Macro and trace element mineral composition of six hemp varieties grown as microgreens

Microgreens are an increasingly popular type of nutritionally dense green leafy vegetables. Being eaten raw, they can contribute to a healthier diet being a rich source of essential nutrients such as minerals, vitamins, and bioactive metabolites. This study reports for the first time the mineral profile, obtained by ICP-OES (20 elements plus nitrate), of six hemp varieties grown as a microgreen. Moreover, we evaluated the bioaccumulation capacity of heavy metals. The data indicated that hemp microgreens are above all a good source of K (22.2 ± 2 mg kg−1 fw; mean ± s.e.) and Ca (12.6 ± 2 mg kg−1 fw), among the macrolements, and Fe (145.1 ± 4 μg kg−1 fw) and Zn (10.4 ± 0.4 μg kg−1 fw), among the microelements. Considering the RDA, microgreens are particularly valuable in meeting the nutrient requirement of Se (on average, 33.9 % of the RDA). Moreover, although hemp is being associated with soil bioremediation, microgreens do not have a notable tendency to accumulate toxic heavy metals in the edible fraction. Our results highlighted the ample variation among cultivars and imply that in our controlled conditions the genetic factor has a predominant role in establishing the elemental profile. Our study indicates that hemp microgreens can provide a rich and specific contribution of mineral elements to the human diet, and it paves the way for the exploitation of this industrial crop in the lucrative microgreen sector.