Interfacial and foaming properties of plant and microbial proteins: Comparison of structure-function behavior of different proteins

Many plant proteins are amphiphilic molecules that can adsorb to air-water interfaces and form protective coatings around gas bubbles. In this study, the composition, structure, physicochemical properties, air-water interfacial properties, and foaming properties of 16 plant and microbial proteins were characterized. We found a correlation between the composition, structure, physicochemical properties, and foaming properties of the proteins. The foaming capacity of them showed a highly significant positive correlation (p <= 0.01) with their foaming stability, alpha-helix content, surface hydrophobicity, and free sulfhydryl content. The foaming capacity and foaming stability showed highly significant negative correlations with disulfide bond content (p <= 0.01). We found wheat gluten protein (WGP) and mung bean protein (MBP) had higher foaming capacity (102.67 +/- 8.08 % and 89.33 +/- 4.72 %), which could be attributed to higher surface hydrophobicity (179.68 +/- 1.40 and 130.28 +/- 1.41) and larger contact angle (82.369 +/- 0.016 degrees and 82.949 +/- 0.228 degrees).