94
polysaccharides from mushrooms demonstrated antitumor activities and have massive markets in East Asian countries, including Japan, and Korea (Ooi and Liu
2000). β-glucans prevent diabetes mellitus by controlling blood glucose levels and
high blood pressure (Chen and Raymond 2008). In addition, β-glucans promote
wound healing and alleviate ischaemic heart injury.
Apart from aforementioned health benefits, β-glucan may even be a valuable
ingredient in food applications. It is perceived as a non-caloric thickener for various
foods because of its viscosity (Limberger-Bayer et al. 2014). Moreover, it is utilized
in foams and emulsions as a stabilizing agent (Lazaridou and Biliaderis 2007), a
texturizing agent (Kodama et al. 2015), a fat replacer (Pintado et al. 2016) and as a
wall material for controlled release and targetted delivery of nutraceutical compounds (Wani et al. 2016).
The acceptance of β-D-glucan as functional, bioactive ingredients has increased
its popularity over the last two decades (Lazaridou and Biliaderis 2007). However,
the extraction and purification of β-D-glucan involves a complex process, thus it
needs a special attention to take advantage of its recovery and functional properties.
In this context, this chapter outlines classification, isolation, purification, modifications, neutraceutical properties and recent advances in the application of beta-glucan.
Classification, Isolation and Purification
Classification
The solubility of β-glucans is related to the degree of polymerization (DP). When
DP > 100, β-Glucans are completely insoluble in water. Solubility will increase as
DP decreases. Thus, on the basis of their solubility, β-Glucans can be classified as;
(a) alkali insoluble, acetic acid insoluble (1→3)-β-glucan; (b) alkali-soluble
(1→3)-β-glucan; and (c) highly branched (1→6)-β-glucan (Zekovic et al. 2005).
These properties impart a characteristic of insolubility for most β-glucans, limiting
application and extrapolation of in vitro experimental data in human beings.
Isolation
β-D-glucan, along with non-starch polysaccharides, starch, protein complex and
lipids, resides in the endosperm cell walls. This creates difficulty in extraction of
β-D-glucan (Brennan and Cleary 2005). To evaluate the physicochemical properties
of β-D-glucan, it needs an optimal extraction procedure to acquire the greatest level
of yield and purity and least change in molecular structure of β-D-glucan chains,
such as, alteration of extraction condition leads to change in β-D-glucan molecular
weight (Wang et al. 2003). To extract β-D-glucan, many methods have been
N. Jan et al.
polysaccharides from mushrooms demonstrated antitumor activities and have massive markets in East Asian countries, including Japan, and Korea (Ooi and Liu
2000). β-glucans prevent diabetes mellitus by controlling blood glucose levels and
high blood pressure (Chen and Raymond 2008). In addition, β-glucans promote
wound healing and alleviate ischaemic heart injury.
Apart from aforementioned health benefits, β-glucan may even be a valuable
ingredient in food applications. It is perceived as a non-caloric thickener for various
foods because of its viscosity (Limberger-Bayer et al. 2014). Moreover, it is utilized
in foams and emulsions as a stabilizing agent (Lazaridou and Biliaderis 2007), a
texturizing agent (Kodama et al. 2015), a fat replacer (Pintado et al. 2016) and as a
wall material for controlled release and targetted delivery of nutraceutical compounds (Wani et al. 2016).
The acceptance of β-D-glucan as functional, bioactive ingredients has increased
its popularity over the last two decades (Lazaridou and Biliaderis 2007). However,
the extraction and purification of β-D-glucan involves a complex process, thus it
needs a special attention to take advantage of its recovery and functional properties.
In this context, this chapter outlines classification, isolation, purification, modifications, neutraceutical properties and recent advances in the application of beta-glucan.
Classification, Isolation and Purification
Classification
The solubility of β-glucans is related to the degree of polymerization (DP). When
DP > 100, β-Glucans are completely insoluble in water. Solubility will increase as
DP decreases. Thus, on the basis of their solubility, β-Glucans can be classified as;
(a) alkali insoluble, acetic acid insoluble (1→3)-β-glucan; (b) alkali-soluble
(1→3)-β-glucan; and (c) highly branched (1→6)-β-glucan (Zekovic et al. 2005).
These properties impart a characteristic of insolubility for most β-glucans, limiting
application and extrapolation of in vitro experimental data in human beings.
Isolation
β-D-glucan, along with non-starch polysaccharides, starch, protein complex and
lipids, resides in the endosperm cell walls. This creates difficulty in extraction of
β-D-glucan (Brennan and Cleary 2005). To evaluate the physicochemical properties
of β-D-glucan, it needs an optimal extraction procedure to acquire the greatest level
of yield and purity and least change in molecular structure of β-D-glucan chains,
such as, alteration of extraction condition leads to change in β-D-glucan molecular
weight (Wang et al. 2003). To extract β-D-glucan, many methods have been
N. Jan et al.