## 4 Discussion  
An increasing amount of research deals with the impact of plastic packaging on food and their interactions [7; 21; 22; 23; 24; 25; 26]. One of the reasons why phthalates are easily released and end up in contact environments is that they are physically, not covalently, bound to a polymer chain [27]. Phthalates do not enter food, including fish and fish products, only the contact materials in which they are packaged but also from the originating environment and the equipment with which they come into contact during processing and packaging [28]. Thus, in a study conducted in Turkey by [PERSON] [7], the phthalate content of fish packaged not only in plastic but also in cans and glass materials was analyzed in order to determine which materials released the most phthalates. It was found that the highest DEPH content of 650 \(\mathrm{\SIUnitSymbolMicro g}\)/kg was in tuna in olive oil packed in plastic packaging. [PERSON] and [PERSON] [29] proved that, in addition to the type of material, the composition of the food, as well as the conditions and length of storage, have a significant influence on the phthalate release. They investigated the migration of DBP and DEHP from packaging to meat products and found that the temperature and length of storage are very important. They also concluded that the migration of PAE was 2-21 times higher in samples with 50% fat than in samples with 10% fat. This was also confirmed in the research conducted by [PERSON] et al. [30], who found that the migration of DEHP from packaging into milk increases with increasing the temperature and is higher in dairy products with a higher percentage of fat. In this study, it can be seen that there is a migration of phthalates into fish from all the tested packaging materials, but the migration is not as high as at higher temperatures. It is expected that there was no high migration of phthalates in this study, since the samples were stored at low temperatures. Low temperatures were chosen, because this is how smoked fish is most often stored, especially if the storage time is long, precisely to see how much phthalates actually migrate from the packaging to the fish. Based on the results on the phthalate levels obtained, phthalates migration was higher after six months than after three months of storage in all the analyzed materials, as could be expected. [PERSON] and [PERSON] [25] also found an increase in time-dependent migration in fish and seafood packaged in PP and polyvinyl chloride. Regarding the influence of different packaging materials on the migration of the investigated phthalates into fish meat, it can be seen that the following materials had the statistically significantly highest migration after 6 months of storage: for DIBP (in carp, it was Bio HDPE, HDPE and PAPE; in trout, PAPE, PET and HDPE; and in salmon, PAPE and PET); for DBP (in carp, it was PAPE, Bio HDPE and HDPE; in trout, Bio HDPE, PET, PAPE, PET and LDPE; and in salmon,  
Figure 3: Levels of DHPE (\(\mathrm{\SIUnitSymbolMicro g}\)/kg) in smoked carp, trout and salmon after 6 months of storage in different packages. PAPE and PET) and for DEHP (in carp, it was Bio HDPE, PET and PAPE; in trout, it was HDPE and PET; and in salmon, Bio HDPE and PAPE). The lowest phthalate migration was observed in fish packed in PP. Migration from packaging to food occurs most often due to diffusion or adsorption [31], and it depends on a number of factors, such as the structure of the phthalate ester side chain, the fragmentation of a certain material, the microplastic particle size, the proximity of the contact between the material and the packaging and others. [PERSON] and [PERSON] [32] found that the leaching of phthalates from the smallest analyzed fraction was more than with the largest fraction tested. In this investigation, PAPE was one of the materials with the highest migration rate. This was most probably influenced by the fact that the fish in it was packed in a vacuum package and thus was in close contact with the material over almost the entire surface.