Mineral oil hydrocarbons in foods: is the data reliable?

Coffee and mineral oil hydrocarbons: potential dietary intake

Levels of mineral oil hydrocarbons were measured in a large range of green and roasted coffee beans or ground powder. To better understand the consumer exposure to mineral oil hydrocarbons, the transfer to the brewed coffee was assessed under three different preparations. As a result, less than 5% of mineral oil hydrocarbons were transferred to the cup. With this low transfer rate, the coffee contribution to the mineral oils daily intake can be assessed to be very low, below 0.8% of the total exposure.

Optimization of sample clean-up for the determination of small amounts of MOSH and MOAH in edible oils - method DGF C-VI 22 (20)

Methods for determining MOSH and MOAH in edible oils showed major problems with interlaboratory comparability of analytical results, especially in the lower concentration range below 10 mg/kg. However, a method with improved sensitivity and reproducibility is urgently needed to obtain a valid data basis for minimization efforts. To cope this problem a new method was created in 2020. The method was established as the standard method DGF C-VI 22 (20) of the German Society for Fat Science e.V. (DGF). For the development of this method different sample epoxidation approaches have been performed, evaluated and improved. Additionally, a saponification, a decision tree for sample preparation, an upstream clean-up column and a system suitability test were introduced. The focus was on reliability and interlaboratory comparability over all edible oil matrices up to a LOQ of 1 mg/kg. The optimized method was validated in terms of trueness and precision in a collaborative trail with 11 laboratories. The achieved recovery rates of 89-105% MOSH and 70-105% MOAH met the JRC requirements. Method and validation results were obtained with HorRat values between 1.3 and 1.8 for MOSH and MOAH.

The role of comprehensive two-dimensional gas chromatography in mineral oil determination

Mineral oil hydrocarbons (MOH) contain a wide structural diversity of molecules, for which the reference method of analysis is the online coupled liquid chromatography-gas chromatography with flame ionization detection (LC-GC-FID). These compounds are very heterogeneous from a toxicological viewpoint, and an accurate risk assessment when dealing with a MOH contamination can only be performed if sufficient information is available on the types of structures present (i.e., number of carbons, degree of alkylation, number of aromatic rings). Unfortunately, the separation performances of the current LC-GC-FID method are insufficient for such characterization, not even mentioning the possible coelution of interfering compounds which additionally hinder MOH determination. Comprehensive two-dimensional gas chromatography (GC × GC), while mostly used for confirmation purposes in the past, starts to prove its relevance for overcoming the weaknesses of the LC-GC method and reaching even better the analytical requirements defined in the latest EFSA opinion. The present paper therefore aims at highlighting how GC × GC has contributed to the understanding of the MOH topic, how it has developed to meet the requirements of MOH determination, and how it could play a role in the field for overcoming many of the current analytical and toxicological challenges related to the topic.

Use of paraffin oils in agriculture and beyond: back to the future

Paraffin (petroleum) oils have been used for many years for their insecticidal properties, but relatively little research had been conducted towards their introduction into the agricultural praxis, due to their potential phytotoxic effects. In the recent years, however, there has been an increased interest in petroleum-based pesticides due to their compatibility with integrated pest management (IPM) programs. Various improvements in the refinement methods have enhanced the manufacture of commercial products with many advantageous features over the original oil formulas. However, literature is still lacking of a general overview about the applicability of newly introduced commercial petroleum oils in agriculture and their compatibility with modern pest management practices. Therefore, the present work aims to depict the current status of petroleum oils in arboriculture and beyond, providing an in-depth analysis of their insecticidal properties with respect to the knowledge gained over the years about the factors responsible for the pesticidal efficacy and the phytotoxic activity of petroleum-derived oil insecticides. Moreover, commercial aspects of petroleum oil formulations and their toxicological profile to non-target organisms have also been addressed through the current legislation in EU and the USA.

Combination of Multidimensional Instrumental Analysis and the Ames Test for the Toxicological Evaluation of Mineral Oil Aromatic Hydrocarbons

Mineral oil aromatic hydrocarbons (MOAHs) include mutagenic and carcinogenic substances and are considered a potential health risk. Current methods address the total MOAH content but cannot address the actual toxicological hazard of individual components. This work presents a combined methodology closing those gaps: high-performance liquid chromatography (HPLC) coupled to gas chromatography with flame ionization detection was used to determine the MOAH content. To characterize present substance classes, comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry was applied. Preparative HPLC separated MOAHs into subgroups, which were tested with a miniaturized Ames test evaluating DNA reactivity of isolated fractions. Combining these methods allowed a correlation between present subgroups and DNA reactivity. The developed approach was applied to a mineral oil and distinguished between not DNA-reactive mono- and diaromatics and DNA-reactive tri- and polyaromatics, providing a proof of concept. Hereinafter, it will be applied to diverse sample matrices including mineral oils, food, and food contact materials.

Determining MOSH and MOAH with High Sensitivity in Vegetable Oil─A New, Reliable, and Comparable Approach Using Online LC-GC-FID─Evaluation of Method Precision Data

A method for the analysis of saturated mineral oil hydrocarbons (MOSH) and aromatic mineral oil hydrocarbons (MOAH) has been developed to improve interlaboratory precisions especially for amounts below 10 mg/kg. This approach was adopted as the standard method DGF C-VI 22 (20) of the German Society of Fat Sciences. Therefore, this method was evaluated on different edible oils containing a variety of interfering biogenic substances. The precision data were determined in an interlaboratory trial with an international group of 14 laboratories from Germany, Austria, and Italy. Good reproducible relative standard deviations for total MOSH (12.5-20.7%) and total MOAH (12.4-39.5%) as well as HorRat values ranging between 1.1 and 2.3 for total MOSH and between 0.9 and 2.6 for total MOAH have been achieved. As some matrices showed residual interferences in the MOAH fraction, these substances were further analyzed by online high-performance liquid chromatography-comprehensive two dimensional gas chromatography with time of flight mass detection.

Migration of food contact substances into dry foods: A review

A comprehensive review of the literature was performed on migration of substances from packaging materials into dry foods, specifically those with surfaces containing no free fats or oils. Historically, migration from food packaging to dry foods has been assumed to be minimal. However, several recent publications have reported concentrations of migrants into dry foods that are substantially higher than anticipated. The goal of this review is to provide a comprehensive summary of recent studies that examined migration to dry foods or dry food simulants, observe and assess common migrants, and report the highest migration values. Focusing on the packaging materials and migrants that exhibit the highest migration values, this review divided the studies into two categories: 1) analysis of food products in commercial packaging taken directly from grocery store shelves, and 2) analysis of food products and food simulants in contact with packaging or other material fortified with known quantities of a migrant. Discussions include the examination of migration testing methods, viability of different food simulants, and variables that affect migration behaviour. These include the physicochemical properties of both the migrant and food (i.e. volatility, molecular size, structure, food composition and particle size) and factors pertaining to the packaging material and the environment (i.e. temperature, humidity, and the presence of a secondary barrier). Information gaps and remaining questions are also identified and discussed.

Mineral oil saturated and aromatic hydrocarbons quantification: Mono- and two-dimensional approaches

The determination of the level of mineral oil contamination in foods is a well-known problem. This class of contaminants is generally divided into mineral oil saturated and aromatic hydrocarbons with different toxicological relevance and analytical challenges. Among the many challenges, data interpretation and integration represent an important source of uncertainty in the results provided by different laboratories leading to a variation evaluated on the order of 20%. The use of multidimensional comprehensive gas chromatography (GC × GC) has been proposed to support the data interpretation but the integration and the reliability of the results using this methodology has never been systematically evaluated. The aim of this work was to assess the integration and quantification performance of a two-dimensional (2D) software. The data were generated using a novel, completely automated platform, namely LC-GC × GC coupled to dual detectors, i.e., time-of-flight mass spectrometer (MS) and flame ionization detector (FID). From a systematic study of the failures of the two-dimensional quantification approach a novel solution was proposed for simplifying and automating the entire process. The novel algorithm was tested on ad hoc created samples (i.e. a paraffin mixture added of n-alkanes) and real-world samples proving the agreement of the results obtained by LC-GC × GC and the traditional mono-dimensional approach. Moreover, the benefits of using an entirely integrated platform were emphasized, particularly regarding the identity confirmation capability of the MS data, which can be easily translated into the 2D FID quantification feature.

The reliability of MOSH/MOAH data: a comment on a recently published article

In this article, we analyse recently published material by Koster et al. (Food Addit Contam Part A, 10.1080/19440049.2019.1678770, 2019) entitled “Mineral Oil Hydrocarbons in Foods: Is the Data Reliable?”. Koster et al. claim to have traced the reasons for laboratory failures to “deliver robust and reliable test results” for the analysis of MOSH/MOAH in some food matrices, however, a careful review revealed that this publication falls short in considering several aspects of assessing the reliability and comparability of analytical data produced by different laboratories.

Delineating the global plastic marine litter challenge: clarifying the misconceptions

Plastics, owing to their various beneficial properties (durability, flexibility and lightweight nature), are widely regarded as the workhorse material of our modern society. Being ubiquitously and increasingly present over the past 60 years, they provide various benefits to the global economy. However, inappropriate and/or uncontrolled disposal practices, poor waste management infrastructure, and application of insufficient recycling technologies, coupled with a lack of public awareness and incentives, have rendered plastic waste (PW) omnipresent, littering both the marine and the terrestrial environment with multifaceted impacts. The plastic marine litter issue has received much attention, especially in the past decade. There is a plethora of articles and reports released on an annual basis, as well as a lot of ongoing research, which render the issue either to be overexposured or misconstrued. In addition, there are several misinterpretations that surround the presence and environmental impact of plastics in the oceans and, consequently, human health, that require much more critical and scientific thinking. This short communication aims at unveiling any existing misconceptions and attempts to place this global challenge within its real magnitude, based either on scientific facts or nuances. Graphical abstract.