but not in brown rice powder, FRAP, ABTS and ORAC values rise and fall in parallel with the corresponding coryzanol
content. Furthermore, while the high ORAC values in Zeta-15 and FONAIAP-1 bran are consistent with the presence of
a-tocopherol and a-tocotrienol in these varieties, they also have paradoxically lower c-tocopherol and d-tocotrienol levels. It is interesting that the trends in association between antioxidant levels and antioxidant capacity in brown rice powder are different from those observed in the bran.
In order to analyze further the complex relationship between the levels of endogenous antioxidants and antioxidant
capacity, bran data (Table 1) were subjected to principal components analysis and multiple linear regression.
Principal components analysis organizes the data into groups that vary independently from each other.
Each group is composed of predictor variables that are statistically related to each other. The predictor variables yielded
three principal components or groups that accounted for 96% of the total variability (Table 3). Table 3 shows, for example, that polyphenols and c-oryzanol are colinear