Malaysia is the largest producer and exporter of palm oil
products. For trading purposes, iodine value (IV), free fatty acid (FFA),
peroxide value (PV) and anisidine value (An V) are some parameters
used to check the quality of palm oil. They are normally analyzed
based on the chemical methods. However, many of these standard
methods are time consuming. Therefore, simpler and faster methods,
such as IR spectroscopy are necessary.
In this study, Fourier transform infrared (FTIR) calibration
models have been developed to correlate the IV, FFA content, PV and
AnV in palm oil, that were obtained from the standard methods. In IV
determination, a calibration standard was prepared by blending palm
stearin and palm superolein. A validation approach yielded a good coefficient of determination (.R2). Subsequently, 42 palm oil samples
with IV ranging from 53 to 65 were also investigated using partial
least squares (PLS) and principle component regression (peR). The
results gave .R2 of 0.94443 to 0.98853. In the FFA determination, a
calibration set was prepared by spiking different amount of oleic acid
to a series of palm olein. The cross-validation procedure gave R2 of
0.997. In the fourth study, FTIR method to determine PV of palm
olein was studied. A wide calibration range of PV was prepared by
adding oxidized palm oil into the unoxidized palm olein. The SEP and
J?2 gave 0.172 and 0.996, respectively. In the final study, the FTIR
spectroscopy was described to predict An V of palm olein. The
calibration set was prepared by mixing the thermally oxidized palm
olein and the unoxidized palm olein. The precision of this method was
shown to he comparable to chemical method used for measurement
of AnV.
The results of this study showed that FTIR methods can be
used as alternative to measure a number of trading parameters m
palm oil to replace the tedious, time-consuming chemical method
