The Application of FTIR Spectroscopy and Chemometrics for the Authentication Analysis of Horse Milk

Table 3

The optimization wavenumber region of multivariate calibration for authentication of horse’s milk in binary mixture with goat’s milk.

Wavenumber (cm^-1)	Multivariate calibration	Spectra	Calibration		Prediction
			RMSEC		RMSEP
1500-900	PLS	Normal	0.0252	0.9961	0.0284	0.9954
		1^st derivative	0.0293	0.9948	0.0381	0.9922
		2^nd derivative	0.0252	0.9961	0.0632	0.9763
	PCR	Normal	0.0300	0.9945	0.0284	0.9954
		1^st derivative	0.0358	0.9922	0.0459	0.9884
		2^nd derivative	0.0620	0.9763	0.0797	0.9618
1800-1000	PLS	Normal	0.0979	0.9399	0.1120	0.9251
		1^st derivative	0.0094	0.9995	0.0383	0.9930
		2^nd derivative	0.0087	0.9995	0.0739	0.9672
	PCR	Normal	0.0323	0.9937	0.0355	0.9941
		1^st derivative	0.0399	0.9903	0.0602	0.9809
		2^nd derivative	0.0709	0.9690	0.0888	0.9559
3500-2800	PLS	Normal	0.0705	0.9693	0.0796	0.9666
		1^st derivative	0.1040	0.9325	0.1420	0.8778
		2^nd derivative	0.1600	0.8296	0.2380	0.5642
	PCR	Normal	0.1100	0.9237	0.1070	0.9386
		1^st derivative	0.1930	0.7393	0.2140	0.6713
		2^nd derivative	0.2370	0.5607	0.2820	0.2386
3000-2800	PLS	Normal	0.0602	0.9777	0.0894	0.9527
		1^st derivative	0.0580	0.9793	0.0883	0.9529
		2^nd derivative	0.1130	0.9191	0.1440	0.8659
	PCR	Normal	0.0735	0.9666	0.0889	0.9525
		1^st derivative	0.0993	0.9381	0.1270	0.8987
		2^nd derivative	0.2100	0.6808	0.2340	0.5775
3200-2800 and 1300-1000	PLS	Normal	0.0474	0.9863	0.0500	0.9859
		1^st derivative	0.0248	0.9962	0.0417	0.9903
		2^ndderivative	0.0093	0.9995	0.0794	0.9612
	PCR	Normal	0.0592	0.9784	0.0643	0.9775
		1^st derivative	0.0471	0.9864	0.0554	0.9829
		2^nd derivative	0.1470	0.8596	0.1380	0.8971

The selection condition was assigned with bold.