Table 2. Summary of parameters for assessment of the quality of OPLS-DA models.

	Extracts	R2Xcum a	R2Ycum a	Q2Ycum b	P c
GC-TOF-MS	MW d	0.417	0.993	0.843	0.001
	DM e	0.379	0.984	0.834	<0.001
UPLC-Q-TOF-MS	MW	0.606	1.000	0.737	0.090
	DM	0.466	1.000	0.734	0.022
Nanomate LTQ-MS	Lipid f	0.521	0.812	0.587	0.015

^aR²X_cum and R²Y_cum are the cumulative modeled variation in X and Y matrix, respectively.

^bQ²Y_cum is the cumulative predicted variation in Y matrix.

^c P is p value obtained from cross validation ANOVA of OPLS-DA.

^dMW, methanol/water (1∶1, v/v).

^eDM, dichloromethane/methanol (3∶1, v/v).

^fThe lipid extract for nanomate LTQ-MS analysis was prepared as mentioned in M&M section.