Elemental analysis and enzymes inhibitory potential of the soybean and soy products available in Nepal

The production and consumption of soybean and soy products, characterized by high nutritional values are augmenting. Particularly, Asians consume soy foods on daily basis in several forms. In this study, we evaluated the elemental contents, phenolics, antioxidants, and enzyme inhibitory potential of white soybean, black soybean, brown soybean, tofu, and soya chunks collected freshly from the agricultural field and Nepali market. Metal ions content was analyzed by the direct air-acetylene method. Antioxidant potential was evaluated by DPPH scavenging and Ferric Ion Reduction Assay. Enzymes; alpha-glucosidase, tyrosinase, acetylcholinesterase, and butyrylcholinesterase inhibition were evaluated by using specific substrates. Among the analyzed soybeans and soy products, soya chunks revealed the highest amount of sodium (Na), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), and chromium (Cr). Three principal components are defined by 97% variance with a major contribution of potassium (K), Mg, Fe, Cr, cadmium (Cd), and Cu. The methanol (80%) and ethanol (50%) extracts exhibited noteworthy flavonoids and phenolic content. Moreover, these crude extracts showed substantial antioxidant potential with a maximum of 62.17 ± 1.28% DPPH scavenging and 65.80 ± 0.24% ferric ions reduction. Further, the examined extracts revealed the noteworthy α-glucosidase, tyrosinase, acetylcholinesterase, and butyrylcholinesterase inhibition with highest of 71.54 ± 0.09, 78.85 ± 2.42, 73.04 ± 0.25, and 56.16 ± 0.06% inhibition correspondingly. Among the analyzed samples, tofu revealed essential elemental content and revealed good enzyme inhibitory potential. Among the analyzed soy sample, soy chunk extracts revealed relatively weak biological activities evident by least radical scavenging and enzyme inhibition. This study revealed the potential of soybeans and soy products in antioxidant and enzyme inhibition. Further study on the molecular mechanism underlying these activities is recommended.