heating (Fig. 3a). The moisture coming from the fried product
accelerates the hydrolysis of oil. It is known that water can
promote the hydrolysis of triacylglycerols to form a combination of mono and diacylglycerols, glycerol and free fatty acids.
The increase in FFA was due to the cleavage and oxidation of
double bonds to form carbonyl compounds, which oxidized
to low molecular weight fatty acid during frying (Irwandi and
Cheman, 2000; Ramadan et al., 2006). The increase in FFA level
is not a very reliable parameter for the degradation of frying oil,
because it is difficult to differentiate between the FFA formed
by oxidation or by hydrolysis (Ramadan et al., 2006). Moreover,
low molecular weight FFA may be lost through volatilization
during frying (Sulieman et al., 2006).