FOAMING PROPERTIES OF PROTEINS - EVALUATION OF A COLUMN AERATION APPARATUS USING OVALBUMIN

A specially designed small‐scale foaming apparatus was used to determine dynamic and static foaming properties of proteins. Foam was produced by sparging nitrogen at a known rate through a dilute protein solution. The temperature of the protein solution and protein foam was maintained by a water‐jacketed column. Ovalbumin was used as the reference protein. Foaming properties (foaming capacity, foam strength, and stability) were improved when the protein concentration was increased (0.01–0.1%); when sodium chloride was added to the protein solution and when the temperature was decreased from 40 to 2°C. Foaming properties were optimum at pH 3.8–4.0, slightly below the isolelectric point of ovalbumin, and at a gas flow of 20 ml/min. The apparatus permits many of the variables affecting foaming properties of proteins, i.e. pH, temperature, ions, carbohydrates and surfactants to be controlled while quantitatively determining foaming properties of small quantities of protein. Copyright © 1979, Wiley Blackwell. All rights reserved