Determination of protein content of whey powder using electrical conductivity measurement

A new method was developed to determine the protein content of commercial whey powder using electrical conductivity (EC) measurement. This method is based on a multi-point measurement technique and a mathematical model that can identify the contributions of protein and non-protein constituents to EC. Twenty-four samples were analysed separately by the Kjeldahl and EC methods under different conditions. A significant correlation (r = 0.96) was observed and no significant difference was found between these two methods (P < 0.05). The results demonstrate that the protein content of whey powder can be estimated by measuring changes in the conductivity of its dilute solution. (C) 1998 Elsevier Science Ltd. All rights reserved.