Pectinic acid amide

Endo-PL was found to be inactive on pectate, pectic acid amide and glycolester of pectate endo-PALs have similar activity on glycolesters of pectate as on the methylesters. Activity on glycolesters of pectate was therefore suggested as a criterion to distinguish between pectin and pectate lyases (27,34). 

Racape, E., Thibault, J.F., Reitsma, J.C.E. and Pilnik, W. 1989. Properties of amidated pectins II. Polyelectrolyte behaviour and calcium binding of amidated pectins and amidated pectic acids, Biopolymers, 28 f435-f448. 

Pectins " are high molecular weight polysaccharides with at least 65 wt% of a-(1 4)-linked d-galacturonic acid-based units, which may exist as free acid, salt (calcium, sodium, potassium, ammonium, etc.), naturally esterified with methanol, or as acid amide in ami-dated pectins. 

Definition Obtained from high ester pectin when ammonia is used in alkaline deesterification some of the remaining carboxylic acid groups have been transformed into the acid amide Uses Emuisifier, stabiiizer, thickener, gellant in foods... 

The Fourier Trairsform Infrared (FTIR) spectrum obtained from non-adapted tomato cell walls is very similar to that from the onion parenchyma cell wall (both contain cellulose, xyloglucan and pectin) although there is more protein in the tomato walls (amide stretches at 1550 and 1650 cm-i) (Fig 4). In DCB-adapted tomato cell walls, the spectrum more closely resembles that of either purified pectins or of a commercial polygalacturonic acid sample from Sigma with peaks in common at 1140, 1095, 1070, 1015 and 950 cm-t in the carbohydrate region of the spectrum as well as the free acid stretches at 1600 and 1414 cm-i and an ester peak at 1725 cm-k An ester band at 1740 cm-i is evident in both onion parenchyma and non-adapted tomato cell wall samples. It is possible that this shift in the ester peak simply reflects the different local molecular environment of this bond, but it is also possible that a different ester is made in the DCB-adapted cell walls, as phenolic esters absorb around 1720 cm-i whilst carboxylic esters absorb at 1740 cm-k The... 

Matia-Merino, L., Lau, K., Dickinson, E. (2004). Effects of low-methoxyl amidated pectin and ionic calcium on rheology and micro structure of acid-induced sodium caseinate gels. Food Hydrocolloids, 18, 271-281. 

The plots of the intensities of selected characteristic bands as a function of lateral position (so-called chemical maps) provide information on the amount of the respective molecules or molecular groups in the different morphological structures (Fig. 4.2). The band at 784 cm 1 can be assigned to out-of-plane deformation vibrational modes of the nucleobases cytosine, thymine and uracil and serves as an indicator for the presence of nucleic acids. At 483 cm-1, a C-C-C deformation of carbohydrate polymers such as starch or pectin is present in some of the spectra. To study the distribution of protein compounds, we analysed characteristic signals of the amino acid phenylalanine (1002 cm 1 ring breathe) as well as of the protein amide I band (1651 cm-1) that is brought about by vibrations of the protein backbones. The maximum of the phenylalanine signal co-localizes with a maximum in protein content... 

Note The following Requirements and Tests apply to the Pectins as supplied, whether standardized or not, except for specifications covering amide substitution and the weight percent of total galacturonic acid in the Pectin component, in which cases the test procedures include provisions for removing the sugars and soluble salts before analysis of the Pectin component. 

Degree of Amide Substitution and Total Galacturonic Acid in the Pectin Component... 

Revision Correction made to Degree of Amide Substitution and Total Galacturonic Acid in the Pectin Component Heavy Metals (as Pb) specification and determination deleted. 

Capel F., Nicolai T., Durand D., Boulenguer R, Langendorff V. (2006). Calcium and acid induced gelation of (amidated) low methoxyl pectin. Fog Jf j gggflQid, 20,901-907. 

Oat gum Oleic acid Palm glyceride Pectin Pectin, amidated... 

Gum ghatti Hydrogenated tallow glyceride Hydrolyzed oat flour Hydroxypropylcellulose Hydroxypropyl distarch glycerol Hydroxypropyl distarch phosphate Hydroxypropyl methylcellulose Hydroxypropyl starch Karaya (Sterculia urens) gum Konjac flour Lauryl betaine Locust bean (Ceratonia siliqua) gum Malt extract D-Mannitol Methylcellulose Methyl ethyl cellulose Mono- and diglycerides, of fatty acids ,Oat gum Pectin Pectin, amidated... 

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