## 2 Results
### Migration and Weight Increase of GPPS and HIPS in Contact with Real Food
#### Migration and Weight Increase Using Milk, Cream and Olive Oil
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Time/Temperature** & \multicolumn{2}{c}{**Relative Migration [\%] into Milk (3.5\% Fat)**} & \multicolumn{2}{c}{**Migration of**} & **Weight Increase** \\  & **Toluene** & **Chlorobenzene** & **Styrene** & **Styrene [ug/kg]** & **[\%]** \\ \hline
15 d/20 \({}^{\circ}\)C & 1.7 \(\pm\) 0.3 & 2.8 \(\pm\) 0.2 & 2.2 \(\pm\) 0.2 & 91 \(\pm\) 7 & 0.1 \\
20 d/20 \({}^{\circ}\)C & 1.6 \(\pm\) 0.1 & 2.5 \(\pm\) 0.1 & 1.8 \(\pm\) 0.1 & 79 \(\pm\) 6 & 0.2 \\
30 d/20 \({}^{\circ}\)C & 2.5 \(\pm\) 0.5 & 3.7 \(\pm\) 0.6 & 2.8 \(\pm\) 0.5 & 118 \(\pm\) 16 & 0.1 \\
40 d/20 \({}^{\circ}\)C & 2.5 \(\pm\) 0.4 & 3.7 \(\pm\) 0.4 & 2.6 \(\pm\) 0.3 & 111 \(\pm\) 14 & 0.2 \\
60 d/20 \({}^{\circ}\)C & 3.3 \(\pm\) 0.1 & 4.8 \(\pm\) 0.1 & 3.4 \(\pm\) 0.1 & 145 \(\pm\) 5 & 0.1 \\
10 d/0 \({}^{\circ}\)C & 3.4 \(\pm\) 0.2 & 4.6 \(\pm\) 0.3 & 3.6 \(\pm\) 0.3 & 152 \(\pm\) 13 & 0.1 \\ \hline \hline  & \multicolumn{2}{c}{**Relative Migration [\%] into Cream (30\% Fat)**} & \multicolumn{2}{c}{**Migration of**} & **Weight Increase** \\  & **Toluene** & **Chlorobenzene** & **Styrene** & **Styrene*  
\hline \hline \end{tabular}
\end{table} 
Table 3: Relative migration [%] of volatiles, migrated amount of styrene in real foods and weight increase [%] of the polymer at the tested time/temperature conditions from HIPS. 2.3.2 Weight Increase of the Polymers after Contact with Several Foods under Real Application of Use  
In order to achieve better understanding of the weight increase on GPPS and HIPS polymers eventually caused by real foods under real application conditions, several additional foods and the synthetic tricglyceride Miglyol\({}^{\circledR}\)812 were investigated at storage at 5 \({}^{\circ}\)C resp. 20 \({}^{\circ}\)C for 10, 20, 30 and 50 days using the GPPS and HIPS test samples (Table 4). As expected dry foods, like ground coffee beans, oat flakes or wheat loops do not cause a significant weight increase at all (\(<0.1\%\)). In case of contact with fatty food, such as lard, butter or fish oil, a slight weight increase (\(<1\%\)) was observed. It should be noted that cleaning the polymer strips after the fatty food contact was more difficult than for the other foods. This could be also a possible reason for the higher recorded weight for the HIPS polymer samples after contact with fatty food. The weight increase recorded after contact with Miglyol\({}^{\circledR}\)812, which is an alternative food simulant for olive oil, was in the range of 4-8%. This weight increase was higher compared to olive oil and in case of HIPS even higher than the alternative food simulants 95% ethanol and isooctane tested under the same conditions at 20 \({}^{\circ}\)C. In case of GPPS the weight increase was higher using 95% ethanol and isooctane compared to Miglyol\({}^{\circledR}\)812. In Table 5 the weight increase (%) of GPPS and HIPS after contact with water at different temperatures as well as with brewed coffee is reported. Measurements were made during cooling process at ambient temperature (after 10, 20 and 30 min) and, in case of hot coffee, also at constant temperature of 100 \({}^{\circ}\)C. Except for brewed coffee (100 \({}^{\circ}\)C) that reached maximum weight increase of 1.2% with HIPS, all other results were below 1%. In contact with hot coffee at constant temperature of 100 \({}^{\circ}\)C as well as at filling at 90 \({}^{\circ}\)C and subsequent cooling, the weight increase of HIPS was equal to 0.4% after 10 min and