Effect of solution conditions on protein damage in foam

In this study we investigated the conditions under which protein damage dur ing foaming could be reduced. We used bovine serum albumin (BSA), immunoglo bulin G (IgG), pepsin, catalase and lysozyme. The parameters examined were ionic strength, pH, protein concentration and the addition of sugars (treha lose and sucrose). Results showed that protein damage can be reduced by ope rating at optimal ionic strength and pH, and to a lesser extent, by the add ition of sugars. Solution conditions under which the native structure of th e protein was stabilised in solution favoured a reduction in the amount of damage, due to lower surface adsorption. The actual quantity of protein dam aged in foaming was found to be relatively insensitive to changes in the bu lk protein concentration, provided that the concentration was near to, or g reater than, the apparent CMC value. (C) 2000 Elsevier Science S.A. All rig hts reserved.