Significance of phenol-protein interactions in modifying the antioxidant capacity of peas

The aim of this study is to evaluate the contribution of phenol-protein interaction (PPI) and its binding activity in strengthening the antioxidant capacity of peas after immersion with five phenolics under different heating conditions. The results showed that hydroxycinnamic acids (ferulic acid, coumaric acid, or caffeic acid) are better than hydroxybenzoic acid (gallic acid) in increasing superoxide dismutase (SOD) heat stability. In addition, the higher the temperature, the more evident was the enhancement. DPPH scavenging capacity and reducing power showed the same tendency. Further kinetic analysis proved that SOD with the best heat stability showed the largest activation energy during heating. Moreover, the contribution of phenol-protein binding to the antioxidant capacity was further estimated through complex purification and calculation of binding capacity. Coumaric acid was the most efficient phenolic compound in increasing antioxidant capacity and showed the highest binding capacity with pea protein. These results indicated that phenolic compounds might enhance the antioxidant capacity of peas during heating through phenol-protein interaction.