Stability of oat avenanthramides

The three main oat avenanthramides, N-(4 ' -Hydroxy)-(E)-cinnamoyl-5-hydrox yanthranilic acid (Bp), N-(4 ' -hydroxy-3 ' -methoxy)-(E)-cinnamoyl-5-hydro xyanthranilic acid (Bf), and N-(3 ' ,4 ' -dihydroxy)-(E)-cinnamoyl-5-hydrox yanthranilic acid (Bc), and their corresponding cinnamic acids, p-coumaric (P), ferulic (F), and caffeic (C), were investigated for stability to pH, t emperature, and UV-light treatment. The retention of the avenanthramides af ter processing of oat-based food products was also analyzed. The avenanthra mide Be and the cinnamic acid C were sensitive to alkali and neutral condit ions, especially in combination with heat treatment, whereas the other comp ounds studied were more stable. The cinnamic acids but not the avenanthrami des were isomerized when irradiated with UV-light. The avenanthramides were restored after processing of oat-based products.