Adsorbents pectin

Experiments on interactions of polysaccharides with casein micelles show similar trends to those with casein-coated droplets. For example, Maroziene and de Kruif (2000) demonstrated the pH-reversible adsorption of pectin molecules onto casein micelles at pH = 5.3, with bridging flocculation of casein micelles observed at low polysaccharide concentrations. In turn, Tromp et al. (2004) have found that complexes of casein micelles with adsorbed high-methoxy pectin (DE = 72.2%) form a self-supporting network which can provide colloidal stability in acidified milk drinks. It was inferred that non-adsorbed pectin in the serum was linked to this network owing to the absence of mobility of all the pectin in the micellar casein dispersion. Hence it seems that the presence of non-adsorbed pectin is not needed to maintain stability of an acid milk drink system. It was stated by Tromp et al. (2004) that the adsorption of pectin was irreversible in practical terms, i.e., the polysaccharide did not desorb under the influence of thermal motion. 

QCM-D measurements that include dissipation allow a more accurate estimate of mass changes through application of Voigt model that takes into account the viscoelastic properties of the system. Modeling software QTools supphed by Q-Sense uses the full thick layer expressions to model the response. Here, this program has been used to estimate the mass, thickness, viscosity, and shear elastic modulus of the adsorbed pectin layer on BSA surface, with a best fit between the experimental and model/and D values. 

The following are some of the typical industrial applications for liquid-phase carbon adsorption. Generally liquid-phase carbon adsorbents are used to decolorize or purify liquids, solutions, and liquefiable materials such as waxes. Specific industrial applications include the decolorization of sugar syrups the removal of sulfurous, phenolic, and hydrocarbon contaminants from wastewater the purification of various aqueous solutions of acids, alkalies, amines, glycols, salts, gelatin, vinegar, fruit juices, pectin, glycerol, and alcoholic spirits dechlorination the removal of... 

Littoz F and Mcclements DJ. 2008. Bio-mimetic approach to improving emulsion stability Cross-linking adsorbed beet pectin layers using laccase. Food Hydrocolloids 22(7) 1203-1211. 

Adsorbents (such as kaolin-pectin) are used for symptomatic relief (see Table 23-4). Adsorbents are nonspecific in their action they adsorb nutrients, toxins, drugs, and digestive juices. Co administration with other drugs reduces their bioavailability. 

Locally-acting are all agents that decrease stimulation of receptors in the GI tract. A viscous formulation of local anesthetics such as lidocaine increases the threshold of receptor-activity to vomiting. Adsorbents and mucosa protective agents like kaolin and pectin, activated charcoal, bismuth subsalicylate, attapulgite and cholestyramine have similar effects. Cola Syrup and phosphorylated carbohydrate can decrease GI muscle spasm with consequently less input into the vomiting center. 

Nonspecific antidiarrheal agents may be useful in treating self-limiting diarrhea. Kaolin and pectin or chalk may adsorb noxious compounds but evidence that such adsorbents are effective is unconvincing. Disadvantages can be prolongation of the course of infection and interference with absorption of desired drugs. 

KaoUn powder and other hydrated aluminum silicate clays, often combined with pectin (a complex carbohydrate), are the most widely used adsorbent powders (e.g., Kaopectate). Kaolin is a naturally occurring hydrated aluminum silicate that is prepared for medicinal use as a very finely divided powder. The rationale behind its use in acute nonspecific diarrhea stems from its ability to adsorb some of the bacterial toxins that often cause the condition. It is almost harmless and is effective in many cases of diarrhea if taken in large enough doses (2-10 g initially, followed by the same amount after every bowel movement). The adsorbents are generally safe, but they may interfere with the absorption of some drugs from the GI tract. 

Thermodynamically unfavourable interactions between two biopolymers may produce a significant increase in the surface shear viscosity (rf) of the adsorbed protein layer. This change in surface rheological behaviour is a consequence of the greater surface concentration of adsorbed protein. For instance, with p-casein + pectin at pH = 5.5 and ionic strength = 0.01 M (Ay = 2.6 x 10 m3 mol kg-2), the surface shear viscosity at the oil-water interface was found to increase by 20-30%, i.e., rp = 750 75 and 590 60 mN s m-1 in the presence and absence of polysaccharide. These values of rp refer to data taken some 24 hours following initial protein layer formation (Dickinson et al., 1998 Semenova et al., 1999a). 

Surface shear rheology at the oil-water interface is a sensitive probe of protein-polysaccharide interactions. In particular, there is considerable experimental evidence for a general increase in surface shear viscosity of protein adsorbed layers as a result of interfacial complexation with polysaccharides (Dickinson et al., 1998 Dickinson and Euston, 1991 Dickinson and Galazka, 1992 Semenova et al., 1999a Jourdain et al., 2009). One such example is the case of asi-casein + pectin at pH = 5.5 and ionic strength = 0.01 M (Ay = - 334 x 10 cm /mol) the interfacial viscosity after 24 hours was found to be five times larger in the presence of pectin (i.e., values of 820 80 and 160 20 mN m 1 with and without pectin, respectively) (Semenova et al., 1999a). 

Ganzevles, R.A., Fokkink, R., van Vliet, T., Cohen Stuart, M.A., de Jongh, H.H.J. (2008). Structure of mixed p-lactoglobulin-pectin adsorbed layers at air/water interfaces a spectroscopic study. Journal of Colloid and Interface Science, 317, 137-147. 

Adsorbents such as kaolin, pectin, or attapulgite are administered to take up and hold harmful substances such as bacteria and toxins in the intestinal lumen.44 Theoretically, these adsorbents sequester the harmful products that cause the diarrhea. These products are used frequently in minor diarrhea, although there is some doubt as to whether they really help decrease stool production and water loss. 

In summary, the QCM-D technique has successfully demonstrated the adsorption of pectin on the BSA surface as well as determined the viscoelastic properties of the pectin layer. As pectin concentrations increase, the adsorbed mass of pectin estimated from the Voigt model show higher values than those estimated from the Sau-erbrey equation because the former takes into account the hydrated layer. But the similar increase of thickness of pectin suggests that the pectin chains form a multilayer structure. In agreement with our previous rheology results, the main elastic character of the pectin layer in terms of Q-tool software tells us the network structure of the pectin layer on the BSA surface. In summary, QCM-D cannot only help to better understand the polysaccharide/protein interactions at the interface, but also to gain information of the nanoscale structure of polysaccharide multilayers on protein surface. 

Pectin has been used as an adsorbent and bulk-forming agent, and is present in multi-ingredient preparations for the management of diarrhea, constipatiom and obesity it has also been used as an emulsion stabilizer. ... 

Hydrophilic A property characterized by a strong tendency to bind or adsorb water. Examples of hydrophilic materials are carbohydrates, vegetable gums, pectins and starches, and some complex proteins such as gelatin and collagen. 

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