Fructose production

Glucose isomerase catalyzes the conversion of D-glucose to D-fructose and has also been used extensively on an industrial scale.1184 Some, but not all, enzymes of this family require Co specifically, while others can function with other divalent ions. Environmental and health issues limit the concentrations of Co in culture media during D-fructose production and other metal ions are being sought as substitutes. Although the active site structure remains unknown, EXAFS, optical and EPR spectroscopy has suggest a low-spin divalent Co ion, bound by N and O-donors only (no S-donors). 

Figure 1. Schematic process biochemistry of enzymatic fructose production from starch. Reprinted with permission from ref. 1. Copyright 1990 Elsevier.

Zittan, L., Enzymic hydrolysis of inulin an alternative way to fructose production, Starch/Starke, 33, 373-377, 1981. 

Very concentrated, aqueous solutions containing 95% or more of D-fructose on a dry basis can be converted into a powder of the same (dry basis) composition by adding seed crystals of D-fructose and kneading the mixture into a crystalline mass which, on being cooled, solidifies to a stable, dry, high-D-fructose product.61... 

The oft quoted example of the isothermal photosynthesis reaction is fructose production. Carbon dioxide and water are forced together, by solar power, catalysed by chlorophyll. Oxygen is released. That is. 

Non-enzymic aldose-ketose isomerisations that are acid catalysed appear to involve a 1,2-hydride shift. During acid-catalysed rearrangement of glucose to fructose, the label of [2- H]glucose substrate is retained in the [l- H]fructose product, distributed equally between the proR and proS positions." In the reverse sense retention of the label of tritiated fructose in the glucose and mannose products was not complete. Similar observations were made for the xylose-xylulose interconversion." With an appropriate sugar configuration (ribose), even the base-catalysed reaction proceeds partly with retention of label, presumably by the same mechanism as with trioses. 

Recall that the isomerization reaction of glucose and fructose involves an enediol intermediate (Figure 7.15). This transformation makes C-l of the fructose product available for phosphorylation. 

IC IC, Paques (The Netherlands) Mixed Bottom 10-30 m h Top 4-8 m h (circulation) 3-6 Gas produced Inuline and fructose production from chicory beet 22, 23, 45... 

Y Radiolysis of crystalline D-fructose. Products and their G values. Further (as yet not quantified) products are glyceraldehyde, 3-butanone-l,2-diol, 2- and 3-... 

Fructose production glucose isomerase microbial and used internally 8... 

To illustrate the efficiency of enzyme utilization with this microporous enzyme support, 30 g of support material was immobilized with 22,000 IGIU of purified enzyme. The resulting reactor had an expressed activity of 726 IGIU/g at 60 C. A 40% w/w solution of 99% pure dextrose containing 2 g/1 MgS04 7H20 and 1 g/1 of NaHC03 at pH 7.5 was converted to a 45% fructose product in 6.5 min and an equilibrium product of approximately 50% fructose in less than 12 min residence time. The flow rate required to obtain a 45% converted product was 6 ml/min. 

In vitro synthetic enzymatic pathways can be designed carefully to shift equilibrium intermediates to final products. The commercial process of fructose production from glucose comprises sequential reactions. The last step, an isoenergetic reaction, is the conversion of glucose to fructose via glucose isomerase, resulting in an equilibrium constant close to 45/55. To increase the fructose percentage in the final product, a novel in vitro process has been... 

D13. We wish to use the local equilibrium model to estimate reasonable flow rates for the separation of dextran and fructose using an SMB. The isotherms are linear and both q and c are in g L. The linear equilibrium constants are dextran, 0.23 and fructose, 0.69. The interparticle void fraction = 0.4 and the intraparticle void fraction = 0.0. The columns are 40.0 cm in diameter. We want a feed flow rate of 1.0 L/min. The feed has 50.0 of each component. The desorbent is water and the adsorbent is silica gel. The columns are each 60.0 cm long. The limped parameter mass transfer coefficients using fluid concentration differences as the driving force are 2.84 l/min for both dextran and fructose. Operation is isothermal. Use multiplier values (see notation in Figure 18-14i of M] = 0.97, M2 = 0.99, M3 = 1.01, and M4 = 1.03. Determine the flow rates of desorbent, dextran product, fructose product, and recycle rate and find the ratio D/F. 

Ricca E, Calabrb V, Curcio S, lorio G (2009a), Fructose production by chicory inu-lin enzymatic hydrolysis a kinetic study and reaction mechanism . Process Biochem., 44,466-470. 

Di Luccio M, Borges C P, Alves T L M, (2002), Economic analysis of ethanol and fructose production by selective fermentation coupled to pervaporation effect of membrane costs on process economics , Desalination, 147,161-166. 

Glucose isomerase from yeast and other microorganisms Glucose Fructose Fructose production to increase sweetness of drinks without adding carbohydrate. Preparation of fructose to add to paper to increase its plasticity. 

Seidman, M., New Technological Development in D-Fructose Production, in Developments in Food Carbohydrate-1, G. G. Birch, and R. S. Shallenberger (Eds.), pp. 19-42, Applied Science Publishers, London, 1977. 

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