Microwave-assisted organic acid extraction of lignin from bamboo: Structure and antioxidant activity investigation

► Bamboo lignin was extracted by microwave heating assisted by organic acids. ► Increasing extraction severity resulted in increased phenolic hydroxyl content. ► The extracted lignin had antioxidant activity higher than BHT. ► Extraction at 109 °C for 60 min resulted in a lignin yield of 17.98%.