Swiss scientists create novel process for foams that last ‘essentially forever’

Ever-lasting foam in ice cream or beer without artificial stabilisers? Swiss researchers have “for the first time” developed a novel strategy to make foam bubbles last “essentially ‘forever.” From a sensory point of view, bubbles are important. From a light frothy foam in beer to a light, creamy ice cream that melts in the mouth for a fluffy dough, it is the structure of the bubbles that creates the texture. From a food technologist’s point of view, however, they are inherently unstable: sinking, merging, popping and changing the structure of the food matrix. A team of Swiss researchers backed by Nestlé Research Centre, have developed a method for determining bubble strength and structure that could lead to big savings on stabilisers – or being able to swap artificial stabilisers for natural ones – and longer-lasting foams. Ostwald ripening, named after the German chemist and 1909 Nobel prize winner, is when large bubbles become larger while smaller ones shrink and then disappear – extremely difficult to stop or even slow down. Once the bubble ‘ripening’ beings, it compromises the long-term stability of the foam and surface-active components, such as protein in beer foam, only slow this process down in the short term. “Compared to surfactant-stabilised system we gain orders of magnitude or even make the foam last essentially ‘forever’. It could be made such that it would just remain stable and not coalesce or ripen. If there is no mechanical force exerted, it would just stay there.” Post-doctoral researcher in the team, Peter Beltramo, said the findings would help industry “save a lot of materials and thus reduce costs”. However, Nestlé’s interest in the project was less about cutting costs than cleaning up the labels, particularly for its ice cream portfolio, which sparked the study. The Swiss company is currently rolling out a clean label initiative, dubbed ‘Kitchen Cupboard’, which replaces artificial ingredients with “ingredients consumers can understand and feel good about when reading the back-fo-pack list.” This means simple spices, vegetables, herbs, salt, oils, flours, starches and natural flavours, or ingredients created through basic culinary processes such as fermentation and roasting.