Characterization and antioxidant activity analysis of purified lignin from enzymatic hydrolysis residue of corn straw

摘要

In this work,the purified enzymatic hydrolysis lignin(EHL)was isolated from enzymatic hydrolysis residue(EHR)by neutral solvent composed of 1,4-dioxane and water(3:1,v/v)with ultrasound.The obtained EHL was then characterized by FTIR,GPC,and 1H NMR and further evaluated as potential antioxidants.The results showed that the yield of EHL was 32.7％and the purity increased from 59.2％to 74.8％by elimination of carbohydrates and protein impurities.The antioxidant activity analysis showed that the IC50 on DPPH radicals scavenging rate and prussian reduction ability changed from 0.348 g/mL and 0.301/(0.3 mg/mL)to 0.193 g/mL and 0.406/(0.3 mg/mL)after purification,respectively,which indicated that carbohydrates and protein impurities had negative effects on the antioxidant activity.The study therefore suggested that purified enzymatic hydrolysis lignin was a potential source of value added antioxidants.