2.6. Surface area
The apple slices’ surface area was measured after scanning 4
slices of each apple (n ¼ 8) before and after several enrichment and
drying processes with an Epson Perfection 2400 Photo Scanner
(Long Beach, CA, USA). Afterward, the apple chips on the scanned
images were marked manually and the surface area was calculated
by the ImageJ 1.44a software using a defined length scale of
100 mm as reference.