Foam and interfacial properties of Tween 20–bovine serum albumin systems

The foam properties of Tween 20 and BSA systems in Tris–HCl buffer solution were investigated by nitrogen-blowing method on a Foamscan. The foamability of Tween 20/BSA systems is obviously better than that of individual BSA system. The foams stabilized by BSA drained slower than Tween 20 systems with or without BSA. The foam stability of Tween 20 systems is enhanced by an addition of BSA. The optimal ratio of Tween 20 to BSA is determined for the most stable foams. Surface dilational rheological results indicate surface elasticity dominates the adsorbed layer and it is increased in the presence of BSA. The variation of surface elasticity accords with that of foam stability with an increase of Tween 20 concentration. It can be concluded surface elasticity dominates the corresponding foam stability.