173
© Springer Nature Switzerland AG 2021
A. Gani, B. A. Ashwar (eds.), Food biopolymers: Structural, functional
and nutraceutical properties, https://doi.org/10.1007/978-3-030-27061-2_7
Arabinoxylans
Asima Shah, F. A. Masoodi, Asir Gani, Adil Gani, Zanoor ul Ashraf,
Nairah Noor, and Aala Fazli
Occurrence and Structure
Arabinoxylansare non-starch polysaccharides mainly localized in the endosperm
cell walls, aleurone layer and the pericarp of cereal grains (Ayala-Soto et al. 2016).
They are the pentose sugars made of arabinose and xylose and hence are often
referred to as pentosans (Izydorczyk and Bilideris 2000). Arabinoxylans have been
found in cereals, like rye, wheat, barley, oats, rice, corn, sorghum, and millets
(Izydorczyk and Biliaderis 1995; Roubroeks et al. 2000; Sun et al. 2004). Among
cereals rye has been reported as richest sources of arabinoxylans ranging between
8.2 and 10.0% (Nilsson et al. 1997). Sapirstein et al. (2013) reported total pentosan
content in four Canadian whole grain wheat cultivars within the range from 5.45 to
6.72%. A positive relationship was found between the amount of arabinoxylan
accumulated in wheat and the dry conditions (Coles et al. 1997). The total arabinoxylan content in ten covered and six naked barley cultivars ranged between 4.8 and
9.7% (Oscarsson et al. 1996). Aman (1987) reported an average arabinoxylan content of 6.9% in oats. Arabinoxylans have been reported in other sources such as
linseed mucilage, rye grass, pangola grass, psyllum, banana peels and Ispaghula
seed husk.
Pentosans from various cereals have similar molecular structures. However, they
differ in the degree of polymerization, sequence of glycosidic linkages and their
proportions, ratio of arabinose to xylose residues, pattern of substitution of the xylan
backbone with arabinose residues and the number of other substituents, such as feruloyl groups or glucuronic acid residues (Izydorczyk and Biliaderis 1995). The pentosan structure mainly consists of β-(1→4)-D-xylopyranose units which forms the
backbone to which arabinofuranose units are attached as side branches on C (O)-2
and/or C (O)-3 positions (Carvajal-Millan et al. 2007). The ratio arabinose to xylose
A. Shah · F. A. Masoodi (*) · A. Gani · Z. ul Ashraf · N. Noor
Department of Food Science and Technology, University of Kashmir,
Srinagar, Jammu and Kashmir, India
© Springer Nature Switzerland AG 2021
A. Gani, B. A. Ashwar (eds.), Food biopolymers: Structural, functional
and nutraceutical properties, https://doi.org/10.1007/978-3-030-27061-2_7
Arabinoxylans
Asima Shah, F. A. Masoodi, Asir Gani, Adil Gani, Zanoor ul Ashraf,
Nairah Noor, and Aala Fazli
Occurrence and Structure
Arabinoxylansare non-starch polysaccharides mainly localized in the endosperm
cell walls, aleurone layer and the pericarp of cereal grains (Ayala-Soto et al. 2016).
They are the pentose sugars made of arabinose and xylose and hence are often
referred to as pentosans (Izydorczyk and Bilideris 2000). Arabinoxylans have been
found in cereals, like rye, wheat, barley, oats, rice, corn, sorghum, and millets
(Izydorczyk and Biliaderis 1995; Roubroeks et al. 2000; Sun et al. 2004). Among
cereals rye has been reported as richest sources of arabinoxylans ranging between
8.2 and 10.0% (Nilsson et al. 1997). Sapirstein et al. (2013) reported total pentosan
content in four Canadian whole grain wheat cultivars within the range from 5.45 to
6.72%. A positive relationship was found between the amount of arabinoxylan
accumulated in wheat and the dry conditions (Coles et al. 1997). The total arabinoxylan content in ten covered and six naked barley cultivars ranged between 4.8 and
9.7% (Oscarsson et al. 1996). Aman (1987) reported an average arabinoxylan content of 6.9% in oats. Arabinoxylans have been reported in other sources such as
linseed mucilage, rye grass, pangola grass, psyllum, banana peels and Ispaghula
seed husk.
Pentosans from various cereals have similar molecular structures. However, they
differ in the degree of polymerization, sequence of glycosidic linkages and their
proportions, ratio of arabinose to xylose residues, pattern of substitution of the xylan
backbone with arabinose residues and the number of other substituents, such as feruloyl groups or glucuronic acid residues (Izydorczyk and Biliaderis 1995). The pentosan structure mainly consists of β-(1→4)-D-xylopyranose units which forms the
backbone to which arabinofuranose units are attached as side branches on C (O)-2
and/or C (O)-3 positions (Carvajal-Millan et al. 2007). The ratio arabinose to xylose
A. Shah · F. A. Masoodi (*) · A. Gani · Z. ul Ashraf · N. Noor
Department of Food Science and Technology, University of Kashmir,
Srinagar, Jammu and Kashmir, India