INVESTIGATION OF THE FOAMING PROPERTIES OF SOME FOOD PROTEIN PREPARATIONS

Abstract

The foaming properties of 10 different protein isolates and protein preparations (wheat germ-, barley germ-, maize germ protein, lentil-, pea-, soy protein, ovalbumin, bovine serum albumin = BSA, casein and lysozyme) were investigated using volumetric and conductometric methods. According to the volumetric method casein and BSA had the best foaming power. Good foaming power was observed with maize germ-, soy-, pea-, barley germ proteins and ovalbumin. The foam forming ability of wheat germ protein and lysozyme was the lowest. On the basis of conductometric results the proteins investigated may be divided in to the same three groups: However, within the group some changes in the order of proteins may occur. In calculating the linear correlation between the two methods an improvement of correlation (r = 0.93) was achieved by modifying the evaluation of conductometric curves. Maize germ-, soy and lentil protein showed the best foam stability and barley germ protein the lowest one according to conductometric results. The correlation between the foam stability data obtained by the two methods is very poor.