shows the scores plot for PC2 against PC3 which accounts
for 11.0% of total variance. It may be noted that extracts without
ethanol have positive PC2 scores while those prepared in ethanol
and its mixtures have negative values. Extracts prepared in
ethanol, dichloromethane and a binary mixture of ethanol: ethyl
acetate is on the upper left side with negative PC2 and positive
PC3 scores. From the PC2 and PC3 loadings (Fig. 4) one can observe
that the samples in the more positive region of CP2 contain higher
relative abundances of caffeine (tr = 4.53 min) whereas those in
the negative part have greater relative abundances of EGC
(tr = 3.66 min). Those extracts that are negative on the PC2, but
more positive on PC3 have greater relative abundances of EGCG
(tr = 5.28 min) whereas negative on both PC2 and PC3 has greater
relative abundance of EC (tr = 5.02 min). From this figure, it can
be concluded that the ethanol: ethyl acetate mixture extracts
larger amounts of EGCG followed by dichloromethane and pure
ethanol, while EC and EGC can be extracted with the other
mixtures containing ethanol. To confirm these results mixture
models were developed for the three catechins EC, EGCG and EGC.