Fig. 3

The PCA model of the eight fava bean varieties based on the UV spectra of the training set (nā=ā32 samples) (a). This model was challenged by 10 non-fava bean samples from Vicia sativa (VS) and Vicia monantha (VM) and all of them clustered away from the training set samples (blue dots, nā=ā32) and appear as outliers (green dots, nā=ā10) in (b). This model was also challenged by a validation set (nā=ā25, the green dot) representing the eight fava bean varieties and all of them clustered correctly with their respective cluster (c).