Recent Advancements in the Valorization of Agro-Industrial Food Waste for the Production of Nanocellulose

The rising climate change concerns over the excessive exploitation of non-renewable sources have necessitated the need for alternative renewable and eco-friendly resources for the production of innovative materials, achieving the targets of bioeconomy. Lignocellulosic biomass (LB) constituted by polymeric sugars and lignin is an abundantly available plant-based renewable material in the form of agro-industrial food waste and crop residues that can be exploited for the production of an array of value-added chemicals and bioproducts. Cellulose is the most abundant natural and biodegradable organic polymer on earth derived from LB, with wide scale applications in the lignocellulosic biorefineries and food industries. The negative effects of food waste from agro-industrial activities could be reduced through the recovery of cellulose from these wastes and converting it into valuable forms. However, the extraction of cellulose from LB is a difficult task owing to the recalcitrant nature of biomass that restricts the easy accessibility of cellulose for value addition. Therefore, a suitable cellulose extraction method through the fractionation of LB is necessary for a better cellulose yield. Furthermore, owing to the enormous potential of nanocellulose (NC), researchers are keenly interested in developing ecologically acceptable cellulose extraction methods. Cellulose nanofibrils and nanocrystals confer excellent mechanical properties, non-toxic characteristics and biodegradability, due to which they possess wide-scale applications in diverse industrial sectors. The current review emphasizes the potential role of cellulose extraction and NC production from agro-food waste. The different pretreatment methods for their extraction from LB are outlined. The applications of nanocellulose in different areas are also discussed. The review also highlights the recent trends, challenges and future directions in the development of cellulose and NC-based commercial products.

Automated summary

The increasing concerns about climate change and the overexploitation of non-renewable resources have led to the need for alternative renewable and eco-friendly resources for the production of innovative materials, achieving the goals of bioeconomy. Lignocellulosic biomass (LB), derived from plant-based agro-industrial food waste and crop residues, can be utilized for the production of various value-added chemicals and bioproducts. Cellulose, derived from LB, is the most abundant natural and biodegradable organic polymer, with wide-ranging applications in lignocellulosic biorefineries and food industries. However, the extraction of cellulose from LB is challenging due to the recalcitrant nature of biomass. A suitable cellulose extraction method through LB fractionation is necessary to improve cellulose yield. Nanocellulose (NC) has great potential and researchers are interested in developing environmentally friendly cellulose extraction methods. Cellulose nanofibrils and nanocrystals have excellent mechanical properties, non-toxic characteristics, and biodegradability, making them suitable for diverse industrial sectors. This review emphasizes the potential role of cellulose extraction and NC production from agro-food waste, discusses different pretreatment methods for cellulose extraction from LB, and highlights the applications and future directions of cellulose and NC-based commercial products.