Seed Mineral Composition and Protein Content of Faba Beans (Vicia faba L.) with Contrasting Tannin Contents

Two-thirds of the world's population are at risk of deficiency in one or more essential mineral elements. The high concentrations of essential mineral elements in pulse seeds are fundamentally important to human and animal nutrition. In this study, seeds of 25 genotypes of faba bean (12 low-tannin and 13 normal-tannin genotypes) were evaluated for mineral nutrients and protein content in three locations in Western Canada during 2016-2017. Seed mineral concentrations were examined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the protein content was determined by Near-Infrared (NIR) spectroscopy. Location and year (site-year) effects were significant for all studied minerals, with less effect for calcium (Ca) and protein content. Genotype by environment interactions were found to be small for magnesium (Mg), cobalt (Co), Ca, zinc (Zn), and protein content. Higher seed concentrations of Ca, manganese (Mn), Mg, and cadmium (Cd) were observed for low-tannin genotypes compared to tannin-containing genotypes. The protein content was 1.9% higher in low-tannin compared to tannin-containing genotypes. The high estimated heritability for concentrations of seed Mg, Ca, Mn, potassium (K), sulphur (S), and protein content in this species suggests that genetic improvement is possible for mineral elements.