Rancidity Estimation of Perilla Seed Oil by Using Near-Infrared Spectroscopy and Multivariate Analysis Techniques

Table 4

Results of PLSR calibration and validation for acid and peroxide values of perilla seed oil according to preprocessing methods.

Preprocessing methods	Acid value				Peroxide value
	Calibration		Validation		Calibration		Validation
	^2	RMSE	^2	RMSE	^2	RMSE	^2	RMSE
Raw data	0.8257	0.0913	0.6887	0.1220	0.8209	1.7061	0.8036	1.7869
MSC	0.8643	0.0806	0.7369	0.1122	0.8255	1.6842	0.7858	1.8660
SNV	0.8703	0.0787	0.7272	0.1142	0.8268	1.6781	0.7905	1.8455
Normalization
Max	0.8741	0.0776	0.7225	0.1152	0.8340	1.6428	0.7914	1.8416
Mean	0.8328	0.0894	0.6681	0.1260	0.8037	1.7863	0.7816	1.8844
Range	0.9163	0.0633	0.7413	0.1112	0.8460	1.5821	0.7829	1.8787