As shown in Fig. 5a, phenol extracts from all oat samples (with or without a-amylase treatment) had capability to protect against protein oxidation, and that enzyme treatment enhanced that protection.Amylase treatment resulted in significant higher (p < 0.05)activity than heating-only treatment (control, CK) (Fig. 5b). The heating-only treatment showed no significant (p > 0.05) effect on the extent of protection against protein oxidation of oat samples over the time scale studied. While the extent of protection against protein oxidation of enzyme-treated samples showed an overall increase (except that after 30, 60 min treatment) with treating time(time; p < 0.05, heat/enzyme treatment time; p < 0.05). The increase of ability to protect against protein oxidation by amylase treatment was consistent with the increase of phenolic content, indicating that phenolic compounds might be the major factors that contributed to this activity. Phenolic compounds derived from malt extract were also able to protect proteins from oxidative damage (Yang et al., 2010). However, the decrease of activity to protect proteins from oxidative damage in heating-only samples was not consistent with the significant increase of total phenolic content and the content of CA, V, and avenanthramide 2f. This might be due to the extent of the increase of these compounds was not great enough to cause significant increase of protein oxidation inhibitory activity. Significant increase of the content of these three compounds and other tested components might be the important reason that resulted in the increase of protein oxidation inhibitory activity in oat pastes.