Mechanism ofMaillard reaction
Back in the 1950s, when incidents of froth fermentation
were reported, it was recognised that the change was chemical
and not biological as there was an absence of yeast,
mould, bacteria or other micro-organisms. It was a spontaneous
exothermic chemical change with evolution of carbon dioxide
and the formation of volatile acids, mainly acetic. The
decomposition is essentially a reaction between amino acids
and reducing sugars (Maillard, 1912a, 1912b).
Honig (1965) summarised the mechanism of the Maillard
reaction as follows:
1. Amino acid + hexose amino acid-hexose compound (colourless)
2. Amino acid +amino acid - hexose compound polymerised
product (I) with dehydration (yellow)
3. Polymerised product (I) undergoes decarboxylation and
internal combustion
C02 + dehydration product (II) (brown melanoidin)
4. Polymerisation product (II) humic acid + insoluble nonsugars
(dark reddish- brown).