A study on different storage conditions affecting mineral oils migration from packaging to semolina and egg pasta

Most foodstuffs are provided with a packaging which carries out several important functions. However, the transfer of undesirable compounds can occur during the shelf-life of the product. In particular, cardboard packaging represents an important source of food contamination with mineral oil, when recycled fibers or mineral oil based printing inks are used. In this work MOSH (mineral oil saturated hydrocarbons), MOAH (mineral oil aromatic hydrocarbons), POSH (polyolefin oligomeric saturated hydrocarbons), and DIPN (diisopropyl naphtalenes) migration from packaging to dry foods has been monitored up to 1 year, focusing on the influence of food packaging material, fat content of the food, time and storage condition. Furthermore, contribution of hot melt adhesives used to close boxes to the total contamination was also evaluated. Semolina and egg pasta, of the same small size, were packed in plastic film bags and in recycled and virgin paperboard boxes and stored under two different conditions at ambient temperature. Same samples were stored on shelves to simulate the real common storage conditions, while others were wrapped in aluminum in order to force the migration only towards pasta, excluding any external influence. The mineral oil migration from a transport box consisting of corrugated board, through the primary packaging, was also evaluated. Migration behavior was studied measuring both the mineral oil amount lost by the packaging (calculated as the difference between pre- and post-contact contamination) and the mineral oil amount migrated in pasta samples after the exposure (subtracted from the pasta contamination at time zero). Diffusion of migrated mineral oil inside the product was also monitored by applying selective extraction methods (for semolina pasta). A POSH contamination was evident in pasta samples stored in plastic film. Very low contamination levels (< 0.6 mg/kg of MOSH) were found in pasta sample packaged in virgin paper. An important contribution due to the use of hot melt adhesives was evidenced. Higher contamination levels (about 5 and 12 mg/kg of MOSH for semolina and egg pasta, respectively) were found in pasta packaged in recycled paperboard for 1 year. Samples reached a steady contamination level, already after the first 1–3 months of storage, corresponding to about 20 and 50% of potential migration for semolina and egg pasta, respectively. The contribution of the external ambient was well evident in samples stored on the shelves (especially for egg pasta), while a little contribution due to the corrugated cardboard used as secondary packaging was observed.