Pectin, enzymatic degradation

The plant cell wall is a polymeric mesh consisting of cellulose, hemicellulose, pectin and protein. Cellulose and hemicellulose are integral components of the cell wall, but pectic substances are located mainly in the outer wall regions within the middle lamella (McNeil et ai, 1984). Pectic substances are more susceptible to enzymatic degradation, because they are more exposed than other cell wall components. Therefore, pectin-degrading enzymes may play a central role in the penetration of plant tissue by bacteria. 

Enzymatic degradation of pectin can be satisfactory performed in UF-membrane reactors which have been proved to be helpful tool for laboratory scale investigations. Reaction products can be continuously recovered in a sequence of filtration stages. The obtained product distribution depends on the enzyme to substrate ratio, which affects particularly the... 

To date, the structural features of pectic polysaccharides and plant cell walls have been studied extensively using chemical analysis and enzymatic degradation. In addition, research on isolation and physicochemical characterisation of pectin from citrus peels, apple peels, sunflower head residues and sugar beet pulp has been reported (2). However, the pectic polysaccharides extracted from wheat straw have only previously been reported by Przeszlakowska (3). The author extracted 0.44% pectic substances from Author to whom correspondence should be addressed. 

Oligouronides production in a membrane reactor by enzymatic degradation of pectins from Citrus peel. A preliminary study... 

Specific enzymatic degradation has been useful in determining the structures of pectins, gums and other plant polysaccharides (115), the mucopolysaccharides of higher animals (116), and other complex carbohydrates (117) including those from microorganisms 118, 119, 120). In these heterogeneous polymers enzyme treatment is most useful for deter-... 

With the objective of enhancing membrane flux by enzymatic degradation of pectin in the puree, the liquefaction enzymes normally used in the process were reduced while a commercial pectinase preparation was used in increasing amounts as a replacement (Table I). 

Galacturonic acid OS [GalA(al] - 4)GalA Enzymatic degradation of pectin... 

In some beverages, such as fruit juices, beer or wine, turbidity and sediment formation can occur with the involvement of phenolic compounds, pectins and proteins. These defects can be corrected by (a) partial enzymatic degradation of pectins and proteins (b) removal of phenolic compounds with the aid of gelatin, polyamide or polyvinyl pyrrolidone powders and (c) by protein removal with bentonite or tannin. Bentonite consists of hydrous aluminium silicate. 

---