Extraction and Evaluation of Bioactive Compounds from Immature and Mature Corn Silk

Abstract

The purpose of this research was to assess the mineral content, bioactive compounds, α‐glucosidase inhibitory activity, and antioxidant of two‐maturity stages of corn silks, i.e., immature and mature with standard methods. Corn silks have been dried with sun and oven‐drying methods and extracted through methanol and water, two individual solvents. The results revealed that both corn silks were good sources of mineral content. The higher calcium (13.37 ± 0.06) and magnesium (890.00 ± 0.00) were found in the sun‐dried immature corn silk. The sun‐dried mature corn silk also exhibited a higher content of iron, zinc, and manganese. The results also revealed that all the extraction systems yielded significant amounts of TPC, TFC, β‐carotene, and anthocyanin content; ABTS and DPPH radical scavenging activity; and α‐glucosidase inhibitory activity. Moreover, sun‐dried methanolic extracts exhibited the highest levels of TFC (127.58 ± 7.95 mg QE/100 g DM), β‐carotene (0.28 ± 0.00 mg/100 mL), TAC (42.53 ± 1.02 mg C3GE/kg DM), DPPH (75.65 ± 2.38%), and ABTS (94.22 ± 0.00%), showcasing their superior antioxidant potential. Conversely, oven‐dried methanolic extracts demonstrated a higher TPC of 20.82 ± 0.62 mg GAE/g DM, while water extracts showed maximum α‐glucosidase inhibitory activity of 76.19 ± 0.00%. Therefore, the obtained results demonstrated that sun‐dried methanolic extracts from corn silks might be a good source of therapeutic agents and natural ingredients for manufacturing food, feed, and pharmaceutical products. It could also encourage researchers to carry out more studies to commercialize corn silk.