Authentication of Nigella sativa Seed Oil in Binary and Ternary Mixtures with Corn Oil and Soybean Oil Using FTIR Spectroscopy Coupled with Partial Least Square

Table 4

PLS performances at some frequency regions for the determination of NSO in binary mixtures with SO.

Frequencies region (cm^−1)	Spectra	Calibration		Validation
		𝑅^2	RMSEC (% v/v)	𝑅^2	RMSEP (% v/v)
4000–650	Normal	0.9918	2.11	0.9927	2.44
	Derivative 1	0.9992	0.73	0.9988	0.59
	Derivative 2	0.9995	0.67	0.9991	0.53
2977–3028,; 1666–1739,; 740–1446	Normal	0.9995	0.71	0.9991	0.58
	Derivative 1	0.9994	0.75	0.9984	0.66
	Derivative 2*	0.9995	0.66	0.9994	0.62
2985–3024,; 752–1755	Normal	0.9993	0.76	0.9992	0.66
	Derivative 1	0.9997	0.47	0.9988	0.63
	Derivative 2	0.9993	0.66	0.9994	0.57
752–1755	Normal	0.9992	0.90	0.9996	0.46
	Derivative 1	0.9993	0.74	0.9997	0.44
	Derivative 2	0.9996	0.59	0.9997	0.64

*The frequency region and FTIR spectral treatment selected for quantification were marked with italics.