Effect of Solvent Polarity on Total Flavonoid and Phenolic Contents and Antioxidant Activity of Sweet Corn Cob (Zea mays L.) Waste Extracts

Corn cob waste is an agricultural by-product that has not been optimally utilized. This study aims to determine the flavonoid, phenolic, and antioxidant levels of corn cob extract extracted using the maceration method with n-hexane, ethyl acetate, and 70% ethanol. The test was carried out using the colorimetric method, where Folin-Ciocalteu acted as a phenolic reagent. The results showed that corn cob extract with 70% ethanol solvent had the highest total phenolic content of 455.09 ± 16.97 mg GAE/g extract. The flavonoid content of the 70% ethanol extract also showed the highest result of 179.38 ± 0.95 mg GAE/g extract. The highest antioxidant capacity was obtained in the extract with ethyl acetate solvent at 71.36 ± 0.18 µmol/g extract. Statistical analysis showed a significant difference. In conclusion, the type of solvent plays an important role in determining the levels of extracted bioactive compounds. Corn cobs have the potential to be a source of natural antioxidants that can be utilized in the cosmetics industry.