Polycyclic Aromatic Hydrocarbons and Olive Pomace Oil

Abstract

The occurrence of polycyclic aromatic hydrocarbons (PAHs) in five samples of olive pomace oil has been studied to determine the contamination degree of this type of oil and to evaluate if specific purification steps must be introduced during its manufacture. The PAHs present have been determined by gas chromatography-mass spectrometry. A high number of PAHs, with a wide range of molecular weights and in very high concentrations, have been found in four of the samples studied. A very high number of alkyl derivatives and, in many cases, in higher concentrations than their respective parent PAHs, have also been identified. One of the samples, however, presents a more reduced number of PAHs and in significantly lower concentrations than the others. These findings reveal that it is necessary to introduce adequate cleanup steps in the manufacturing process of olive pomace oil, which can give rise to oils with a relatively low content of PAHs. Some carcinogenic PAHs have also been identified, both unalkylated and alkylated.

Method Validation and Determination of Polycyclic Aromatic Hydrocarbons in Vegetable Oils by HPLC-FLD

“…The highest PAHs contents (1.86 ± 0.28 μg/kg; 0.92 ± 0.14 μg/kg; 1.42 ± 0.21 μg/kg and 1.58 ± 0.24 μg/kg for BaP, BaA, CHR and BbFA, respectively) were found in one sample of refined sunflower oil originating from UE (Table 3); however, in this case the sum of four PAHs (5.78 ± 1.16 μg/kg) and BaP content did not exceed the permissible limits given in Commission Σ4PAHs sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene, and chrysene, LOD limit of detection, LOQ limit of quantification, n number of samples Regulation (EU) 2015/1125. The levels of contamination of the refined vegetable oils with PAHs are comparable to these found by other authors (Cejpek 1998;Guillen et al 2004;Teixeira et al 2007). Most authors (Ciecierska and Obiedziński 2006;Starski and Jędra 2011) reported that the PAHs content of edible oils was reduced as a result of refining process, especially by bleaching with use of a mixture of adsorbents (activated bleaching earth and activated charcoal) and by deodorisation, while Teixeira et al (2007) observed a slight increase in PAHs content of soybean oil and olive oil after the bleaching process.…”

“…Vegetable oils may be contaminated with PAHs as a result of processing, especially drying of oil plants and due to use of contaminated extraction solvent. To a lesser extent a contamination of these oils may be associated with environmental pollution (Guillen et al 2004;Lage Yusty and Cortizo Daviña, 2005;Moret et al 2005;WHO 2010;Bojanowska and Czerwiński 2010); however, in a case of high air pollution with PAHs and due to atmospheric precipitation, a superficial contamination of plants during growing season may occur. This contamination may be then transferred to the final product (Rodríguez-Acuna et al 2008).…”

“…On the other hand, direct impact of exhaust gases during drying of the seeds and/or impact of high temperature during extraction of oil from seeds result in increased amount of polyaromatic hydrocarbons in a final product. Many researchers observed significant differences in the level of PAHs in different production batches of the same type of oil (Cejpek et al 1998;Tys et al 2003;Guillen et al 2004).…”

Polycyclic Aromatic Hydrocarbons (PAH) in Olive Oils and Other Vegetable Oils; Potential for Carcinogenesis

“…A high number of PAH with a wide range of molecular weights can be found in vegetable oils, of which many are alkylated compounds, although they are ignored by legal regulations (Guillén et al, 2004).…”

“…In a wide variety of plants, three possible sources of contamination by PAH have been considered: uptake as a result of atmospheric exposure, uptake from the soil and endogenous biosynthesis (Phillips, 1999). However, atmospheric pollution is considered by most investigators as the main source of contamination of unprocessed foods (Guillén et al, 2004;Rodríguez-Acuña et al, 2008). Around 70 different PAH or related compounds have been identified in foodstuffs, from which benzo[a]pyrene and benz [a]anthracene are the most abundant, existing in high quantities in cooked or smoked meat products (Smith et al, 2001).…”