Hemicelluloses from bioresidues and their applications in the food industry - towards an advanced bioeconomy and a sustainable global value chain of chemicals and materials

A major concern in the food industry is the use of non-renewable, petroleum-based materials and its detrimental impact on the environment. Consequently, there has been a growing interest in the use of biopolymers in food packaging and other applications due to their renewable origin and biodegradable properties, which have a positive environmental benefit. Hemicelluloses are biodegradable heteropolymers, which are associated with lignocellulose cell walls of vegetative and storage tissues of annual and perennial plants. They represent an immense renewable resource of biopolymers. Hemicelluloses are the second most abundant component of lignocellulosic biomass, and they are comparatively underutilized in industrial applications, even though it is a main by-product or residue in the lignocellulosic biomass processing. Therefore, it is important to include hemicellulose valorisation through the biorefinery concept to promote a Sustainable Bioeconomy (SBE), Circular Bioeconomy (CBE), and Circular Economy (CE). Extraction procedures on different plants have enabled the isolation of a diversity of hemicellulose structures with different yields and purities. However, compared to other biopolymers, their commercial uses have been underscored by their low yields, hydrophilicity, and low mechanical strength. While the applications of pure hemicelluloses are limited in the food industry, the use of hemicellulose composites as edible films, coatings, preservatives, fillers, and emulsifiers, is more promising. This review summarizes the current applications of plant hemicellulose biopolymers in the food industry and future perspectives in the advanced bioeconomy and value chain of chemicals and materials as well as ways of mitigating the challenges associated with their use.