FTIR Spectroscopy Combined with Chemometric for Analysis of Sesame Oil Adulterated with Corn Oil

Figures & data

Figure 1 PCA score plot for classification of SeO and other oils. SeO = sesame oil; CO = corn oil; RBO = rice bran oil; GSO = grapeseed oil; PO = palm oil; PKO = pumpkin oil; EVOO = extra virgin olive oil; SO = soybean oil; SFO = sunflower oil; CaO = canola oil; WO = walnut oil; VCO = virgin coconut oil.

Figure 2 FTIR spectra of SeO and CO at frequency of mid infrared region (4000–500 cm⁻¹).

Table 1  The statistical parameters for quantification of CO in SeO using PLS model

		R ^2 ^a
Spectra treatments	Number of factors	Calibration	Prediction	RMSEC ^b	RMSEP ^c
Normal	3	0.995	0.996	0.957	0.926
First derivative	4	0.998	0.992	0.528	1.31
Second derivative	7	1.00	0.976	0.101	2.52
^a R ^2: coefficient of determination.
^bRMSEC: root mean standard error of calibration.
^cRMSEP: root mean standard error of prediction.

Figure 3 The validation model of PLS for the relationship between actual and predicted values of CO using first derivative spectra.

Figure 4 The Coomans plot for classification of SeO and that adulterated with CO.

Figure 5 The Coomans plot for discrimination of SeO and SeO adulterated with CO, RBO, and GSO.