@article{AlzagameemElKhaldiHansenBuechneretal.2018,
  author    = {Abla Alzagameem and Basma El Khaldi-Hansen and Dominik B{\"u}chner and Michael Larkins and Birgit Kamm and Steffen Witzleben and Margit Schulze},
  title     = {Lignocellulosic Biomass as Source for Lignin-Based Environmentally Benign Antioxidants},
  series   = {Molecules},
  volume    = {23},
  number    = {10},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1420-3049},
  doi       = {10.3390/molecules23102664},
  url       = {https://nbn-resolving.org/urn:nbn:de:hbz:1044-opus-42057},
  year      = {2018},
  abstract  = {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.},
  language  = {en}
}