For the further fair comparison, three external independent test sets from the recent work of Dagan-Wiener et al. (2017) are used for the independent assessment and are given as follows: “Bitter New” dataset (23 bitterants), “UNIMI set” dataset (23 bitterants and 33 non-bitterants) and “Phytochemical Dictionary” dataset (49 bitterants and 26 non-bitterants). The prediction results by BitterPredict for these three test sets are reported in the work of Dagan-Wiener et al. (2017) and compiled in Tables 2–4 for the convenience of comparison. BitterX prediction is conducted by the manual uploading of each molecule to the web server one by one, which gives results in Tables 2–4. The prediction by e-Bitter is performed in batch for these three datasets and offers the results in Tables 2–4. In addition, scatter plot of MCC (test set) vs. F1-score (test set) or accuracy (test set) vs. F1-score (test set) for all the models are plotted in Figures 4–6.