Samples containing the highest concentration of WPC had the lowest density, and accordingly had the highest foaming capacity. This corresponds to the low liquid volume fraction (ϕ) contained in the foam (0.154–0.119) ( Table 2). Some of these values were higher than those obtained for enriched WPC–milk foams (0.13–0.07) ( Martínez-Padilla et al., 2014). Similar ϕ (∼0.13–0.14) were reported for foams prepared with whey proteins ( Oboroceanu et al., 2014) and for WPI with sugar ( Pernell et al., 2002). However, in WPC (8%) and XG (2%) foams, a very high ϕ (∼0.51) was reported ( Liszka-Skoczylas et al., 2014), possibly due to the high concentration of XG used (high density and very high viscosity).