TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Alzagameem, Abla A1 - El Khaldi-Hansen, Basma A1 - Büchner, Dominik A1 - Larkins, Michael A1 - Kamm, Birgit A1 - Witzleben, Steffen A1 - Schulze, Margit T1 - Lignocellulosic Biomass as Source for Lignin-Based Environmentally Benign Antioxidants JF - Molecules N2 - Antioxidant activity is an essential aspect of oxygen-sensitive merchandise and goods, such as food and corresponding packaging, cosmetics, and biomedicine. Technical lignin has not yet been applied as a natural antioxidant, mainly due to the complex heterogeneous structure and polydispersity of lignin. This report presents antioxidant capacity studies completed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The influence of purification on lignin structure and activity was investigated. The purification procedure showed that double-fold selective extraction is the most efficient (confirmed by ultraviolet-visible (UV/Vis), Fourier transform infrared (FTIR), heteronuclear single quantum coherence (HSQC) and 31P nuclear magnetic resonance spectroscopy, size exclusion chromatography, and X-ray diffraction), resulting in fractions of very narrow polydispersity (3.2⁻1.6), up to four distinct absorption bands in UV/Vis spectroscopy. Due to differential scanning calorimetry measurements, the glass transition temperature increased from 123 to 185 °C for the purest fraction. Antioxidant capacity is discussed regarding the biomass source, pulping process, and degree of purification. Lignin obtained from industrial black liquor are compared with beech wood samples: antioxidant activity (DPPH inhibition) of kraft lignin fractions were 62⁻68%, whereas beech and spruce/pine-mixed lignin showed values of 42% and 64%, respectively. Total phenol content (TPC) of the isolated kraft lignin fractions varied between 26 and 35%, whereas beech and spruce/pine lignin were 33% and 34%, respectively. Storage decreased the TPC values but increased the DPPH inhibition. KW - biomass KW - kraft lignin KW - lignocellulose feedstock KW - total phenol content KW - organosolv KW - antioxidant activity KW - Folin-Ciocalteu assay UN - https://nbn-resolving.org/urn:nbn:de:hbz:1044-opus-42057 SN - 1420-3049 SS - 1420-3049 U6 - https://doi.org/10.3390/molecules23102664 DO - https://doi.org/10.3390/molecules23102664 PM - 30332854 VL - 23 IS - 10 PB - MDPI CY - Basel ER -