A food material nutritionally enriched in mineral composition and improved in taste includes beans or Mugi-rui enriched in magnesium, or magnesium and sodium. The Mg/K chemical equivalent ratio (a ratio of chemical equivalent of magnesium with respect to chemical equivalent of potassium) of the beans falls within the range of 0.4 to 2.0, and Mg/K chemical equivalent ratio of the Mugi-rui falls within the range of 0.8 to 3.0. The food material is manufactured by immersing the beans or Mugi-rui in aqueous solution containing magnesium chloride, or magnesium chloride and sodium chloride, at a certain concentration for a certain period of time.