To classify the vegetable oils according to the six botanical
origins, an LDA model was constructed. With this model, an excellent
resolution between all category pairs was obtained (Fig. 2,
kw = 0.18). The variables selected by the SPSS stepwise algorithm,
and its corresponding model standardised coefficients, are given
in Table 2. According to this table, the main n-alkane ratios
selected by the algorithm employed in the LDA model construction
corresponded to C21/C25 and C24/C30. All the points of the training
set were correctly classified by leave-one-out validation. The
evaluation set, containing the 72 original data points, was used
to check the prediction capability of the model. Using a 95% probability,
all the objects were correctly classified; thus, the prediction
capability was 100%.