Rapid Characterization of Tanshinone Extract Powder by Near Infrared Spectroscopy

Table 8

The best preprocessing methods for near infrared spectra of partial least squares models of physical attributes.

Index	Processing method	LVs	Calibration				Validation
				RMSEC	RMSECV	BIAScal		RMSEP	RPD	BIASpre
SSA/m^2·g^−1	S-G 1st	11	0.9591	0.021	0.045	0.017	0.8282	0.025	1.7	0.020
/m	S-G 1st	12	0.9867	0.74	2.4	0.56	0.9720	0.76	2.8	0.54
/m	S-G 1st	5	0.9392	6.0	7.1	4.6	0.9561	4.1	3.3	3.28
/m	S-T	11	0.9477	10	16	7.5	0.9058	8.7	2.5	6.3
/g·cm^−3	WDS	10	0.8830	0.034	0.038	0.027	0.8940	0.023	1.9	0.019
Moisture/%	S-G 1st	12	0.9679	0.26	0.68	0.18	0.9191	0.33	2.6	0.25

LVs means numbers of latent factors of the PLS model. and represent correlation coefficients for calibration and validation sets, respectively. RMSEC, RMSECV, and RMSEP represent the root mean square error of calibration, cross validation, and prediction, respectively. BIAS_cal and BIAS_pre represent bias for calibration and validation, respectively. RPD means relative predictive deviation.