PENGEKSTRAKAN DAN PENCIRIAN POLISAKARIDA TERLARUTKAN AIR DARIPADA MIMOSA PYGRA L

Loading...
Thumbnail Image
Date
1994-11
Authors
WILFRED, CECILIA DEVI
Journal Title
Journal ISSN
Volume Title
Publisher
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.
Description
Keywords
PENGEKSTRAKAN , PENCIRIAN POLISAKARIDA
Citation