Acids sugars

Three kinds of sugar acids can be obtained from the common aldo carbohydrates. The first occurs from the oxidation of the aldehyde group to give an onic acid. 

D-glucuronic acid D-glucaric acid galactaric acid 

Mannitol is widely distributed in nature and occurs in the exudates of many plants. It has about half the sweetness of sucrose. Clinically, mannitol is administered intravenously as an osmotic diuretic in patients with acute renal failure. It is not metabolized appreciably, is filtered by the glomerulus, and is not reabsorbed by the tubules hence, it is excreted in urine (Chapter 39). The nonreabsorbable solute holds water, limits back-diffusion, and thus maintains urine volume in the presence of decreased glomerular function. Intravenous mannitol is also used to relieve an increase in pressure and in volume of cerebrospinal fluid. 

Xylitol, a five-carbon polyol, is widely distributed in the plant kingdom. It has about twice the sweetness of sucrose. 

A biosynthetic derivative of D lucuronate in plants and in animals other than primates and guinea pigs. Thus, for humans, it is a vitamin and is required in the synthesis of collagen. 

Ascorbic acid (L-xyloascorbic acid, vitamin C) is widely distributed in plant material, and the problem of its biosynthesis has been of great in- 

Alternative forms of writing D-glucurono-7-lactone to show inversion of configuration 

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Commonly, a juice drink contains 10% fruit juice, which usually is a blend of several fruits. The 1990 Federal Nutrition and Labeling Act requites declaration of juice content so that the consumer can make a more informed choice (3). With cocktails and juice drinks, added sugars, acids, flavorings, colorings, and nutrients can be used to provide a wide variety of stable products of uniform quaUty. Because drinks requite less juice than 100% juice products, the drinks can be sold at a lower price. 

Oxidation to Sugar Acids and Lactones. When the aldehyde group of an aldose is oxidized, the resulting compound is an aldonic acid (salt form = aldonate) (11)4. Some aldonic acids are products of carbohydrate metaboHsm. 

Another group of chelants that form stable chelates at high pH because of metal—alkoxide coordination are the sugar acids, such as gluconic acid [526-95-4] (1 )- Utility for this group is found in high alkalinity botde washes and other cleansers (19). 

Phosphorus tribromide and bromine 191 Phosphorylated deoxy sugar acids. . 88... 

After extraction, an extract purification stage is generally reconunended. This is most often done by liquid-solid exchange using resins such as Sephadex, Amber-lite XAD-7, or Cjg mini-columns. ° All the polar compounds are first trapped on the resin, and then in succession the sugars, acids, and other polar compounds (excluding polyphenolic compounds), polyphenolic compounds (excluding anthocyanidins), and anthocyanidins are respectively eluted with acidified water (HCl 0.01% v/v), ethyl acetate, and acidified methanol (HCl 0.01% v/v). 

Commonly, the application of rheological data from aqueous pectin solutions is limited to a narrow field in the food industry. The direct transfer to other properties is limited, since the rheological behaviour of pectins show very complex dependencies on other additives like sugars, acids, salts, and many more. 

Oxidation of Aldonic Acids. Preferential oxidation of the secondary alcoholic group adjacent to the carboxyl group in sugar acids or aldonic acids such as L-gulonic acid (XXV) can be carried out with chromic acid12 or with chlorates in the presence of a vanadium catalyst.13... 

Coordination Numbers of Ca2+ in a Selection of its Complexes with Carbohydrates and with Sugar Acids... 

Pectin.—This general term has been retained to designate pectinic acids which will form the customary pectin-sugar-acid gels. 

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