Sucrose Fructose

In another fermentation process, Mosheky et al.18 reacted Saccharomyces cerevisiae with sugars and followed the progress of the fermentation with MIR-ATR. Two PLS models were used one for sucrose, fructose, and glucose and one for the ethanol. The authors did not specify SEPs for the experiment, but showed correlation coefficients of better than 0.998 for all analytes. 

In sucrose, fructose is present as the P anomer. Now, one of these sugars has acted as an alcohol to make a bond to the other sugar. We can look at this in two ways. Either frnctose acts as an alcohol to react with the hemiacetal glucose to form an acetal, or alternatively, glucose is the alcohol that reacts with the hemiketal fructose to form a ketal. In sucrose, the pyranose ring is an acetal, whilst the fnranose ring is a ketal. This all seems rather... 

If a very low molar concentration of enzyme is present, and a large excess of nonradioactive fructose is added, the enzyme will catalyze no net reaction but will change back and forth repeatedly between the free enzyme and glucosyl enzyme. Each time, in the reverse reaction, it will make use primarily of unlabeled fructose. The net effect will be catalysis of a sucrose-fructose exchange ... 

For example, the natural sugars (sucrose, fructose, etc.) arc best known for their contribution of sweetness to food products. The sugars, however, also perform other useful functions, including their natural preservative qualities and, in many foods such as baked goods, contribute considerable bulk to the finished product. As described under Sweeteners, a number of artificial, non-carbohydrate compounds serve as excellent sweeteners, but they lack the ability to achieve the desired bulk,... 

Invert sugar. Invert sugar, sometimes referred to as partially inverted refiner s syrup, is produced by acid or enzymic hydrolysis of the disaccharide sucrose into its 2004 component pails of fructose and dextrose (glucose). Invert syrups usually contain a mixture of sucrose, fructose and dextrose. The main advantage of such a syrup is the reduced likelihood of crystallisation and an increase in osmolality, which may be useful in reducing spoilage risk. 

Glucose, Sucrose, Fructose Pseudomonas fluorescens, Bacillus subtilus, Brevibacterium lactofermentum 71, 72,73... 

Figure 13.18 shows the effect of sorbitol. Agradual decrease in the CP with an increase in sorbitol concentration was observed. Some other polyhydric alcohols (including saccharides, viz. mannitol, glucose, sucrose, fructose, etc.) induced a similar decrease. A decrease in CP with saccharides has been observed for polyethylene glycol (PEG) and for sorbitol on polysorbate, a nonionic surfactant (Zatz and Lue, 1987 Attwood et al., 1989). Sjoberg et al. (1989) showed that all saccharides decrease the CP of PEG, which is well described by mean Leld theory. Also, an explanation was given for the difference between the saccharides in their ability to decrease the CP in aqueous PEG solutions. 

Depending on the process (acid- or base-catalyzed, leading to aromatic or color caramel) and on the particular sugar substrate (sucrose, fructose), different proportions and types of these molecules can be found.291 Some of the caramel components are similar to those observed when fructose and sucrose react in hydrogen fluoride, notably bisglycosylated difructose dianhydrides.287 341... 

For example. Figure 7.2 shows the glass transition temperature versus water activity relationship for lactose, sucrose and mixtures of sucrose-fructose and sucrose-Amioca, demonstrating that Tg decreases with increasing water activity (Roos and Karel 199Id). 

The sugars sucrose, fructose and glucose have also been found to affect bubble coalescence. On addition to water these sugars raise the surface tension and are desorbed from the air-water interface. Thus their effect on bubble coalescence equally cannot be described in terms of surfactant-like behaviour and certainly no charge effects are involved. Hence, even if an "explanation" could be found within the confines of the primitive model of electrolytes, that explanation could not accommodate this observation. The reduction in bubble coalescence achieved with increasing concentration is shown in Fig. 3.7. 

Changes in wheat carbohydrate chemistry due to chemical enzymatic degradation were measured on a macro scale by internal reflection (attenuated total reflection ATR) FT-IR spectroscopy from a spot size of 250 X 250 gm [51]. In this study, the absorption bands of sucrose, fructose, glucose, arabinose and galactose were identified, and spectra included for mahogany, huckleberry and oak, as well as for cellulose and cellophane. Both, principal component analysis (PCA) and plotting of PCI versus PC2 enabled distinctions to be made between filter paper, cello-... 

Dietary sources of fructose include fruit, honey, and the disaccharide sucrose. Fructose, a significant source of carbohydrate in the human diet (second only... 

Fructose is found in many plants and is an important portion of dietary carbohydrate. Most commonly it is ingested as free fructose or sucrose. Fructose is not actively transported by the intestinal mucosa, and variable proportions are converted to glucose in the process of absorption in man, about one-sixth is converted (Ml). Most of the metabolism of fructose occurs in the liver. If a renal threshold for fructose exists, it is very low. 

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