Four potato pectin
polysaccharides were extracted from potato
residue which had
been adopted the enzymatic removal of starch and protein by hydrochloric
acid solution , citric acid solution, alkaline phosphate solution and compound
salt solution respectively;
furthermore, ultra-filtrated, precipitate by ethanol
and lyophilized. Effect of different extraction methods on yield, the composition
characters of potato pectic polysaccharide were researched. The results show
that the bigger extraction yield, produced by alkaline phosphate and compound
salt extraction ,were 29.89% and 21.01% , respectively. The bigger galacturonic
acid content of pectic polysaccharide that was used alkaline phosphate solution
and compound salt solution were 29.71% and 31.57% , respectively. The ash
content of pectic polysaccharide that was used alkaline phosphate solution
(22.38%) is significantly higher than other three kinds of one (2.09%-2.48%).
Pectic polysaccharide extracted by four kinds of processing methods was of
low-methoxyl pectin. There was no significant difference between protein
content of four kinds of pectic polysaccharide (less than 3.0%).Galactose was
the major neutral monosaccharide units along with a small portion of arabinose,
rhamnose and glucose. The molecular weights (Mp) of four pectic polysaccharide
that was hetetopolysaccharide ranged from 1.65×104u to 1.17×106u.The
infrared spectra showed that all pectins extracted from potato had typical
functional groups of pectin. The
research has theoretical and practical significance of development and
production of potato pectin.