Table 2.

PLS models of FA, UFA, OA, LA with different method.

Compound	Pretreatment method	R2cal	RMSEC	R2cv	RMSEP
FA	Original	0.867	0.0118	0.762	0.0162
	SNV	0.861	0.0121	0.762	0.0158
	MSC	0.906	0.0099	0.763	0.0156
	D1	0.913	0.0095	0.770	0.0156
	D2	0.853	0.0124	0.681	0.0184
	D1 + SNV	0.913	0.0096	0.780	0.0154
	D1 + MSC	0.906	0.0099	0.763	0.0155
UFA	Original	0.857	0.0095	0.735	0.0131
	SNV	0.833	0.0102	0.709	0.0135
	MSC	0.830	0.0103	0.735	0.0131
	D1	0.907	0.0076	0.737	0.0129
	D2	0.843	0.0099	0.626	0.0155
	D1 + SNV	0.892	0.0082	0.729	0.0134
	D1 + MSC	0.905	0.0077	0.724	0.0132
OA	Original	0.594	0.0138	0.328	0.0179
	SNV	0.570	0.0142	0.302	0.0182
	MSC	0.576	0.0141	0.355	0.0176
	D1	0.376	0.0172	0.249	0.0192
	D2	0.623	0.0133	0.207	0.0193
	D1 + SNV	0.517	0.0151	0.265	0.0188
	D1 + MSC	0.558	0.0144	0.353	0.0179
LA	Original	0.393	0.0122	0.226	0.0140
	SNV	0.378	0.0124	0.222	0.0136
	MSC	0.372	0.0125	0.226	0.0139
	D1	0.301	0.0131	0.169	0.0147
	D2	0.183	0.0142	0.130	0.0149
	D1 + SNV	0.406	0.0210	0.209	0.0140
	D1 + MSC	0.213	0.0139	0.129	0.0148

FA: Fatty acids.

UFA: Unsaturated fatty acids.

OA: Oleic acid.

LA: Linoleic acid.

PLS: Partial least squares.

SNV: Standard normal variate.

MSC: Multiplicative scatter correction.

D1: First derivative (Savitzky-Golay).

D2: Second derivative (Savitzky-Golay).

R²_cal: Coefficients of determination for calibration.

RMSEC: Root mean square error of calibration.

R²_cv: Coefficient of determination for cross-validation.

RMSEP: Root mean square error of prediction.