1 chemical properties
1.1 reactions
1.1.1 fructose , fermentation
1.1.2 fructose , maillard reaction
1.1.3 dehydration
chemical properties
figure 1: relationship between acyclic , cyclic (hemiketal) isomers of fructose
d- , l-isomers of fructose (open-chain form)
fructose 6-carbon polyhydroxyketone. crystalline fructose adopts cyclic six-membered structure owing stability of hemiketal , internal hydrogen-bonding. form formally called d-fructopyranose. in solution, fructose exists equilibrium mixture of 70% fructopyranose , 22% fructofuranose, small amounts of 3 other forms, including acyclic structure.
reactions
fructose , fermentation
fructose may anaerobically fermented yeast or bacteria. yeast enzymes convert sugar (glucose, or fructose) ethanol , carbon dioxide. carbon dioxide released during fermentation remain dissolved in water, reach equilibrium carbonic acid, unless fermentation chamber left open air. dissolved carbon dioxide , carbonic acid produce carbonation in bottled fermented beverages.
fructose , maillard reaction
fructose undergoes maillard reaction, non-enzymatic browning, amino acids. because fructose exists greater extent in open-chain form glucose, initial stages of maillard reaction occur more rapidly glucose. therefore, fructose has potential contribute changes in food palatability, other nutritional effects, such excessive browning, volume , tenderness reduction during cake preparation, , formation of mutagenic compounds.
dehydration
fructose readily dehydrates give hydroxymethylfurfural ( hmf ).
this process, in future, may become part of low-cost, carbon-neutral system produce replacements petrol , diesel plants.
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