Metabolome and Essential Element Analyses of Five Underutilized European Crops Reveal Their Nutritional Properties and Potential to Diversify the European Food System

<b>Background/Objectives:</b> People in the developed world tend to consume food that is rich in calories but lacks sufficient nutrients such as essential minerals, vitamins, and other health-promoting metabolites. At the same time, hunger and malnutrition are still problems in other countries. Therefore, various forms of micronutrient deficiencies and diseases caused by unbalanced nutrition are global issues. <b>Methods:</b> In order to elucidate the beneficial potential of alternative food sources, we employed state-of-the-art UHPLC-MS and ICP-MS technologies to perform comprehensive metabolome and metallome analyses of five edible European plants, some of which are known as underutilized crops: <i>Achillea millefolium</i>, <i>Agastache rugosa</i>, <i>Cercis siliquastrum</i>, <i>Crithmum maritimum</i>, and <i>Mespilus germanica</i>. <b>Results:</b> This study reveals valuable nutritional properties such as high levels of essential amino acids, sugars, organic acids, health-promoting secondary metabolites, and essential microelements that are important for human diet. The analyzed samples indicate that <i>A. millefolium</i>, <i>C. siliquastrum</i>, and <i>M. germanica</i> could be marked as a viable source of beneficial flavonoids. In turn, both leaves and fruits of <i>A. rugosa</i> had elevated abundances of organic acids, along with <i>A. millefolium</i> and <i>C. siliquastrum</i>. Similar results were observed for amino acids. <b>Conclusions:</b> Taken as a whole, the fruits of <i>C. siliquastrum</i> could be described as the best source for most of the identified compounds. The <i>M. germanica</i> samples were rich in mineral contents, with indications that they can supply 26% of the recommended daily intake per 100 g for K, 16% for Mg, 26% for Fe, 63% for Mn, and 89% for B. The leaves of <i>C. maritimum</i> and <i>A. millefolium</i> are also a good source of K and Mn. Interestingly, the sampled leaves of <i>C. maritimum</i> contained a very high amount of B, representing more than three times the reference nutrient value for 100 g of plant material. In conclusion, these underutilized species can be used to diversify the European food systems by enriching our diets with essential nutrients and health-promoting metabolites.