2.2.1. Raw material and sample preparation
Potato tubers were kept at 5 ± 1 ◦C in darkness prior to
processing. First the potatoes were washed in water to eliminate
any surface contamination, then hand-peeled and cut
with a manual cutter into slices of about 3–4 mm. The potato
slices were immediately dipped into distilled water containing
ascorbic acid and citric acid in concentrations chosen
according to a central composite design (CCD). Levels of
0–5% (v/w) for ascorbic acid and 0–2.5% (v/w) for citric
acid were used. The ratio between the solids (sliced potatoes)
and the soaking solution was 1:3. During the immersion, the
solution was agitated for 2 min. After each assay, the potato
slices were gently dried for 1 min with a manual centrifugal
machine