Saccharose formation

When the Claviceps strain SD 58 was grown in a culture medium containing saccharose the slow formation of alkaloids containing polar groups was observed (15). These could not be extracted from the water phase in either alkaline or acid medium by the usual solvents. Finally, the principal alkaloid was isolated by ion exchange procedures and purified by subsequent chromatographic methods. The alkaloid was identified as elymoclavine-O-jS-D-fructofuranoside (12 ... 

Oxyacids, like citric or tartaric acids, and polyols, like saccharose are also used, mainly as masking agents, in qualitative analysis. The action of some specific reagents, like oc-a -bipyridyl for iron(II) and dimethylglyoxime for nickel(II), is also based on the formation of chelate complexes. In quantitative analysis the formation of chelates is frequently utilized (complexometric titrations). ... 

Guyot et al. (1998) studied the inhibitory activity of 5-caffeoylquinic acid, the main component of the chlorogenic acids (see Section 2.1.4) on the formation of alkylpyrazines in Maillard reactions with model systems valine or leucine and saccharose. Applying their results to green robustas, they concluded that the aroma quality increased when the chlorogenic-acids content decreased and when the sucrose content increased. 

With the bases, saccharose forms definite compounds called sucrales (im)mperly sac arates, a name belonging to the salts of saccharic acid). With Ca it forms five compounds Hydrate of calcium dissolves readily in solutions of sugar, with formation of a Ca compound, soluble in H,0,... 

Similar effects take place with the glassy solutions of carbohydrates which are also characterized by the presence of the hydrated forms. The formation of e tr has been found in the solutions of glucose, galactose, sorbose, rhamnose, maltose, and saccharose (52). For instance, in the case of 4-5M solutions of glucose the EPR spectrum of e tr is essentially a narrow line with AH 10 1 oe. in H20 and 5 = 1 oe. in D20 (see Figure 6). The parameters of the optical band of e tr in these solutions are given in Table IV. In the system under consideration G(e tr) = 1.5 ( 50% ). 

After 48 hours record gas formation in adonite and saccharose broths. Determine indol formation in tryptophane broth by adding drop by drop, to avoid mixing with the medium, about 1 cc. of a two per cent alcoholic solution of p-dimethyl amido-benzaldehyd, then a few drops of concentrated hydrochloric acid. The presence of indol is indicated by a red color which is soluble in chloroform. There may be some unconverted tryptophane still present which will give a distinctly blue color-which is insoluble in chloroform. A mixture of the two will be either blue or violet. If from such a mixture of colors the red of indol be extracted with chloroform, proof of the presence of indol will be complete. 

Water solubility of CMCs is variable, depending on their degree of substitution and polymerization. They owe their hydrophilic qualities to their highly hydric carbohydrate character. CMCs used in very sweet beverages are less viscous, probably due to the formation of hydrogen bonds between the sugar and the gum. CMC-saccharose interactions depend on the order in which the products are added if the sugar is dissolved in the water first, its hydrophilic character reduces the... 

The enzymatic synthesis of certain polysaccharides is often considered to be by a polyinsertion mechanism. An example of this is the formation of the dextran polyglucoside (see Chapter 31) from saccharose under the influence of dextran saccharase enzyme. Fructose is eliminated in this reaction. It is... 

The formation of dextran was first observed as a troublesome slimy product in sugar manufacturing. The enzyme dextran saccharase produced by bacteria only affects saccharose and liberates fructose with dextran formation. A primer of the kind used in the amylose synthesis is not required. In the formation reaction, a very stable complex SEPi, is formed from the enzyme EPn binding to the dextran polymer and the saccharose S. This then decomposes to form fructose F ... 

The enzymatic synthesis of certain polysaccharides is often considered to be by a polyinsertion mechanism. An example of this is the formation of the dextran polyglucoside (see Chapter 31) from saccharose under the influence of the dextran saccharase enzyme. Fructose is eliminated in this reaction. It is assumed that the polymer chain P formed in previous steps is absorbed onto the enzyme. The substrate S (in this case, saccharose) is also absorbed onto the enzyme. A substrate-enzyme complex SEP is formed from the enzyme-polymer complex EP with the substrate S. This is then converted into an enzyme/polymer complex EP +i by insertion of the glucose residue of saccharose with liberation of fructose ... 

The third example corresponds to the case where sonochemistry is able to generate active species which catalyze the formation of the product(s). The catalyst may be an adventitious impurity sonochemically created as shown for the acid-catalyzed inversion of saccharose. Such an indirect, more or less hidden mechanism can be operative in the sonochemical addition of tin hydrides to olefins and alk5mes.i5 In this reaction, it was suggested that some radical species produced by solvent... 

The formation of 5-hydroxymethylfuran-2-carbaldehyde from saccharose proceeds via hydrolysis to fructofuranosyl cation and glucose (Figure 4.26). Ehmination of a proton and two molecules of water from the fructofuranosyl cation yields 5-hydroxymethylfuran-2-carbaldehyde. Under dry pyrolytic conditions and at temperatures above 250 °C, 90% of 5-hydroxymethylfuran-2-carbaldehyde originates from the fructose moiety and only 10% originates from glucose. Pentoses and L-ascorbic acid dehydrate in the same way as hexoses under addic conditions yielding furan-2-carbaldehyde (via reactive 3-deoxy-L-t/jreo-pentos-2-ulose and 3,4-dideoxypentosulos-3-ene) as the main product (see Section 5.14.6.1.5). 6-Deoxyhexoses, such as L-rhamnose, yield, analogously, 5-methylfuran-2-carbaldehyde (4-195). 

Figure 7.39 Saccharose-water state diagram t = temperature (°C), c = concentration, T , = equiiibrium formation-meiting of ice (equilibrium melting temperature of ice), 7, = equilibrium saturated solutlon-oversaturated solution, = glass transition temperature, = glass transition temperature of maximum concentrated liquid phase with saccharose content...

ACCUMULATION OF MVERSlON OF SACCHAROSE RESERVE FORMATION OF FATTY ACIDS MATERIALS... 

The rate of formation of osazones and their solubility, which differ substantially from case to case, can also serve as characteristic features useful in the identification of sugars. For example, osazones of glucose and fructose precipitate shortly after the heating of the solution, while saccharose requires 20 — 30 min of heating. Osazones of lactose and maltose precipitate only after cooling. In addition, phenylosazones of D-glucose, D-fructose, and D-mannose (which are identical) are insoluble in cold acetone, in contrast to phenylosazones of xylose, arabinose, rhamnose, and fructose. 

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