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

Table 4

The optimization wavenumber region of multivariate calibration for authentication of horse’s milk (HM) from cow’s milk (CM).

Wavenumber (cm^-1)	Multivariate calibration	Spectra	Calibration		Prediction
			RMSEC		RMSEP
1500-900	PLS	Normal	0.0345	0.9928	0.0315	0.9943
		1^st derivative	0.0476	0.9861	0.0500	0.9856
		2^nd derivative	0.0177	0.9981	0.0838	0.9571
	PCR	Normal	0.0415	0.9895	0.0349	0.9928
		1^st derivative	0.0543	0.9819	0.0522	0.9851
		2^nd derivative	09.1180	0.9121	0.1280	0.9021
3800-3000 and 1500-1000	PLS	Normal	0.0164	0.9984	0.0336	0.9931
		1^st derivative	0.0079	0.9996	0.0743	0.9733
		2^nd derivative	0.2760	0.2697	0.2960	0.0097
	PCR	Normal	0.0658	0.9733	0.0614	0.9776
		1^st derivative	0.0921	0.9471	0.1020	0.9587
		2^nd derivative	0.2470	0.5108	0.2670	0.3692
3800-3000 and 2000-700	PLS	Normal	0.0447	0.9878	0.0466	0.9867
		1^st derivative	0.0474	0.9863	0.0639	0.9793
		2^nd derivative	0.0436	0.9884	0.1180	0.9264
	PCR	Normal	0.0618	0.9765	0.0583	0.9793
		1^st derivative	0.0805	0.9597	0.0759	0.9723
		2^nd derivative	0.1710	0.8026	0.1960	0.7894
3800-3000 and 2100-700	PLS	Normal	0.0442	0.9881	0.0455	0.9874
		1^st derivative	0.0466	0.9867	0.0659	0.9779
		2^nd derivative	0.0428	0.9888	0.1210	0.9231
	PCR	Normal	0.0633	0.9753	0.0598	0.9785
		1^st derivative	0.0816	0.9587	0.0773	0.9720
		2^nd derivative	0.1740	0.7936	0.2010	0.7689
3400-3000 and 1500-700	PLS	Normal	0.0652	0.9739	0.0592	0.9787
		1^st derivative	0.0299	0.9948	0.0550	0.9867
		2^nd derivative	0.0329	0.9934	0.1630	0.8353
	PCR	Normal	0.0678	0.9717	0.0621	0.9765
		1^st derivative	0.0599	0.9779	0.0753	0.9725
		2^nd derivative	0.2530	0.4696	0.2720	0.3229
3600-3000 and 2000-900	PLS	Normal	0.0347	0.9926	0.0421	0.9894
		1^st derivative	0.0079	0.9996	0.0570	0.9834
		2^nd derivative	0.0430	0.9887	0.1010	0.9451
	PCR	Normal	0.0558	0.9809	0.0541	0.9824
		1st derivative	0.0765	0.9638	0.0729	0.9728
		2^nd derivative	0.1220	0.9044	0.1530	0.8852

The selection condition was assigned with bold.