Applications of lignin in the agri-food industry

Of late, valorization of agri-food industrial by-products and their sustainable utilization isgaining much contemplation world-over. Globally, 'Zero Waste Concept' is promoted withmain emphasis laid towards generation of minimal wastes and maximal utilization of plantbasedagri-food raw materials. One of the wastes/by-products in the agri-food industry are thelignin, which occurs as lignocellulosic biomass. This biomass is deliberated to be anenvironmental pollutant as they offer resistance to natural biodegradation. Safe disposal of thisbiomass is often considered a major challenge, especially in low-income countries. Hence, theapplication of modern technologies to effectively reduce these types of wastes and maximizetheir potential use/applications is vital in the present day scenario. Nevertheless, in some of thehigh-income countries, attempts have been made to efficiently utilize lignin as a source of fuel, as a raw material in the paper industry, as a filler material in biopolymer based packaging andfor producing bioethanol. However, as of today, agri-food industrial applications remainssignificantly underexplored. Chemically, lignin is heterogeneous, bio-polymeric, polyphenoliccompound, which is present naturally in plants, providing mechanical strength and rigidity.Reports are available wherein purified lignin is established to possess therapeutic values; andare rich in antioxidant, anti-microbial, anti-carcinogenic, antidiabetic properties, etc.This chapter is divided into four sub-categories focusing on various technologicalaspects related to isolation and characterization of lignin; established uses of lignin; provedbioactivities and therapeutic potentials of lignin, and finally on identifying the existing researchgaps followed by future recommendations for potential use from agri-food industrial wastes.