## 3 Results
The red number represents the peak number so that it can be identified in Table 2.  
Delphinidin-3-O-glucoside (peak 3, Figure 3) was the main component (40.64%) in GSE with the respective parent and daughter ion pairs (\(m/z\) 469/303), and Cyanidin-3-glucoside (peak 1, Figure 4) was the main component (86.49%) in BE with the respective parent and daughter ion pairs (\(m/z\) 453/287). The other three major peaks (peak 4, 17.82%; peak 11, 9.71%; and peak 12, 6.01%) revealed the \(m/z\) values of 453/287, which were identified as cyanidin-3-glucose 535/287, and 807, 617, 601 which were identified as malvidin derivatives. As shown in Table 2, all molar masses are higher for almost all compounds, e.g., molar mass for cyanidin-3-glycos is 449, and the mass spectrum shows 453 and the corresponding 287 for cyanidin. This may be due to the presence of deuterium atoms. The MS/MS spectrum of the ion at \(m/z\), for example, shows ions at \(m/z\) 186 for grape skin extract and \(m/z\) 228 for blackberry extract. Substitution of a D for H leads to the fragment ion at \(m/z\) 186 corresponding to C\({}_{2}\)HDO loss, while the ion at \(m/z\) 228 could correspond to losses of H\({}_{2}\)O. Fragmentations were definitively confirmed by accurate mass measurements. In order to separate these extracts and describe the anthocyanins characteristics of different groups, a principal component analysis (PCA) was carried out on the basis of the 13 identified compounds. PCA was applied to the raw data in order to reduce the number of dimensions of the system. A total of four principal components with eigenvalues >1 was obtained, explaining 100% of the total variance for the _Othello_ grape skin extract. PC1 and PC2 possessed relatively high percentages of variance (57.17 and 19.53%, respectively). PC1 was mainly represented by delphinidin derivatives (D\({}_{1}\), D\({}_{2}\), and D\({}_{3}\)), M\({}_{3}\) and M\({}_{4}\) malvidin derivatives, and Cyanidin-3-glucose-ethyl-coumaroyl. PC2 consisted primarily of the M\({}_{1}\), C\({}_{4}\), M\({}_{5}\), and M\({}_{6}\) malvidin derivatives, the first two with negative PC2 values. Figure 6 show the distribution of samples along these two principal components as well as the component weights of anthocyanins. On these biplots we can visualise sample differences, positive or negative correlations between anthocyanins, and the relationships that may exist between some groups of extracts and specified anthocyanins. Thus, Figure 6 shows that PC1 allowed the clustering of extracts of S3, S4, and S2 because of their high relative concentrations in M\({}_{1}\), M\({}_{4}\), M\({}_{5}\), D\({}_{1}\), D\({}_{2}\), and D\({}_{3}\). On the opposite side of PC1, the S1 extract is located and could be related to the cyanidin derivatives. According to the Pearson analysis, the C\({}_{3}\)-D\({}_{2}\), C\({}_{3}\)-M\({}_{3}\), D\({}_{1}\)-D\({}_{3}\), D\({}_{1}\)-D\({}_{4}\), D\({}_{2}\)-M\({}_{3}\), D\({}_{3}\)-M\({}_{1}\), D\({}_{3}\)-M\({}_{4}\), and M\({}_{2}\)-M\({}_{3}\) variables groups were identified as strongly positive correlated, while the C\({}_{3}\)-D\({}_{1}\), C\({}_{3}\)-D\({}_{3}\), C\({}_{3}\)-M\({}_{1}\), D\({}_{1}\)-D\({}_{2}\), D\({}_{1}\)-M\({}_{3}\), D\({}_{2}\)-D\({}_{3}\), D\({}_{2}\)-M\({}_{4}\), D\({}_{3}\)-M\({}_{3}\), and M\({}_{3}\)-M\({}_{4}\) groups present strong negative correlation. Among the five different extracts, S3, S4, and S2 are associated with the majority of this correlations, indicating that these mixtures are the most appropriate for the _Othello_ grape seeds' anthocyanins extraction. These findings are in agreement with the results obtained in the investigation of the total polyphenols. The same principle was  
Figure 6: Distribution patterns of 13 variables and 5 different extracts belonging to the _Othello_ grape samples in the two-dimensional space of PC1 and PC2 (the abbreviations of variables are presented in Table 2).