Application of classification-tree models to characterize the mycobiota of grapes on the basis of origin

The CT algorithm selected the fungal taxa and respective frequencies to classify grapes according to its region of origin. The ten-fold cross-validation technique was used for model evaluation. The success rate of the model was quantified and expressed in the number of correctly classified samples overall and into region. Furthermore, model refinement was performed using attribute selection algorithms and class redefinition. A simple tree model was generated that classified grapes into three regional origins: Douro, South (Alentejo and Ribatejo classes together) and Vinhos Verdes, on the basis of the incidence of Aspergillus niger aggregate and Penicillium thomii in samples with an accuracy of 82%. The merits and demerits of these models are discussed.