Abstract:
Complexation between bovine serum albumin (BSA) and citrus peel pectin (CPP) was studied by changing pHs and mass ratios with turbidity, dynamic light scattering, centrifugation and viscosity measurements. Interfacial behavior at specific pHs and mixing ratios were also carried out by individual measurements using bubble tensiometer and wilhelmy plate technique. We investigate comparative long term stability of foam in protein solution and in a mixed protein (BSA) - polysaccharide (CPP) system. The foam stability is improved for samples containing soluble complexes which are almost at pH around isoelectric point of BSA. Initial foam formation solely depends on free protein content in bulk, and soluble complexes slow down the drainage rate by their presence at air/water interface, which finally results in the stabilization of foam. Atomic force microscopic image analysis shows how this interaction between BSA and CPP leads to change in morphology with size and shape by forming complexes. These findings have significant value for application of protein- polysaccharide complex in foam stabilization which is useful in different engineering applications such as food, pharmaceutical industries, and cosmetics.