Lignin-based materials with antioxidant and antimicrobial properties

In the literature, a variety of factors have been found to affect the antioxidant, antifungal, and antimicrobial properties of lignin: origin of the extracted lignin, particle size, shape, surface chemistry, charge, type of tested microorganisms. Due to this specific activity, lignins can be applied to stabilize food and feedstuff, commodity products with antioxidant or antimicrobial properties (sunscreen lotions, biocomposites, textiles). Thus, the aim of this chapter is to present the most relevant and current research concerning the biological activity of technical lignins, as well as lignin-based materials as a function of lignin key main parameters. The most relevant applications of the biological activity of lignins at both micro- and nanoscale are also highlighted, considering their response when included in different polymeric matrices. Their role in the antioxidant, antimicrobial, antimutagenic, antiinflammatory, and antiviral overall performance of the produced materials is extensively revised, highlighting their determinant influence in different application sectors such as biomedical, food, and plant protection.