Sorbitol fructose

Fructose Sorbitol in the Lens Are Associated With Diabetic Cataract... 

Fig. 1. Solubility of some sugars, where ( —) represents fructose (- -), sorbitol (-----------), xylitol ( )> sucrose (- -), glucose (- -), lactose.

The most commonly used sweeteners are sucrose, glucose, fructose, sorbitol, and glycerin. Using sucrose (sugar) as a standard, with 100 units of sweetness. Table 6 lists the relative intensities of other sweeteners. Sweetness intensity changes with concentration. It has been estimated that the sweetness of glucose relative to cane sugar is 53 at a concentration of 8% but... 

Metabolic pathway for sorbitol and fructose. Sorbitol dehydrogenase is sometimes known as iditol dehydrogenase. Aldolase B is also called fructose-1-phosphate aldolase, in contrast to fructose-1,6-bisphosphate aldolase. 

Sample °Brix Sucrose Glucose Fructose Sorbitol... 

On the other hand, glucose is formed very rapidly from fructose, sorbitol and xlitol in the perfused rat liver. During a three hour perfusion, 60-707o of added xylitol and 45-507o of fructose or sorbitol are converted to glucose. When fructose or sor-... 

Fig. 4. Influence of fructose, sorbitol, xylitol and glucose on the lactate/pyruvate quotient during rat liver perfusion, x + S.D.

Fig. 5. Blood glucose concentration (2nd hour) and liver glycogen concentration following 2 h intravenous infusion of glucose, fructose, sorbitol and xylitol (0.3 gm/h) in rats.

Glycogen formation in diabetic animals is observed only when fructose, sorbitol or xylitol is administered (Fig, 6), No glycogen is stored in the liver following glucose infusion. This was shown by Bassler and his co-workers (1963) in alloxan diabetic animals and we have confirmed these results using streptozotocin diabetic animals (Fdrster et l., 1972). 

Fig. 7. Lactate/pyruvate quotient and lactate concentration in fasting voluntary subjects following intravenous infusion of glucose, fructose, sorbitol or xylitol (1.5 gm per kg BW).

This is one of the so-called "adverse effects" drawn attention to by Schumer (1971) and by Edwards ad Thomas (1972). We observed this effect some years ago with fructose (FOrster et al. 1967) and have also demonstrated similar findings with sorbitol and xylitol (FSrster et al,> 1970). We have also found increases in uric acid levels after oral administration of fructose, sorbitol, xylitol as well as sucrose (Fdrster et al.> 1971). Omission of sucrose from the diet for a week caused a decrease in the concentration of uric acid. On the other hand, a daily oral intake of 200 gm sucrose, 100 gm fructose, or 100 gm xylitol effected an increase in serum uric acid concentration (FOrster et al, 1972). 

In contrast to other authors, we have been unable to find severe adverse reactions by these substances. The rise in lactate concentration and the increase in the lactate/pyruvate ratio are common metabolic consequences of carbohydrate metabolism. The increase in uric acid and serum bilirubin concentrations has been reported as adverse reactions. However, the increase in uric acid concentration was also observed after oral sucrose intake. Rapid intravenous infusions of fructose, sorbitol and xylitol at high dosages of 1.5 g per kg were followed by an increase in the serum bilirubin concentration. Glucose, however, caused the same... 

Hie sugar substitutes (fructose, sorbitol, xylitol) are broken down to trioses without involvement of insulin, but the breakdown products are utilized in the liver for the synthesis of glucose, lactic acid and to some extent lipids. Glucose, the main product of this resynthesis, can only be utilized with the aid of insulin. The proportions of glucose and lactic acid formed vary from case to case and the arhounts produced cannot be foreseen... 

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