Quantification of the adulteration concentration of palm kernel oil in virgin coconut oil using near-infrared hyperspectral imaging
Phiraiwan Jermwongruttanachai, Siwalak Pathaveerat, Sirinad Noypitak
Abstract
The adulteration concentration of palm kernel oil (PKO) in virgin coconut oil (VCO) was quantified using near-infrared (NIR) hyperspectral imaging. Nowadays, some VCO is adulterated with lower-priced PKO to reduce production costs, resulting in downgrading of the quality of the VCO. This research used NIR hyperspectral imaging in the wavelength region 900–1650 nm to create a quantitative model for the detection of PKO contaminants (0–100%) in VCO and to develop predictive mapping. The prediction equation for the adulteration of VCO with PKO was constructed using the partial least squares regression method. The best predictive model was pre-processed using the standard normal variate method with values of coefficient of determination of prediction of 0.991, root mean square error of prediction of 2.93%, and residual prediction deviation of 10.37. The results showed that the model could be applied for the quantification of the adulteration concentration of PKO in VCO. Prediction adulteration concentration mapping of VCO with PKO was created from a calibration model that showed the color level according to the adulteration concentration in the range 0–100%. NIR-hyperspectral imaging could be clearly applied to quantify the adulteration of VCO with color level map displaying and provided a quick, accurate, and non-destructive detection method.