Table 4.

PLSR models developed with the benchtop and handheld spectrometers for whey protein powder samples containing the lowest concentration of adulterants (0.5%) using a spectral range of 950–1650 nm.

Instrument	Predicted Adulterant	R2	RMSEC (g/100 g)	R2CV	RMSECV (g/100 g)	R2Pred	RMSEP (g/100 g)
Metri benchtop	Urea	0.95	0.28	0.94	0.30	0.96	0.04
	Glycine	0.92	0.90	0.91	0.93	0.84	0.20
	Taurine	0.96	1.08	0.95	1.19	0.89	0.27
	Melamine	0.95	0.20	0.94	0.21	0.22	0.14
Nirscan nano with glass surface cuvette	Urea	0.93	0.32	0.89	0.43	0.57	0.13
	Glycine	0.84	1.22	0.75	1.56	0.42	0.37
	Taurine	0.87	1.86	0.84	2.08	0.56	0.55
	Melamine	0.89	0.29	0.84	0.34	0.24	0.12
Nirscan nano with plastic bag	Urea	0.95	0.27	0.93	0.33	0.22	0.13
	Glycine	0.88	1.07	0.77	1.51	0.34	0.42
	Taurine	0.89	1.69	0.83	2.11	0.51	0.60
	Melamine	0.90	0.27	0.86	0.33	−0.04	0.15