Doehlert experimental design; HPLC/GC × GC-FID; MOAH; Refining; activated carbon; adsorption; bleaching; food contaminants; mineral oil; mitigation; palm oil; response surface methodology; Aromatic rings; Doehlert; GC×GC; Mineral oil aromatic hydrocarbon; Oil hydrocarbons; Response-surface methodology; Food Science; Chemistry (all); Toxicology; Public Health, Environmental and Occupational Health; Health, Toxicology and Mutagenesis
Abstract :
[en] Mineral oil hydrocarbons (MOH) are lipophilic food contaminants that can be present in edible oils. Mineral oil aromatic hydrocarbons (MOAH) are a sub-fraction of MOH and are of particular concern for the European Food Safety Authority (EFSA), as MOAH containing three or more aromatic rings are considered potentially genotoxic. Several studies have shown that certain steps in vegetable oil refining can reduce MOH levels. Deodorisation, in particular, has been reported to significantly decrease overall MOH concentrations. More recently, bleaching with activated carbon (AC) has also been identified as a possible mitigation tool for MOAH. However, no quantitative study has been conducted yet on real edible oil matrices examining the effect of bleaching treatments on MOAH subclasses. The objective of this study was therefore to investigate the effect in spiked palm oil of AC bleaching on the mitigation of MOAH sub-classes (i.e. C-fraction and number of aromatic rings), using HPLC/GC × GC-FID. Two palm oils (preliminary differently treated) were tested with two types of AC. The mitigation effect was evaluated using a Doehlert experimental design combined with response surface methodology, assessing different temperatures (60-80-100 °C) and AC dosages (0.3-0.68-1.05-1.43-1.8%, w/w). Pressure (50 mbar absolute) and contact time (30 min) were kept constant. The results demonstrated that MOAH with three or more aromatic rings can be significantly mitigated by AC bleaching, whereas the adsorption of 1-2 rings MOAH occurred to a much lower extent. In addition to the aromatic ring number, the degree of alkylation influenced adsorption behaviour, with more highly alkylated MOAH showing lower affinity for AC. Among the investigated factors, AC concentration was the most influential parameter: increasing AC dosage led to greater MOAH reduction. Temperature also affected MOAH mitigation in an AC-type-dependent manner. Both AC types resulted in comparable maximal MOAH reductions in both oils, i.e. around 25-30%.
Disciplines :
Food science
Author, co-author :
Grandjean, Jérôme ; Université de Liège - ULiège > TERRA Research Centre > Technologie Alimentaire (TA)
Gorska, Aleksandra ; Université de Liège - ULiège > Département GxABT > Chemistry for Sustainable Food and Environmental Systems (CSFES)
Pallares Pallares, Andrea; Desmet Innovation Center, Zaventem, Belgium
Papastergiadis, Antonios; Desmet Innovation Center, Zaventem, Belgium
Danthine, Sabine ; Université de Liège - ULiège > TERRA Research Centre > Technologie Alimentaire (TA)
Purcaro, Giorgia ; Université de Liège - ULiège > Département GxABT > Chemistry for Sustainable Food and Environmental Systems (CSFES)
Language :
English
Title :
Activated carbon bleaching for MOAH mitigation in palm oil: a multi-parameter laboratory-scale study using HPLC/GC × GC-FID.
Publication date :
15 July 2026
Journal title :
Food Additives and Contaminants. Part A. Chemistry, Analysis, Control, Exposure and Risk Assessment
The authors would like to thank LECO and Restek for providing the analytical instruments and equipment used in this study. This work is supported by ACESSS (Academic Center of Excellence for Separation Science and Sensing). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society. The authors would also like to thank Kristof Meus and Jeroen Maes for their assistance with the practical execution of the trials at the Desmet Innovation Centre.
Aliyar-Zanjani N, Piravi-Vanak Z, Ghavami M., 2019. Study on the effect of activated carbon with bleaching earth on the reduction of polycyclic aromatic hydrocarbons (PAHs) in bleached soybean oil. Grasas Aceites. 70(2):e304. https://doi.org/10.3989/gya.0577181
Alvarez PM, García-Araya JF, Beltrán FJ, Masa FJ, Medina F., 2005. Ozonation of activated carbons: effect on the adsorption of selected phenolic compounds from aqueous solutions. J Colloid Interface Sci. 283(2):503–512. https://doi.org/10.1016/j.jcis.2004.09.014
Bauwens G, et al.2023. Investigation of the effect of refining on the presence of targeted mineral oil aromatic hydrocarbons in coconut oil. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 40(3):392–403. https://doi.org/10.1080/19440049.2022.2164621
Bauwens G, Barp L, Purcaro G., 2023. Validation of the liquid chromatography-comprehensive multidimensional gas chromatography-time-of-flight mass spectrometer/flame ionization detector platform for mineral oil analysis exploiting interlaboratory comparison data. Green Anal Chem. 4:100047. https://doi.org/10.1016/j.greeac.2022.100047
Bauwens G, Pantó S, Purcaro G., 2021. Mineral oil saturated and aromatic hydrocarbons quantification: mono- and two-dimensional approaches. J Chromatogr A. 1643:462044. https://doi.org/10.1016/j.chroma.2021.462044
Biedermann M, Fiselier K, Grob K., 2009. Aromatic hydrocarbons of mineral oil origin in foods: method for determining the total concentration and first results. J Agric Food Chem. 57(19):8711–8721. https://doi.org/10.1021/jf901375e
Biedermann M, Munoz C, Grob K., 2020. Epoxidation for the analysis of the mineral oil aromatic hydrocarbons in food. An update. J Chromatogr A. 1624:461236. https://doi.org/10.1016/j.chroma.2020.461236
Brühl L., 2016. Occurrence, determination, and assessment of mineral oils in oilseeds and vegetable oils. Euro J Lipid Sci Tech. 118(3):361–372. https://doi.org/10.1002/ejlt.201400528
Bu J, et al.2011. Desulfurization of diesel fuels by selective adsorption on activated carbons: competitive adsorption of polycyclic aromatic sulfur heterocycles and polycyclic aromatic hydrocarbons. Chem Eng J. 166(1):207–217. https://doi.org/10.1016/j.cej.2010.10.063
Carratalá-Abril J, Lillo-Ródenas M, Linares-Solano A, Cazorla-Amorós D., 2010. Regeneration of activated carbons saturated with benzene or toluene using an oxygen-containing atmosphere. Chem Eng Sci. 65(6):2190–2198. https://doi.org/10.1016/j.ces.2009.12.017
Carrillo J-C, et al.2022. Comparison of PAC and MOAH for understanding the carcinogenic and developmental toxicity potential of mineral oils. Regul Toxicol Pharmacol. 132:105193. https://doi.org/10.1016/j.yrtph.2022.105193
Carrillo J-C, Van Der Wiel A, Danneels D, Kral O, Boogaard PJ., 2019. The selective determination of potentially carcinogenic polycyclic aromatic compounds in lubricant base oils by the DMSO extraction method IP346 and its correlation to mouse skin painting carcinogenicity assays. Regul Toxicol Pharmacol. 106:316–333. https://doi.org/10.1016/j.yrtph.2019.05.012
Cerqueira UMFM, et al.2021. Doehlert design in the optimization of procedures aiming food analysis–a review. Food Chem. 364:130429. https://doi.org/10.1016/j.foodchem.2021.130429
Dowaidar AM, El‐Shahawi MS, Ashour I., 2007. Adsorption of polycyclic aromatic hydrocarbons onto activated carbon from non‐aqueous media: 1. the influence of the organic solvent polarity. Sep Sci Technol. 42(16):3609–3622. etnodéc https://doi.org/10.1080/01496390701626537
European Food Safety Authority Panel on Contaminants in the Food Chain [EFSA CONTAM].2012. Scientific opinion on mineral oil hydrocarbons in food. EFS2. 10(6). https://doi.org/10.2903/j.efsa.2012.2704
European Food Safety Authority Panel on Contaminants in the Food Chain [EFSA CONTAM].2023. Update of the risk assessment of mineral oil hydrocarbons in food. EFS2. 21(9). https://doi.org/10.2903/j.efsa.2023.8215
European Commission. 2022, 21 avril. Standing committee on plants, animals, food and feed section novel food and toxicological safety of the food chain [SCoPAFF].
European Commission. Joint Research Centre [JRC]. 2016. Guidance document on the estimation of LOD and LOQ for measurements in the field of contaminants in feed and food. LU: publications Office, Consulté le: 10 août 2025. Online. Disponible sur: https://data.europa.eu/doi/10.2787/8931.
European Commission. Joint Research Centre [JRC]. 2023. Guidance on sampling, analysis and data reporting for the monitoring of mineral oil hydrocarbons in food and food contact materials: in the frame of Commission Recommendation (EU) 2017/84. LU: Publications Office, Consulté le: 4 octobre 2024. Online. Available from: https://data.europa.eu/doi/10.2760/963728.
[EURL-PC] European Union Reference Laboratory for Processing Contaminants. et al. 2025. Analysis of MOSH and MOAH in food by GC × GC: guidance on analysis, interpretation and data reporting. Technical University of Denmark. https://doi.org/10.11581/FBE4E1CE-65C2-468F-9CEA-CB3A140BEADE
Franz M, Arafat HA, Pinto NG., 2000. Effect of chemical surface heterogeneity on the adsorption mechanism of dissolved aromatics on activated carbon. Carbon N Y. 38(13):1807–1819. https://doi.org/10.1016/S0008-6223(00)00012-9
Gharby S., 2022. Refining vegetable oils: chemical and physical refining. Sci World J. 2022:1–10. https://doi.org/10.1155/2022/6627013
Gibon V, De Greyt W, Papastergiadis A, Kellens M., 2022. Mineral oil hydrocarbons - a new challenge for the oils and fats processing industry. Accessed March 23, 2025. Available from: https://issuu.com/altitudedesign/docs/1701-a4-mineral_oil_hydrocarbons.
Gong Z, Alef K, Wilke B-M, Li P., 2007. Activated carbon adsorption of PAHs from vegetable oil used in soil remediation. J Hazard Mater. 143(1–2):372–378. https://doi.org/10.1016/j.jhazmat.2006.09.037
Gorska A, Bauwens G, Beccaria M, Purcaro G., 2025. Purification of mineral oil aromatic hydrocarbons and separation based on the number of aromatic rings using a liquid chromatography silica column. An alternative to epoxidation. J Chromatogr A. 1743:465684. https://doi.org/10.1016/j.chroma.2025.465684
Gorska A, Danthine S, Jacquet N, Purcaro G., 2024. Impact of deodorisation time and temperature on the removal of different MOAH structures: a lab-scale study on spiked coconut oil. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 41(9):1118–1131. https://doi.org/10.1080/19440049.2024.2371925
Gupta MK., 2017. Bleaching. In Practical guide to vegetable oil processing. Elsevier. p. 129–169. https://doi.org/10.1016/B978-1-63067-050-4.00006-4
Hochegger A, et al.2021. Mineral oil risk assessment: knowledge gaps and roadmap. Outcome of a multi-stakeholders workshop. Trends Food Sci Technol. 113:151–166. https://doi.org/10.1016/j.tifs.2021.03.021
[ISO] International Organization for Standardization. 2024. ISO 20122:2024—Vegetable oils—Determination of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) with online-coupled high performance liquid chromatography-gas chromatography-flame ionization detection (HPLC-GC-FID) analysis—Method for low limit of quantification. Online. Available from: https://www.iso.org/standard/86091.html.
Japir AA-W, et al.2017. Physicochemical characteristics of high free fatty acid crude palm oil. OCL. 24(5):D506. https://doi.org/10.1051/ocl/2017033
Jian MQ, Xie HH, Xia KL, Zhang YY., 2017. Challenge and opportunities of carbon nanotubes. In: Industrial applications of carbon nanotubes. Elsevier. p. 433–476. https://doi.org/10.1016/B978-0-323-41481-4.00015-0
Kiralan SS, Toptancı İ, Tekin A., 2019. Further evidence on the removal of polycyclic aromatic hydrocarbons (PAHs) during refining of olive pomace oil. Euro J Lipid Sci Tech. 121(4):1800381. https://doi.org/10.1002/ejlt.201800381
Moret S, Piazza A, Bouguerra MDE, Barp L., 2025. A preliminary study on the decontamination properties of different sorbent materials used for oil bleaching against mineral oils and selected alkylated polycyclic aromatic hydrocarbons. OCL. 32:13. https://doi.org/10.1051/ocl/2025005
Purcaro G, Barp L, Moret S., 2016. Determination of hydrocarbon contamination in foods. A review. Anal Methods. 8(29):5755–5772. https://doi.org/10.1039/C6AY00655H
Rich A., 1967. Major factors that influence bleaching performance. J Am Oil Chem Soc. 44(7):298A–323A.
Stauff A, Schnapka J, Heckel F, Matissek R., 2020. Mineral oil hydrocarbons (MOSH/MOAH) in edible oils and possible minimization by deodorization through the example of cocoa butter. Euro J Lipid Sci Tech. 122(7):1900383. https://doi.org/10.1002/ejlt.201900383
Torrents A, Damera R, Hao OJ., 1997. Low-temperature thermal desorption of aromatic compounds from activated carbon. J Hazard Mater. 54(3):141–153. https://doi.org/10.1016/S0304-3894(96)01878-X
Ursol LM, Conchione C, Peroni D, Moret S., 2025. A study on the impact of industrial-scale refining on olive oil and olive pomace oil contamination with mineral oils. Food Chem. 466:142207. https://doi.org/10.1016/j.foodchem.2024.142207
Usman MA, Ekwueme VI, Alaje TO, Mohammed AO., 2012. Characterization, acid activation, and bleaching performance of Ibeshe Clay, Lagos, Nigeria. ISRN Ceram. 2012:1–5. https://doi.org/10.5402/2012/658508
Veksha A, Uddin A, Sasaoka E, Kato Y., 2012. Adsorption and desorption behavior of benzene on activated carbons from different precursors in dry and humid conditions. J Chem Eng Japan / JCEJ. 45(6):387–394. https://doi.org/10.1252/jcej.11we255
Wagner C, et al.2001. Mineral paraffins in vegetable oils and refinery by-products for animal feeds.
Xiao X, et al.2015. Preparation of activated carbon from Xinjiang region coal by microwave activation and its application in naphthalene, phenanthrene, and pyrene adsorption. J Taiwan Inst Chem Eng. 53:160–167. https://doi.org/10.1016/j.jtice.2015.02.031
