Glycosides sugars, table

The data in Table VIII are presented in the order of the conformational stability observed for methyl glycosidation (see Table I on p. 99 and Table II on p. 105). In each of the three cases where data for both anomers are available, the trans-1,2 anomer is the more stable, and a lower rate-constant is observed. This is the same pattern as that observed in Table II. However the order of conformational stability given earlier is not observed here. The arabinofuranosides show the maximum stability, and the D-galactofuranosides and L-fucofuranosides, having similar conformations, show a similar stability, However, the furanosides of D-lyxose, n-mannose, and i>rhamnose show an unexpectedly high stability which is almost as great as those of the furanosides of the first-mentioned sugars. These data lead to the conclusion that the conformational stability for transition complexes... 

The most familiar of all the carbohydrates is sucrose—common table sugar. Sucrose is a disacchar ide in which D-glucose and D-fructose are joined at then anomeric carbons by a glycosidic bond (Figure 25.7). Its chemical composition is the same ine-spective of its source sucrose from cane and sucrose from sugar beets are chemically identical. Because sucrose does not have a free anomeric hydroxyl group, it does not undergo mutarotation. 

Table X), sweetness is not normally observed for ethyl glycosides, and does not occur at all for sugars having larger aglycons these are either bitter or very bitter. ...

Methylation analyses of fractions N1 indicated that the linkage pattern of uronic acid residues (table 2) remains unchanged during ripening whereas the glycosidic linkage composition of neutral sugar residues showed different alterations. 

With the death of the bean, cellular structure is lost, allowing the mixing of water-soluble components that normally would not come into contact with each other. The complex chemistry that occurs during fermentation is not fully understood, but certain cocoa enzymes such as glycosidase, protease, and polyphenol oxidase are active. In general, proteins are hydrolyzed to smaller proteins and amino acids, complex glycosides are split, polyphenols are partially transformed, sugars are hydrolyzed, volatile acids are formed, and purine alkaloids diffuse into the bean shell. The chemical composition of both unfermented and fermented cocoa beans is compared in Table 1. 

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