11th World Congress on Biotechnology and Biotech Industries Meet
Bonn-Rhein-Sieg University of Applied Sciences, Germany
Title: Lignin: A natural antioxidant isolated via selective extraction from lignocellulose feedstock to be used in packaging applications
Biography: Margit Ingeborg Schulze
Lignins are byproducts of the paper and pulping industry. They are available in huge amounts in form of so called black liquor, mainly produced via Kraft-pulping. However, applications of technical lignins are still limited to low-quality products due to the chemical and structural inhomogeneity. Thus, the first goal is to develop an appropriate approach for lignin extraction and purification. The purified lignins are then studied with special focus on antioxidant and bioactivity properties depending on biomass source and pulping process. In collaboration with the “Cold Chain Management” group at the University Bonn, lignin-based polymers are developed for active bio-based packaging and biomedical applications. Black liquor produced from wood pulping is used as a source of Kraft lignin. The lignin is extracted from black liquor via acidic precipitation, monitored by Thin Layer Chromatography (TLC). Purification of Kraft lignin was carried out by selective extraction. Lignins are characterized by FTIR, UV-Vis, 31P NMR, SEC, XRD and microscopy (SEM). Antioxidant activity is studied using a DPPH assay. The phenol content of lignins is determined by the Folin-Ciocalteau Micro method. Bioactivity (antibacterial and antifungal) of extracted lignins is accomplished by disk diffusion method and solution shake method. The antimicrobial activity is tested by modifying the method ISO 22196 (2007), a quantitative method to determine the level of antimicrobial activity of plastic surfaces. Folin-Ciocalteu and DPPH-Assay results confirm the antioxidant ability of lignins. In addition, it could be shown that the antioxidant activity of the lignin fractions strongly depends on the source of the black liquor. Here, differences in biomass feedstock used for the Kraft pulping process could be the reason for this observation which still is under investigation.