Title : Mineral oil hydrocarbons in commercially available rennet ripened cheeses
Abstract:
Mineral Oil Hydrocarbons (MOH) are a complex mixture of isomers derived primarily from crude oil that undergoes refining, and to a lesser extent from the coal, natural gas, and biomass. MOH split into Mineral Oil Saturated Hydrocarbons (MOSH) and Mineral Oil Aromatic Hydrocarbons (MOAH). Sources of food contamination with MOH include migration from packaging (recycled paper, release of printing inks, use of mineral oils in the production of plastics), use of jute or sisal bags, food additives such as anti-caking agents, contamination on technological lines (lubricants, diesel fuels), and contamination during harvesting (agricultural machinery). MOSH accumulates in the liver, spleen and adipose tissue and the consequences of this are not yet known. MOAH with 3 or more aromatic rings are associated with genotoxicity and carcinogenicity. Taking into account the risk assessment carried out by EFSA in 2023, discussions have started on establishing EU rules on maximum levels of MOAH and indicators of MOSH levels in food. Since the presence of MOH in food is avoidable, it is recommended that food business operators ensure that the concentrations of MOSH and MOAH in products are below the limits of detection, for example in the case of rennet cheeses <1 mg/kg (food group with a fat content of 4 to 50%).
The aim of this study was to evaluate the content of MOH in commercially available ripened rennet cheeses. The presence of various MOH fractions, i.e., MOAH and MOSH/POSH, in 45 samples of polish ripened rennet cheeses, were analyzed using coupling liquid and gas chromatography with subsequent flame ionization detection (LC-GC-FID). The influence of selected factors (packaging type, and product form, i.e. cheese in a block, cheese portioned in pieces, cheese sliced) on MOH content in the samples was assessed.
The MOSH/POSH were detected in all cheese samples, with the highest levels (1.1–17.0 mg/kg) for the C25-35 fraction in sliced cheeses. By comparison, in block cheeses, this fraction was detected in 75% of samples at 1.3–2.1 mg/kg. The C10-16 MOSH/POSH fraction was not detected in any sample, regardless of the product form (above the detection limit of 0.60 mg/kg of product). MOAH were detected primarily in sliced cheeses in 8-32% of the samples tested, and in a much smaller percentage of block cheeses (25% of the samples). The C10-16 MOAH fraction was not detected in any sample, regardless of the product form. No MOAH was detected in portioned cheeses (above the detection limit of 0.15 mg/kg of product). The contents of the C16-25, C25-35, and C35-50 MOAH fractions in sliced cheeses were 0.15-0.28, 0.16-1.2, and 0.16-0.59 mg/kg of product, respectively. Taking into account the EFSA recommendations, it can be concluded that in 4.4% of the tested samples the MOAH content was higher, and this only concerned sliced cheese samples.
Research financed by the Ministry of Science and Higher Education of Poland as part of the targeted subsidy "Research network of natural science universities for the development of the Polish dairy sector - research project" (SUP-RIM) (MEiN/2023/DPI/2866).
