T. Haryati et al., DETERMINATION OF IODINE VALUE OF PALM OIL BY DIFFERENTIAL SCANNING CALORIMETRY, Journal of the American Oil Chemists' Society, 74(8), 1997, pp. 939-942
Iodine value (IV) is used as a parameter in process control as well as
a quality parameter in traded palm oil products. IV measures the numb
er of double bonds in the molecular structure of an oil. To form a dou
ble bond, carbon requires more energy (615 kj/mol) than to form a sing
le bond (350 kj/mol). Therefore, the thermal behavior of an oil could
reflect its iodine value. This study was conducted to demonstrate the
use of a differential scanning calorimeter (DSC) to determine the IV o
f palm oil and its products as an attempt to reduce the use of chemica
ls in the analysis. The DSC thermograms of palm oil showed a clear sep
aration of the substances that have low melting points (low-T), consis
ting oi triunsaturated, monosaturated and disaturated triglycerides, f
rom the high ones (high-T), consisting of trisaturated triglycerides.
Regression analysis showed that the peak characteristics, namely, area
and height of the low-T group and height of the high-T group in the h
eating thermogram and also the height of the high-T group in the cooli
ng thermogram, can predict the IV oi palm oil with R-2 higher than 0.9
9. This study concludes that DSC can be used to determine the IV of pa
lm oil and its products.