Materials and methods
The samples of virgin coconut oil (VCO), sunflower oil (SFO),
and corn oil (CO) were purchased from the local market in
Jogjakarta, Indonesia. The used plant oils were coming from the
mixture of three different brands with similar fatty acid (FA)
composition. The FA profiles of these oils are in accordance with
those listed in Codex Alimentarius (2003). Some factors contributed
to the slight FTIR spectral variation of VCO, such as origin of
plants, year of coconut plantation, maturity, etc. For this reason,
the samples of VCO were mixed to compensate this variation.