Experimental potato flour obtained from coloured-fleshed
tubers that had previously been blanching in a solution of SO2
had higher antioxidant activity than the raw material. The presence
of SO2, which is reductive, caused an increase in the reductive
power (FRAP) of the experimental flour and the activity was confirmed
by the ABTS and DPPH tests. The highest increase of FRAP
antioxidant activity was observed in flour from Herbie 26 potatoes
(15 times as much as raw material) and the lowest in flour from
Blue Congo potatoes (1–3 times higher). Experimental flour manufactured
from tubers of the purple-fleshed Salad Blue variety and
the red-fleshed Herbie 26 had much higher antioxidant activity
than the raw material and also had higher or similar activity compared
to the flour prepared from the remaining 2 potato varieties.