Mango fruit (Mangifera indica L.) is highly
perishable and must therefore be quickly stabilized. Drying
appears to be one of the most promising stabilization
solutions. The traditional mango drying process can be
divided into two phases: the first, which is performed at
*80 C for 10 to 12 h, sees water activity (aw) decline
from 0.98 to 0.8. During the second phase, the drying
temperature is reduced to 50 C until aw reaches *0.6.
These conditions are highly favorable to enzymatic and
non-enzymatic reactions (1st and 2nd step, respectively).
The focus of this work was therefore to highlight the
effects resulting from the coupling of aw and temperature
on the development of these classes of reactions during the
whole process. Several precursors (reducing sugars and
amino acids) and intermediary products of the Maillard
reaction were analyzed to estimate non-enzymatic reaction
intensity when polyphenoloxidase (PPO) was associated
with enzymatic browning. We were able to show that the
highest production of 5-hydroxymethyl furfural (5-HMF)
as a Maillard reaction marker occurs mainly for an aw of
0.6. Kinetic analysis of Maillard reaction precursors and
intermediate products in model mango system helped us
identify asparagine and arginine as limiting precursors, and
5-HMF as a significant aw-dependent product. The impact
of the aw on the thermal degradation of PPO proved to be
radically different. After 8 h at 40 C, the PPO was almost
totally inhibited if this treatment is conducted on a sample
at aw 0.65, while residual activity was estimated to be
69.4 % for a sample at aw 0.98.
Keywords Mango Drying Water activity Maillard