The underlying mechanisms governing nonenzymatic pectin and pectate degradation during thermal treatment have not yet been fully elucidated. This study determined the extent of nonenzymatic degradation due to beta-elimination, acid hydrolysis, and demethylation during prolonged heating of citrus pectins and its influence on physicochemical properties. Solutions of citrus pectins, buffered from ...

BACKGROUND AND AIMS Covalent linkages between xyloglucan and rhamnogalacturonan-I (RG-I) have been reported in the primary cell walls of cultured Rosa cells and may contribute to wall architecture. This study investigated whether this chemical feature is general to angiosperms or whether Rosa is unusual. * METHODS Xyloglucan was alkali-extracted from the walls of l-[1-3H]arabinose-fed suspens...

The aim of this study was to quantify mucilages, pectins, hemicelluloses, and cellulose of nopalitos (edible, as vegetable, young cladodes of flat-stemmed spiny cacti) of most consumed Mexican cultivars, and sweet and acid cactus pear fruits of Opuntia spp. The hypothesis is that, regardless of their unavailable polysaccharides diversity, nopalitos and cactus pear fruits are rich sources of sol...

Pectic substances have generally been thought to be the principal binding agents between plant cells (12). These pectins are considered to be largely pectic acid because the middle lamella stains with ruthenium red (8). Ginzberg (7) considers that protein and metals are also important binding agents between the cells of the root tip of Alaska pea seedlings. There is, however, a need for further...

The synthesis of pectin-silica gels for controlled drug release in gastrointestinal tract (GIT) using low methoxyl (LM) and high methoxy (HM) pectins and tetraethoxysilane (TEOS) as precursor is described. The FTIR spectra of the pectin-silica gels show intense absorption bands at 1246cm-1 and 802cm-1 corresponding to the vibrations COSi bonds, which absent in the FTIR spectra of the native pec...

Plant cell walls are important barriers against microbial pathogens. Cell walls of Arabidopsis thaliana leaves contain three major types of polysaccharides: cellulose, various hemicelluloses, and pectins. UDP-D-galacturonic acid, the key building block of pectins, is produced from the precursor UDP-D-glucuronic acid by the action of glucuronate 4-epimerases (GAEs). Pseudomonas syringae pv macul...

The presence and characteristics of cuticle polysaccharides have been demonstrated by staining and spectroscopic methods, but their location in the cuticle remains unclear. Furthermore, according to the prevailing model, polysaccharides are believed to be restricted to the cuticular layer and absent in the cuticle proper. With the aim of gaining insight into cuticular ultra-structure focussing ...