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Pearlescent pigments are used as colourants to increase the attractiveness of food products, especially in the patisserie and confectionery sector. They can be seen as composite materials and consist of thin potassium aluminium silicate (E 555, mica) platelets as carrier material, coated with a thin metal oxide layer of TiO 2 (E 171) and/or iron oxides (E 172). The European Food Safety Authority stated in 2020 that mica-based pearlescent pigments as a whole should be evaluated as new food additives. Obtaining dependable data for particle size and layer thickness of these pigments is crucial both for the demanded food additive evaluation itself and also for the nanomaterial labelling assessment of products containing these food colourants according to the 'Food Information to Consumers' regulation. Since it was found in a previous study on TiO 2 -containing pearlescent pigments (silver and golden coloured) that the coating consisted of nanoscaled constituent titanium oxide particles, in this follow-up study we investigated whether Fe 2 O 3 -containing pearlescent pigments exhibit a similar nanostructured morphology. For this purpose, five commercially-available food products containing these pigments were investigated. Static light scattering and flow particle image analysis were used as screening methods to determine the mica platelet size. Scanning electron microscopy combined with energy-dispersive X-ray spectroscopy was used for nanostructure analysis of the metal oxide coating. The carrier mica platelets were 34-96 µm in diameter and 300-800 nm thick. The coating thickness was found to be in the range of 75-105 nm, with the constituent round shaped iron oxide particles contained therein having a minimum Feret diameter of 37-64 nm.

A wide range of trendy food colourants and ready-to-eat foods containing pearlescent pigments providing glitter effects is currently on the market. These pearlescent pigments consist of mica (potassium aluminium silicate) platelets generally coated with titanium dioxide and/or iron oxides. All single components are approved food additives in the European Union (EU) (E 555, E 171 and E 172). However, the European Food Safety Authority (EFSA) has stated recently, that pearlescent pigments should be evaluated as new food additives. Food grade titanium dioxide was already shown to contain a considerable fraction of nanoparticles. Thus, the question about 'nano'-labelling of TiO 2 -containing pearlescent pigments according to the 'Novel Food' and 'Food Information to Consumers' regulations arose. In order to provide data for dealing with these issues, in this study four commercially available products of different food categories containing pearlescent pigments were characterised with focus on the structure, size and chemical composition of these pigments. The measurement methods used were flow particle image analysis (FPIA), static light scattering (SLS) and scanning electron microscopy (SEM) combined with energy-dispersive x-ray spectroscopy (EDX). After isolation from various food matrices, the glitter pigments could be easily identified and differentiated by fast FPIA screening from any remaining organic food matrix particles due to their typical platelet-like shape and transparency. The particle size distribution of the platelets was determined by means of SLS and found to be in the range of 8-167 µm. SEM was identified as the most suitable technique for the analysis of the nano-structured coating. For all constituent metal oxide particles (TiO 2 and/or Fe 2 O 3 ) a median minimum Feret diameter (F min ) of 29.9-46.8 nm was obtained by quantitative SEM image analysis.

Background and Aims: Surgical resection is currently the cornerstone of liver tumor treatment in children. In adults radiofrequency ablation (RFA) is an established minimally invasive treatment option for small focal liver tumors. Multiprobe stereotactic RFA (SRFA) with intraoperative image fusion to confirm ablation margins allows treatment for large lesions. We describe our experience with SRFA in children with liver masses., Methods: SRFA was performed in 10 patients with a median age of 14 years (range 0.5-17.0 years) suffering from liver adenoma ( n  = 3), hepatocellular carcinoma ( n  = 1), hepatoblastoma ( n  = 2), myofibroblastic tumor ( n  = 1), hepatic metastases of extrahepatic tumors ( n  = 2) and infiltrative hepatic cysts associated with alveolar echinococcosis ( n  = 1). Overall, 15 lesions with a mean lesion size of 2.6 cm (range 0.7-9.5 cm) were treated in 11 sessions., Results: The technical success rate was 100%, as was the survival rate. No transient adverse effects higher than grade II (Clavien and Dindo) were encountered after interventions. The median hospital stay was 5 d (range 2-33 d). In two patients who subsequently underwent transplant hepatectomy complete ablation was histologically confirmed. Follow-up imaging studies (median 55 months, range 18-129 months) revealed no local or distant recurrence of disease in any patient., Conclusions: SRFA is an effective minimal-invasive treatment option in pediatric patients with liver tumors of different etiologies.