Solubilities, polysaccharides

A traditional system for the preparation of table olives, involves a treatment of the fresh fruit with a solution of NaOH to hydrolised the bitter glycoside oleuropein, followed by a lactic fermentation in brine. The modifications that take place on pectic polysaccharides of olives (Manzanilla variety) during this process was smdied. Processing induced a net loss of polysaccharides soluble in sodium carbonate and a paralel accumulation of water and Imidazole/HCl soluble polysaccharides. A general decrease of the apparent molecular weight of water and carbonate soluble polysaccharides was also detected. 

Polysaccharide solubility in aqueous solutions usually is dependent on polymer size and its allied three-dimensional structure. Even water-insoluble carbohydrates may be solubilized by controlled hydrolysis of o-glycosidic linkages to create smaller polysaccharide molecules. Thus, cellulose may be solubilized by heating in an alkaline solution until the polymers are broken up sufficiently to reduce their average molecular weight. Many such soluble forms of common polysaccharides are available commercially. 

Conditions or procedure Insoluble polysaccharide Soluble polysaccharide ... 

Some of the most important water-soluble polymers belong to the family of polysaccharides. Soluble polysaccharides were discussed in a review by Franz on polysaccharides in pharmaceutical formulations. Due to their industrial importance, key characteristics and typical applications of those polysaccharides are listed in Table 3. In addition to those noted in Table 3, the oxidation of cellulose (to convert 16-24% of its primary hydroxyl groups to carboxyl groups) produces oxidized cellulose, a fibrous white powder. It is used as a bioabsorbable hemostatic agent. The bioabsorption may be partly attributed to solubilization through the carboxylate moieties. 

Polysaccharides Soluble in 0.5% am. oxal. Anhydrous galac-turonic acid 2.6 95 5.0 95 5.0 97... 

An underlying assumption is that dextran is a representative polysaccharide source and that results derived from studying its modification can be directly applied to other sources of polysaccharides. If dextran can be successfully modified utilizing a specific reaction system, other polysaccharides can likewise be modified using the same reaction system if that particular polysaccharide is soluble in the given reaction phase employed. Thus, polysaccharide solubility is the key factor in determining which reaction system can be employed. 

Radiation-induced main-chain degradation renders polysaccharides soluble, or at least increases their solubility, and therefore technical interests have focused on the radiation-induced main-chain degradation of certain biopolymers, such as cellulose, chitin and chitosan [96,104-107]. In being the main component of plants, cellulose is a widespread biopolymer. In technical processes, high-energy radiation treatment is applied to increase the solubility and to alleviate the hydrolysis of the constituent cellulose of plant-based raw materials. The G-values of the main radiolysis products, as reported by Ershov,... 

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