Elsevier

Food Chemistry

Volume 156, 1 August 2014, Pages 296-300
Food Chemistry

Analytical Methods
Determination of polycyclic aromatic hydrocarbons [PAHs] in processed meat products using gas chromatography – Flame ionization detector

https://doi.org/10.1016/j.foodchem.2014.01.120Get rights and content

Highlights

  • Selected PAHs fractions were determined in some processed meats using gas chromatograph – flame ionization detector.

  • Beef stripes, pork and chicken fillets were bought and processed by smoking, grilling and boiling.

  • PAHs in processed meat samples were hydrolyzed in methanolic KOH and extracted in n-hexane.

  • The recovery, repeatability and reproducibility and precision are comparable with other methods.

  • The levels PAHs fractions in processed meat is a function of meat type and the methods of preparation.

Abstract

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in smoked, grilled and boiled meats were determined using gas chromatographyflame ionization detector (GC–FID). PAHs in the processed meats were extracted in n-hexane after hydrolysis with methanolic KOH. Clean-up was achieved using solid phase extraction in neutral-Si/basic-Si/acidic-Si/neutral-Si frits. The fractions, benzo[k]fluoranthene (BkP), benzo[a]pyrene (BaP), indeno[123-cd]pyrene (IP) and benzo[ghi]perylene (BghiP) were separated and quantified using GC–FID. The method and instrument limits of detections were 0.1, 0.1, 0.2, 0.3 μg/kg and 0.5, 0.5, 1.0, 1.5 μg/kg, respectively, for BkP, BaP, IP and BghiP. The method’s recovery and precision generally varied between 83.69% and 94.25% with relative standard deviation (RSD) of 3.18–15.60%; and 90.38–96.71% with relative standard deviation (RSD) of 1.82–12.87% respectively. The concentration of BkP, BaP, IP and BghiP in smoked, grilled and boiled meat samples were ranged 0.64–31.54 μg/kg, 0.07–7.04 μg/kg, 0.09–15.03, 0.51–46.67 μg/kg and 0.01–5.11 μg/kg, respectively.

Introduction

Polycyclic aromatic hydrocarbons (PAHs) occur naturally as components of carbonaceous materials and fossil fuels. They are anthropogenically released into the environment from human activities, especially those involving thermal processes such as the partial or complete combustion of carbon containing materials. The smoke produced during thermal and combustion processes were reported to contains more than 300 detectable chemical compounds including PAHs, phenols, carbonyls, acids, alcohols and esters, furans, and lactones (Reiner, 1977). The aerodynamic character of smoke results in the wide distribution of PAHs in the environment. They are thus found in air, water, soil and foods.

Polycyclic aromatic hydrocarbons are classified as light or heavy fractions based on the number of fused aromatic rings contained in their structure. The light PAHs contains less than 4 member fused aromatic rings, while the heavy PAHS contains more than 4 member fused aromatic rings aromatic. The light PAH (L-PAH) fractions are volatile, and volatility decreases with an increase in the number of aromatic rings in their structure. Heavy PAH (H-PAH) fractions however, are more stable and are found in many environmental matrices. Polycyclic aromatic hydrocarbons are generally lipophilic, with members of each class having similar character and subject to the same environmental fate.

Substantial amount of PAHs have been reported in both thermally processed and some unprocessed foods (Phillips, 1999; Gomaa et al., 1993, Organizacion Panoamericana de la Salud, 1985). This is because heat treatments such as smoking, roasting, grilling, and boiling used in processing food for edibility result in the addition and or formation of PAHs in foods, especially meat. The nature and type of PAHs produced during thermal processes such as combustion, is a function of a number of factors such as wood/coal type, combustion nature (complete or incomplete), the nature of heat source, and prevailing temperature of heat source (Fretheim, 1983, Lijinsky and Shubik, 1964). Dietary exposure of humans to PAHs in processed food is therefore inevitable.

Over 200 PAH fractions are known. Many of these fractions or compounds may occur at mg/kg or μg/kg concentration levels. Reiner (1977) emphasized the need for analytical procedures which allow for the detection of as many fractions or members of PAH compound present in heat processed food. Such methods will allow for suitable toxicology evaluations, as well as the evaluation of the effect of heat processing on foods and meat, and its dependence on heat processing methods.

The earliest method used for separation and analysis of the various fractions of PAH was thin layer chromatography (TLC). The use of ultra-violet absorption and fluorescence detection (UV–FLD), after separation by high performance liquid chromatography (HPLC), and gas chromatography with mass selective or flame ionization detector (GC–MS or GC–FID) is widely used (Al-Rashdan et al., 2010, Fazio et al., 1973). Contemporary methods involve pre-separation and separation by high performance liquid chromatography coupled on-line to GC with flame ionization detection (HPLC–GC–FID) and GC–GC–FID, although this is of limited use for routine analysis. The European Food Safety Agency (EFSA, 2012) noted that the detection limit for this procedure was a function of the mass distribution, the sample matrix and any prior enrichment, and this can be as low as 0.1 mg/kg. Suitable, fast and reliable method for food especially meat and meat product is however challenging. This is because of the association of meat with cholesterol, lipids and fats due to their lipophilic nature and character. There is a need for rapid, efficient and accurate routine monitoring of PAHs in thermally processed foods, especially meat and meat products.

In this study, Gas Chromatography with Flame Ionization Detection (GC–FID) was used to separate and quantify the concentrations of benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[123-cd]pyrene (IP) and benzo[ghi]perylene (BghiP) in polycyclic aromatic hydrocarbon [PAH] extracts from smoked, grilled and boiled meat.

Section snippets

Standards and calibration solution

Polycyclic aromatic hydrocarbon standards namely benzo[k]fluoranthene, benzo[a]pyrene, indeno[123-cd]pyrene and benzo[ghi]perylene (neats), were obtained from Supelco, Bellefonte, PA, USA. Stock solutions of each of the PAHs were prepared by dissolving 0.01 g in 1:4 mixtures of high purity dichloromethane and n-hexane (Sigma–Aldrich, Germany). The stock solutions were stored in amber flasks at −4 °C. Working calibration solutions were subsequently prepared by serial dilution from the stock

Performance of the GC–FID procedure

The chromatogram of the standard cocktail mix of the selected PAH fractions, is presented in Fig. 1. The chromatograms showed the separation of the selected PAHs standards in terms of retention time. The chromatogram of the PAHs extracts from the meat samples were also analysed along with blank, in order to correct for the target PAHs fractions. The recoveries of PAHs were evaluated by the use of an internal PAH standards of containing BaP and IP, since all PAHs behave in a similar fashion

Conclusion

Polycyclic aromatic hydrocarbons (PAHs); benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[123-cd]pyrene (IP) and benzo[ghi]perylene (BghiP) were detected and quantified using Gas Chromatography with Flame Ionization Detector (GC–FID). The concentrations of the PAH fractions in the differently processed meat types and the total PAHs concentrations were variable. The variability in the concentration levels is dependent on the PAHs sources and their isomeric derivative type, based on such

References (14)

  • K. Fretheim

    Polycyclic aromatic hydrocarbons in grilled meat products – A review

    Food Chemistry

    (1983)
  • D.H. Phillips

    Polycyclic aromatic hydrocarbons in the diets

    Mutation Research

    (1999)
  • P. Simko et al.

    Influence of cooking on Benzo[a]pyrene content in smoked saugages

    Meat Science

    (1993)
  • A. Al-Rashdan et al.

    Determination of the levels of polycyclic aromatic hydrocarbons in toasted bread using gas chromatography mass spectrometry

    International Journal of Analytical Chemistry

    (2010)
  • N.Y. Chen et al.

    M2 Forming – A process for aromatization of light hydrocarbons

    Industrial and Engineering Chemistry Process Design and Development

    (1986)
  • EFSA

    The european food safety authority (EFSA), opinion on mineral oil hydrocarbons in foods

    EFSA Journal

    (2012)
  • T. Fazio et al.

    Collaborative study of the multicomponent method for polycyclic aromatic hydrocarbons in foods

    Journal of the Association of Official Analytical Chemists

    (1973)
There are more references available in the full text version of this article.

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