Foaming properties and air-water interfacial behavior of corn protein hydrolyzate-tannic acid complexes

The complexation of corn protein hydrolyzate (CPH) with tannic acid (TA) was utilized to improve the foaming properties of CPH itself, and the air-water interfacial behavior of CPH-TA complex was also investigated. The results showed that the surface hydrophobicity of pure CPH was significantly decreased in bulk solution after the complexation with TA. Compared with pure CPH, the foams stabilized by CPH-TA complex showed higher interfacial thickness between the bubbles, which well explained the better long term stability of the corresponding foams. Therefore, the complexation maintained the good foaming capacity of CPH itself, but considerably increased its foam stability. Moreover, the air-water interfacial behavior study demonstrated that the complexation slightly decreased the interfacial activity of CPH itself, but considerably increased its interfacial viscoelasticity, suggesting more stable of the air-water interface stabilized by CPH-TA complex compared with that stabilized by CPH alone. These findings indicated that foaming properties of the surface active components were closely related with its air-water interfacial behavior. The study suggested that CPH-TA complex could be used as a stabilizer in constructing the peptides-based foams.