Chemistry Reference
In-Depth Information
Fig. 5.2
Chemical structure of locust bean gum
5.2.1.3 Cassia Gum
Cassia
is a common annual plant grown in tropical countries and is abundantly
available in India. The plants of genus
cassia
are known to possess medicinal value
and are a good source of mucilages, flavonoids, anthraquinones, and
polysaccharides [
45
,
46
].
C. javahikai
(N.O. leguminosease) is a tree cultivated in
gardens as ornamental plant. The seed gum of
C. javahikai
was investigated
extensively for its potential as a coagulant in textile wastewater treatment
[
24
,
35
].
Cassia
gum is a nonionic water soluble galactomannan isolated from
endosperm of the
C. javahikai
seeds, with a molar ratio of galactose to mannose,
1:2. Seed gum has a branched structure consisting of a linear chain of
β
-(1-4)-
linked mannopyranosyl units with
D
-galactose side chains attached through
-(1-6)
linkage to the main chain [
47
]. It is very similar with LBG and GG in structure and
chemical characteristics. Cinnamon gum is suitable to form gel with other colloid
production and show potential applications in foods as a thickener, emulsifier, foam
stabilizer, and insurance agent [
48
,
49
]. The usage amount is the same as LBG and
GG. Cassia gum is a yellowish gray powder-like substance with a unique fruit-like
flavor, which can dissolve in cold water to form a colloid solution and form a
hydrocolloid after boiling. The pH value of 5 % solution is 6.5-7.5.
Cassia gum was isolated by extracting the dried crushed seeds with light
petroleum and ethanol to defat and decolorize, respectively. Then, the seed was
extracted with 1 % aqueous acetic acid and the solution was added slowly to large
excess of ethanol. The crude gum was collected, washed with ethanol, and dried
(yield 3.2 g/100 g). The crude gum was purified through the method similar with the
GG [
50
].
α
5.2.1.4 Konjac Glucomannan
KGM is a type of neutral heteropolysaccharide extracted from tubers of
Amorphophallus konjac C. Koch
. Chemically, KGM has
4)-linked
D
-man-
nose and
D
-glucose units in a molar ratio of 1.6:1 as the main chain, with branches
joined through C-3 of the
D
-glucosyl and
D
-mannosyl residues and a low number of
β
-(1
!
