Sugar temperature dependency

Diffusion-mediated release of root exudates is likely to be affected by root zone temperature due to temperature-dependent changes in the speed of diffusion processes and modifications of membrane permeability (259,260). This might explain the stimulation of root exudation in tomato and clover at high temperatures, reported by Rovira (261), and also the increase in exudation of. sugars and amino acids in maize, cucumber, and strawberry exposed to low-temperature treatments (5-10°C), which was mainly attributed to a disturbance in membrane permeability (259,262). A decrease of exudation rates at low temperatures may be predicted for exudation processes that depend on metabolic energy. This assumption is supported by the continuous decrease of phytosiderophore release in Fe-deficient barley by decreasing the temperature from 30 to 5°C (67). 

Tables have been published relating Baume, Brix and specific gravity. As density is temperature dependent it is necessary to either bring the syrup to a fixed temperature or, as is more common in practice, to use temperature correction factors or tables. The relationship between density and concentration is slightly different for invert sugar or glucose syrups. The Brix scale is sometimes applied to products that are not sucrose syrups, such as concentrated fruit juice. Recipes are certainly in use that state boil to x Brix . In practice these instructions mean that the material should give the same reading as a sugar syrup of that concentration. As often happens in confectionery these practices have been proved to work empirically.

Amino-2-deoxy aldoses. The behaviour of O-unprotected sugars is exemplified in D-gluco series after basic hydrolysis of the starting 2-benzamidoglycoside followed by buffering the medium with carbon dioxide and treatment with thiophosgene, an intermediate isothiocyanate was obtained.320 However, NMR revealed a temperature-dependent equilibrium of this isothiocyanate with a trans-fused OZT (Scheme 5). 

To date, D coefficients of carbohydrates established with the PFGSE approactf - " have been undertaken to (1) validate the theoretical self-diffusion coefficients calculated from MD trajectories, (2) demonstrate the complexation of lanthanide cations by sugars,(3) probe the geometry of a molecular capsule formed by electrostatic interactions between oppositely charged P-cyclodextrins, (4) study the influence of concentration and temperature dependence on the hydrodynamic properties of disaccharides, and (5) discriminate between extended and folded conformations of nucleotide-sugars. ... 

Van Deenen and colleagues have shown (Biochim. Biophys. Acta 406, 169, 1975) that the activity of a phospholipase against phosphatidylcholine liposomes has a sharp temperature maximum at the phase transition temperature. In addition, Linden et al. (Proc. Natl. Acad. Sci. US 70, 2271, 1973) showed a marked temperature dependence of sugar transport into E. Coli fatty acid auxotrophs at the temperature corresponding to the onset of phase separations of the lipids. 

The temperature dependence of the chemical shifts of the base and sugar resonances of poly(dA-dT) in 0.1 M phosphate buffer is plotted in Figure 3. There are upfield and downfield shifts associated with the noncooperative premelting transition between 5 and 55°C while only downfield shifts are observed for most of the base and sugar protons on raising the temperature above 65°C in the noncooperative postmelting transition temperature range. 

Figure 8. The temperature dependence (5° to 95°C) of the base and sugar H-1 proton chemical shifts of polv(A-U) in 0.1 M phosphate, ImM EDTA, 2HtO,...

Figure 13. The temperature dependence of the base and sugar proton resonances of poly(dA-dT) in 1M NaCl, lOmM cacodylate solution (O), and in IM (2HtC),-NCI, lOmM phosphate solution (0). (2H C).NCI was purchased from Merck and used without further purification.

Figure 29. The temperature dependence of the base and sugar H-l resonances for poly(dA-dT) (O) and the daunomycin poly(dA-dT) complex, Nuc/D = 5 (9) in 1M NaCI, lOmM cacodylate, imM EDTA, 2H,0 solution...

Figure 30. The temperature dependence of the daunomycin anthracycline Ring D aromatic protons (7.3 to 7.7 ppm), the anomeric sugar H-V proton (5.1 to 5.5 ppm), and the anomeric CH.,-5 proton (1.2 to 1.3 ppm) of the daunomycin poly-(dA-dT) complex, Nuc/D = 25, 9 and 5 in 1M NaCl, lOmM cacodvlate, ImM EDTA, 2HjO. The poly(dA-dT) concentration was fixed at 19.3mM in phosphates and the daunomycin concentration was varied to make the different Nuc/D ratio...

In a study on model systems prepared from single amino acid and glucose in molar ratio 2 1, approximating the composition of shell-free cocoa beans, Rohan and Stewart (52) reported that amino acid destruction from heating was temperature dependent and practically ceased after one hour. Sugar destruction contintued at a rate dependent on reaction temperature until the end of the experiment (Table IX). 

Fig. 11 Standard representation of the temperature dependence of viscosity of aqueous sugar solutions of different concentrations as well as their reference-invariant approximation using ip = -0.500 (solid curve). For key parameters a(x)...

Fig. 11 shows the reference-invariant representation of the temperature dependence of viscosity of aqueous sugar solutions of different concentration (x - mass portion of cane sugar). To obtain this correlation, p and (T - T0) had to be transformed by the transformation or key parameters a = 1/yo [K] and b [Pa s] as w = p/b and u = (T-T0)/a, whereby a and b are functions ofx, see auxiliary diagram in Fig. 11. The reference temperature is T0 = 20 °C.

This difference in the AG values is especially observable in the temperature-dependent, nuclear magnetic resonance spectrum of 5,6-bis(acetamido)-l,6-anhydro-5,6-dideoxy-j8-L-idopyranose. This sugar contains a flve-membered and a six-membered ring amide in... 

Fig. 2. —Temperature Dependence of Net Transport of D-Xylose into Rhodotorula glutinis (gracilis) [—O—] (Heller and Coworkers, 1974)212 and of D-Ribose into Pichia fermentans [— —] (Barnett, 1975).20 [Rate of transport = Iog(0 (gg of sugar/mg of dry weight of yeast/min).]...

Pectin gels are a special case involving hydrogen bonding, and they require closely controlled conditions of sugar concentration and pH for their formation. The rate of set and the ultimate gel-strength vary with the temperature, but gelation itself is not temperature-dependent. 

The PEP-fructophosphotransferase system does not exist in Spirillum itersoii, Pseudomonas aeruginosa,181,182 or several other genera of aerobic, oxidative bacteria.183 The transport system for D-glucose, D-fructose, and D-mannitol is energy- and temperature-dependent, obeys saturation kinetics, and is inducible.181,182 This indicates the presence of a carrier-mediated transport-system.184 D-Fructose is transported as the free sugar, and trapped intracellularly by phosphorylation, An inducible fructokinase (EC 2.7.1.4) converts transported D-fructose into D-fructose 6-phosphate.181... 

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