The freeze-dried potato samples and the defatted samples of
snacks were extracted by 70% aqueous acetone (0.1% acetic acid)
in a graduated tube. The mixture was homogenised using a vortex
for 30 s and allowed to stand for 2 h at room temperature. The acetone–
water solution was partitioned with chloroform to remove
the lipophilic compounds. Next, the acetone–water fraction was
collected and placed on a Büchi rotary evaporator until all residual
acetone was evaporated. The remaining aqueous extract was
brought to a known volume with distilled water and stored at
20 C until analysis. The samples were filtered with 0.2 lm filters
before HPLC-MS analysis.