Emulsifying properties of BSA in different vegetable oil emulsions using conductivity technique

The stability of oil in water emulsions using bovine serum albumin (BSA) as an emulsifying agent was investigated using the conductivity technique. The effect of oil volume fraction (0.25-0.56 v/v) and BSA concentration (0.05-5.00 mg/ml) was studied using four vegetable oils, namely corn, olive, soybean and sunflower. In general, it was found that the effect of increasing BSA concentration from 0.05 to 5.0 mg/mi on emulsion stability showed a systematic behavior characterized by a decrease followed by an increase and then by a decrease. Moreover, corn Oil showed no emulsification at low BSA concentration, and/or higher oil volume fraction (phi(o)). Unlike other oils, olive oil could be emulsified to higher phi(o). As far as phi(o) is concerned, emulsion stability showed an increase with increasing phi(o). Finally, emulsifier activity showed a weak dependence on BSA concentration, while increasing phi(o) positively affected the emulsifier activity. (C) 2000 Elsevier Science Ltd. All rights reserved.