PENGEKSTRAKAN DAN PENCIRIAN POLISAKARIDA TERLARUTKAN AIR DARIPADA MIMOSA PYGRA L
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Date
1994-11
Authors
WILFRED, CECILIA DEVI
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Abstract
Mimosa pygra plants are found a}.)undantly in
Penang Island and are classified as weeds. To date,
there is no report on polysaccharides from Mimosa pygra
seeds. In view of this, we hav~ extracted these
polysaccharides with distilled water. Samples of Mimosa
pygra were categorised as follows: (i) young dried
seeds, (ii) young fresh seeds, (iii) old seeds, (iv)
hulls from young seeds which were later dried and (v)
cotyledons from young seeds which were later dried.
Extractions were carried out at three different
t~mperatures: 30°C, 45 °C and 60°C. Generally, the
highest percentage yield of polysaccharides from each
samples was obtained at 45 °C and the lowest at 60°C.
Based on the results from paper chromatography,
gas chromatography and nuclear magnetic resonans (NMR) ,
Mimosa pygra polysaccharides are comprised of mannose
and galactose in the average ratio of 1:1. The result
of the periodic oxidation reaction a.nd 13C NMR spectra
also show that B-(1--+4)-mannopiran" osyl formed the
backbone of the polysaccharides and this backbone
branches wi th a-'( 1--+6) -galactopiraI!osyl linkage.
It is found that Mimosa pygra polysaccharides
could increase the viscosity of an aqueous solution
$ignificantly even at low concentration. For example,
the reduced viscosity 11 sp/c (dl/g) of 0.50 g/dl of
Mimosa pygra polysaccharides solution extracted at 60°C
from sample (i) is 22.83. Combination of these
polysaccharides and xanthan in the weight ratios of
1: 1, 2: 1, 3: 1 and 4: 1 did not form gel, instead very
viscous media were obtained.
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Keywords
PENGEKSTRAKAN , PENCIRIAN POLISAKARIDA