An experimental design approach to modeling water-free foams

In order to create more eco-friendly products, the industry (such as cosmetics) needs to reduce water consumption, not only in the processing stages but also in the composition of the products themselves. However, water-free products remain challenging, especially in terms of formulation. This paper presents an experimental design approach to model the structure-function properties of natural, biodegradable, and water-free oil foams stabilized with a sucrose ester. In particular, the effects of the sucrose ester concentration and foam-whipping time on foams’ bubble size, size distribution, over-run, and firmness were studied. Also, through surface tension measurements, the bubbles’ surface coverage by the sucrose esters was calculated. In addition, oil/sucrose ester mixtures were prepared at varying mixing temperatures (70, 80, 90, 100 °C) and mixing time durations (1, 5, 24, 72 h) and then whipped causing a direct effect on the foams’ physical properties. The resulting water-free foams had high over-runs (up to 74 %) with a stability of more than 5 months at 25 °C.