8 - Arabinoxylans from cereal by-products: Insights into structural features, recovery, and applications

Abstract

Arabinoxylans (AX) are one of the most abundant polysaccharides of cereal grain cell walls. They are nonstarch polysaccharides with viscous and water retention properties, which confer on them high nutritional impact as dietary fiber with recognized health-promoting effects. The occurrence and structure of AX can differ among cereals. Their structural heterogeneity, properties, and recovery are dependent on AX tissue location, strongly influenced by interactions with other cell wall components. As considerable interest has been shown toward cereal-processing by-products as inexpensive and rich sources of AX, various extraction methodologies such as hydrothermal, chemical, and enzymatic treatments have been proposed. These methods recover different AX structures, arabinooligosaccharides (AXOS), and sugar monomers that could be valorized in food, health, and materials fields. This chapter explores the occurrence and structural heterogeneity of AX from cereals and their by-products, discussing the main extraction approaches and their influence on the recovered structures. An overview of the current main applications for cereal by-products AX and AXOS is also presented.