 × 107	7.61 × 107	2.07 × 107	2.47 × 107	2.99 × 107	4.37 × 107	6.54 × 107
	Air-frying	6.01 × 107	1.18 × 108	3.19 × 107	3.82 × 107	4.62 × 107	6.75 × 107	1.01 × 108
Processed cheese	Ori	5.12 × 107	1.42 × 107	9.04 × 106	2.70 × 107	7.82 × 107	6.23 × 107	4.59 × 107
	Boiling	9.82 × 107	2.73 × 107	1.73 × 107	5.18 × 107	1.50 × 108	1.20 × 108	8.81 × 107
Cream	Ori	6.52 × 106	6.47 × 106	6.13 × 106	4.14 × 106	5.31 × 106	1.26 × 107	2.57 × 108
Cream cheese	Ori	6.02 × 106	2.87 × 107	4.61 × 106	6.37 × 106	1.23 × 107	6.63 × 106	1.20 × 107
Coffee creamer	Ori	4.03 × 105	NA	4.72 × 107	6.63 × 105	4.40 × 105	4.43 × 105	7.03 × 105
	Adding boiling water	3.07 × 105	NA	3.59 × 107	5.05 × 105	3.35 × 105	3.38 × 105	5.35 × 105
Parmesan cheese	Ori	5.74 × 109	1.14 × 1010	1.13 × 1010	1.08 × 1010	3.51 × 109	6.31 × 109	5.33 × 1011
Skim milk powder	Ori	4.05 × 108	5.72 × 108	4.41 × 108	7.53 × 108	4.23 × 108	4.45 × 108	2.07 × 109
	Adding boiling water	3.60 × 108	5.09 × 108	3.93 × 108	6.70 × 108	3.76 × 108	3.96 × 108	1.84 × 109
Whole milk powder	Ori	2.62 × 105	5.42 × 104	1.03 × 105	3.48 × 105	5.16 × 105	2.97 × 105	1.20 × 106
	Adding boiling water	2.81 × 105	5.80 × 104	1.10 × 105	3.73 × 105	5.53 × 105	3.19 × 105	1.29 × 106
Infant formula (1)a	Ori	1.74 × 105	3.60 × 104	NA	NA	NA	NA	NA
Infant formula (2)	Ori	2.72 × 106	5.62 × 105	8.55 × 107	NA	NA	NA	NA
Infant formula (3)	Ori	1.34 × 106	1.11 × 105	1.58 × 106	NA	NA	2.18 × 107	NA

MOE < 10⁴: possible concern; 10⁴ < MOE < 10⁵: low concern; 10⁵ < MOE: negligible concern

^aInfant formula 1: baby milk for infants under 100 days old; Infant formula 2: for infants between 100 days and 6 months old; Infant formula 3: for infants between 6 and 12 months old

In conclusion, samples purchased from 21 markets in 10 cities in South Korea were used for TDS “as consumed” in two categories of beverage and dairy products for the measurement of PAH8. PAHs were detected in 41 of the total of 115 samples, with the highest PAH8 content in green tea bags. Samples treated via stir-frying and grilling recipes displayed higher PAH8 values than the original samples. The analysis indicates that the values of MOE are generally safe in beverage and dairy table-ready forms. Infant formula, whole milk powder, rice wine, Korean canned beer, and vegetable drink commodities can be consumed with low concern.

Supplementary Information

Below is the link to the electronic supplementary material.

Funding

This research was supported by a Grant (18162MFDS053-4) from the Ministry of Food and Drug Safety in 2019 and the School of Life Sciences & Biotechnology of Korea University for BK21PLUS.

Declarations

Conflict of interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.