Focusing into the influence of the sugar addition during roasting
process, correlation results show a clear and significant (0.701,
p < 0.001) tendency to increase the DPPH antioxidant capacity with
the amount of sugar added during roasting process. Also T100L
coffee exhibited higher DPPH results than the commercial conventional
roasted coffees. A significant and good correlation between
DPPH and Absorbance at 420 nm, proposed as a good marker
of torrefacto roasting process, has been found (0.721, p < 0.001).
Moreover, DPPH quenching activity contributed partially to the PC2
in Principal Component Analysis (Fig. 2) that mapped those coffees
roasted with sugar addition (torrefacto) in the top half-part of the
graphic. These findings are in agreement with those obtained in
commercial torrefacto roasted coffee blends . The higher DPPH
quenching activity can be attributed mainly to the formation of
Maillard Reactions and caramelization antioxidant products
, but the influence of torrefacto roasting on phenolic compounds should be
deeper studied in those coffees roasted with increasing amounts of
sugar addition