103
β-glucans that ultimately modify the viscosity property of β-glucan. Generally these
enzymes initiate depolymerization reactions, resulting in low viscosities (Ahmad
and Anjum 2010; Burkus and Temelli 2000).
Moreover, final viscosity of the β-glucan can be affected by the extraction conditions. At very high pH, extraction of oat β-glucan can cause changes in β-glucan
which will lower its viscosity property. The interaction between high pH and
medium temperature is extremely unfavourable for the viscous property of β-glucan.
This is due to the sensitive nature of 1→3 linkages at higher pH levels or medium
temperatures.
Modifications
β-Glucan is taken into account as a very important bioactive compound for human
health, but its low solubility has led to the development of chemical modification
technologies to improve bioavailability. To modify β-glucan, various methods
including physical and chemical crosslinking reactions are laid out to increase their
functional and technological properties (Ahmad et al. 2015). β-glucans in this
respect can be chemically modified to obtain various derivatives with potential
industrial or medicinal applications (Synytsya and Novak 2013). Chemical modifications including sulfonylation, carboxymethylation, phosphorylation and acetylation are regarded as important tools to improve the properties, bioactivities and
applications in the structure of polysaccharides, (Tranquilan-Aranilla et al. 2012; Ye
et al. 2012; Jindal et al. 2013). Chemical derivatization of β-D-glucans improved
antioxidant, antitumoral, anticoagulating and immunomodulating activities.
Additionally, chemical characteristics can be changed by modifying β-D-glucans
which sufficiently enhance bioactivity, thereby widening their range of applications
(Magnani et al. 2009; Tranquilan-Aranilla et al. 2012; Jindal et al. 2013). Thus,
chemical modification can be a useful tool in developing β-D-glucans as therapeutic
agents (Sarangi et al. 2006; Zong et al. 2012; Zhang et al. 2013).
Chemical Modification by Sulfonylation
Sulfonated polysaccharides are complex molecules that exert excellent physicochemical properties and bioactivity. The sulfonate group is attached to the hydroxyl
group on the monosaccharide unit, thus, improves the biological activities compared to the parent non-sulfonated polysaccharides (Raveendran et al. 2013).
Sulfonylation is obtained through the reaction between pyridine and chlorosulfonic
acid or pyridine and sulfur trioxide, indimethyl sulfoxide (Carvalho et al. 2013).
Sulfonylation methods employing pyridine-chlorosulfonic acid producing greater
yields of sulfonated polysaccharides with a large degree of substitution, and more
Beta-Glucans
β-glucans that ultimately modify the viscosity property of β-glucan. Generally these
enzymes initiate depolymerization reactions, resulting in low viscosities (Ahmad
and Anjum 2010; Burkus and Temelli 2000).
Moreover, final viscosity of the β-glucan can be affected by the extraction conditions. At very high pH, extraction of oat β-glucan can cause changes in β-glucan
which will lower its viscosity property. The interaction between high pH and
medium temperature is extremely unfavourable for the viscous property of β-glucan.
This is due to the sensitive nature of 1→3 linkages at higher pH levels or medium
temperatures.
Modifications
β-Glucan is taken into account as a very important bioactive compound for human
health, but its low solubility has led to the development of chemical modification
technologies to improve bioavailability. To modify β-glucan, various methods
including physical and chemical crosslinking reactions are laid out to increase their
functional and technological properties (Ahmad et al. 2015). β-glucans in this
respect can be chemically modified to obtain various derivatives with potential
industrial or medicinal applications (Synytsya and Novak 2013). Chemical modifications including sulfonylation, carboxymethylation, phosphorylation and acetylation are regarded as important tools to improve the properties, bioactivities and
applications in the structure of polysaccharides, (Tranquilan-Aranilla et al. 2012; Ye
et al. 2012; Jindal et al. 2013). Chemical derivatization of β-D-glucans improved
antioxidant, antitumoral, anticoagulating and immunomodulating activities.
Additionally, chemical characteristics can be changed by modifying β-D-glucans
which sufficiently enhance bioactivity, thereby widening their range of applications
(Magnani et al. 2009; Tranquilan-Aranilla et al. 2012; Jindal et al. 2013). Thus,
chemical modification can be a useful tool in developing β-D-glucans as therapeutic
agents (Sarangi et al. 2006; Zong et al. 2012; Zhang et al. 2013).
Chemical Modification by Sulfonylation
Sulfonated polysaccharides are complex molecules that exert excellent physicochemical properties and bioactivity. The sulfonate group is attached to the hydroxyl
group on the monosaccharide unit, thus, improves the biological activities compared to the parent non-sulfonated polysaccharides (Raveendran et al. 2013).
Sulfonylation is obtained through the reaction between pyridine and chlorosulfonic
acid or pyridine and sulfur trioxide, indimethyl sulfoxide (Carvalho et al. 2013).
Sulfonylation methods employing pyridine-chlorosulfonic acid producing greater
yields of sulfonated polysaccharides with a large degree of substitution, and more
Beta-Glucans