A new pectin was extracted from the leaves of Krueo Ma Noy (Cissampelos pareira), a woody climbing plant grown in Thailand.
Optimized condition for the extraction of pectin was using the solid:solvent ratioZ1:50 in distilled water at 25–28 8C and natural pH
(3.8–4.0). A crude pectin extract was obtained after alcohol precipitation and drying; the crude extract was dialyzed and lyophilization
produced a dialyzed pectin fraction. The extracted Krueo Ma Noy pectin is a low methoxyl pectin which consisted mainly of uronic
(galacturonic) acid (w70–75%) and small amounts of neutral sugars. Krueo Ma Noy pectin exhibited shear thinning flow behavior and the
extent of shear thinning was concentration dependent. Gelation was observed when Krueo Ma Noy pectin (both crude extract and dialyzed
fractions) concentration exceeded 0.5% (w/v); gel strength of the dialyzed fraction was much higher than that of the crude extract. The
addition of NaCl significantly increased the Krueo Ma Noy pectin gel strength when salt concentration was below 0.4 M. Krueo Ma Noy
pectin was also found to be sensitive to Ca2C ions: the addition of 1 mM calcium chloride significantly increased the gel strength and
excessive amount of Ca2C (O3 mM) resulted in aggregation/precipitation of the pectin, possibly due to the calcium binding properties of the
carboxyl group. It was also observed that addition of sugar increased the gel strength of Krueo Ma Noy pectin.
q 2004 Elsevier Ltd. All rights reserved.