According to our results, the colour parameters of the model
systems were not significant influenced by food additives, except
iron sulphate and calcium sulphate. The reacted sample colour significantly
darkened when iron sulphate was added compared to
furan model systems with other food additives except iron sulphate.
The L⁄ and b⁄ values were significantly higher than any other
furan model system with food additives. Iron sulphate led to
significantly increased brown colour, and the incorporation of iron
sulphate in the Maillard reaction model significantly influenced
the brown colour. The L⁄ and b⁄ values were significantly lower
than any other furan model systems with other food additives
because adding calcium sulphate led to unclear sample colour in
various furan model systems. Fig. 1 shows the correlation between
colour parameters (L⁄, b⁄) and furan concentrations of various furan
model systems. A linear curve was obtained (R2 = 0.1341,
R2 = 0.0132) for the correlation. Only a slight relationship was
observed between colour parameters (L⁄, b⁄) and furan concentration
in the furan model systems. Therefore, it was difficult to
evaluate furan concentration using colour parameters.