Changes in the content of metals of strawberry after preparation of phenolic-rich and anthocyanin-rich extracts for use in biomedicine and nutrition

The importance of strawberries and some derived extracts in health is growing. So, it is necessary to have an exhaustive characterization of these food matrices that covers the different groups of molecules present in them. The composition in phenolic compounds, anthocyanins and other phytochemicals is well-known. However, so far, less attention has been paid to other compositional aspects such as those related to metals, which might be relevant in order to observe some of the effects of these extracts, since among these metals there may be significant amounts of prooxidants, cofactors of antioxidant enzymes or toxic heavy metals. Accordingly, this study was conducted on lyophilized strawberries used to obtain extracts rich in phenolic compounds or in anthocyanins. On these three products, the composition in metals analysed by ICP-MS was carried out to observe changes after the different extraction processes. Of the 15 metals analysed, and based on the levels observed in lyophilized strawberry, the concentrations of Na, Cr, Zn and Pb were higher in phenolic and anthocyanin extracts. On the other hand, both extracts showed lower levels of P, Ca, Mn, Fe, Co and Mo than the lyophilized. In the case of Cu and Y, the levels were lower in the phenolic extract, but somewhat higher in the extract rich in anthocyanins. Finally, in the case of As, the lyophilized and the phenolic extract did not show detectable levels, while some content in the extract rich in anthocyanins was appreciated. These results suggest that it is important to pay attention to the metal profile of strawberry extracts, which could be partly responsible for the effects generated by the extracts. In addition, it warns of the effects that extraction processes may have on said metal profile, which suggests that such changes should be monitored.