2.5. Oil uptake during frying
After removing the adhered surface oil, the only remaining oil in
the potato cylinders was the oil that had been absorbed during frying.
This oil was determined using a Bchi Extraction system B-811
with 200 mL of petroleum ether as the extraction medium (boiling
range 40–60 C). The samples were ground and subjected to the
extraction (3 h) in pairs to obtain a more significant amount of
oil, and thus decrease the relative errors