ON EVALUATING THE EMULSIFYING PROPERTIES OF PROTEIN USING CONDUCTIVITY MEASUREMENTS

Selected oil-in-water emulsifying properties of alpha-lactalbumin, beta-lactoglobulin and bovine serum albumin were evaluated at solution concentrations ranging from 0.1 to 20 mg/ml. Changes in emulsion conductivity were recorded during and shortly after homogenization, and interpreted for each protein in terms of properties related to emulsifying activity and emulsion stability. A new quantitative analysis of the pattern of the entire conductivity curve is described and defended as an improvement on current interpretation of emulsion conductivity data which considers only the initial slope in evaluation of short term emulsion stability. In a manner consistent with past research, emulsion stability so calculated was found to increase with increasing concentration. Moreover, differences in emulsion stability among the three proteins were found to be consistent with known molecular influences on their surface activity at apolar interfaces.