Mechanistic investigation of the oxidative degradation of
D-fructose (D-Fruc) has been studied by spectrophotometric technique.
Molecular mechanics (MMþ) calculations suggest that the potential energy
(PE=kcal mol
1) of the D-fruc (opening structure) is at least three (3.71)
times more stable than the PE of the cycling structure of the same matrix.
The oxidation constant (Kox) of the anionic form of the D-Fruc (Fruc-NaOH)
is about seven times greater than that of the protonated form (Fruc-H2SO4).
Therefore, the anionic form is more highly oxidizable than is the cationic
form of this matrix. The limit of detection can be as low as 18ppm (mg
L
1) of D-Fruc. This is about 60 times lower than the blood sugar level
(BSL) or 100 times lower than that reported previously. The proposed procedure
was applied successfully for the oxidation of D-Fruc in uni-fructose
powder. The anionic form of D-Fruc (Fruc-NaOH) has the ability to store
energy about 744.72 kJ g
1 h at 608nm in a condensed lightweight form.
Kinetic parameters of the oxidative degradation of the anionic form of DFruc
at different concentration were deduced. A number of models were
used to evaluate the kinetic parameters. The mechanism of the degradation
of D-Fruc is explained on the basis of kinetic parameters.