# Assessment of Bioactive Surfactant Levels in Selected Cereal Products
## 4 Conclusions  
This paper is the first cross-sectional study on the occurrence of ten perfluoroalkyl substances in widely available and consumed cereal-based products such as bread, rolls, flour, bran, buckwheat, millet, rice, and noodle. The QuEChERS method with a d-SPE purification step followed by LC-MS/MS detection was successfully applied. Throughout the trial, PFOA proved to be the most abundant compound, but individual PFBA concentrations were the highest. Five PFASs (PFBA, PFPeA, PFHxA, PFOA, and PFOS) were detected in cereal-based products, indicating that plants have the ability to take up PFAS from soils via the root system and translocate PFAS to the above-ground parts. One mechanism that is possibly responsible for the accumulation of PFAS in plant compartments, especially in protein-rich grains, is the interaction of these compounds with proteins. The preferential accumulation of C4-C7 homologs characterized by higher BAF was observed. PFAS are found in air, water, soil, vegetation, and livestock, and thus can also be found in food products if not properly regulated and managed. In terms of PFAS contamination of food items, the top quality of products should be maintained by very strict control conducted over the production process, starting with seed selection, field monitoring, processing, and final packaging. Except for PFBA, the indicated PFAS concentrations were relatively low; nevertheless, with regards to the existing TWI standards laid down by EFSA and the high level of consumption of cereal products, it is important to implement further investigations to control PFAS distribution and evaluate the environmental risks. In the future, food manufacturers should perhaps consider periodic testing of food ingredients that may be potentially contaminated with PFAS and investigate possible sources of these contaminants. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Product**} & \multicolumn{3}{c}{**Average Monthly Consumption of Selected Foodstuffs in**} \\  & \multicolumn{3}{c}{**Households [kg/capita]**} \\ \cline{2-4}  & **2010** & **2018** & **2019** \\ \hline \multirow{2}{*}{\begin{tabular}{c} Bread and cereals \\ (total) \\ \end{tabular} } & \multirow{2}{*}{7.05} & \multirow{2}{*}{5.48} & \multirow{2}{*}{5.36} \\ Rice & & & & \\ \multirow{2}{*}{\
\begin{tabular}{c} Beta \\ Pasta and pasta \\ products \\ \end{tabular} } & \multirow{2}{*}{0.37} & \multirow{2}{*}{0.38} & \multirow{2}{*}{0.40} \\ Flour & & & & \\ \multirow{2}{*}{
\begin{tabular}{c} Groats and flakes \\ \end{tabular} } & \multirow{2}{*}{0.21} & \multirow{2}{*}{0.27} & \multirow{2}{*}{0.27} \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Average monthly consumption of selected cereal products in Poland in the years 2010–2019 [58]. **Supplementary Materials:** The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/app12105242/s1](https://www.mdpi.com/article/10.3390/app12105242/s1)]([https://www.mdpi.com/article/10.3390/app12105242/s1](https://www.mdpi.com/article/10.3390/app12105242/s1)): Figure S1: The structures of the investigated analytes; Figure S2: The results of the Kruskal-Wallis H non-parametric test for detected variables (PFBA, PFPEA, PFHxA, PFOA, and PFOS); Table S1: Retention times and MRM ion pairs of analyzed PFAS; Table S2: Clustering of samples using hierarchical sample clustering analysis. **Author Contributions:** Conceptualization, M.S. and K.S.-K.; methodology, M.S. and K.S.-K.; software, W.W.; validation, K.S.-K.; formal analysis, K.S.-K. and W.W.; investigation, M.S. and K.S.-K.; resources, K.S.-K.; data curation, M.S. ; writing--original draft preparation, K.S.-K.; writing--review and editing, M.S. and H.Z. ; visualization, K.S.-K.; supervision, M.S. and H.Z. ; project administration, M.S. ; funding acquisition, M.S. All authors have read and agreed to the published version of the manuscript. **Funding:** This work was supported by project grants No. 2015/17/B/NZ9/01623 from the National Science Center, Poland.