- Swiss researchers claim they have developed a process for making foam bubbles last "essentially forever," according to the Dairy Reporter.
- The development has potential benefits for the food industry since it could reduce the need to use artificial stabilizers in beer, ice cream and other products, or allow manufacturers to use natural stabilizers instead.
- Lead scientist Jan Vermant of the Swiss Federal Institute of Technology in Zurich said the discovery could prevent or stop Ostwald ripening, which is when large bubbles grow larger and smaller ones shrink and disappear. "Compared to surfactant-stabilized system we gain orders of magnitude or even make the foam last essentially ‘forever,' he said. "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."
The team of researchers, with support from the Nestle Research Center and other sources, noted in the study report that "structured materials" such as ice cream must remain stable over long shelf lifetimes. They found that, until now, how bubbles and emulsions are stabilized had been unclear so control over the process wasn't possible.
The scientists used a particle stabilizer to coat individual bubbles and then exposed them to pressure changes, which meant they could determine when the bubbles would begin to shrink and then collapse. Stabilizers create a "net-like structure" over the bubble to protect it, but even those bubbles partially coated might be as stable as the others, so it becomes easier to predict how much stabilizer is required. These "armored" bubbles create foam and emulsion materials with stable microstructures and controllable textures, the scientists reported.
What prompted the study was Nestle's initiative to clean up its ice cream labels. "Kitchen Cupboard" is the company's strategy to replace artificial ingredients with those consumers can understand and feel good about. It also means using ingredients created in ways that are understood.
For its Häagen-Dazs brand, the Swiss consumer products giant rolled out a massive advertising campaign in cities such as New York, Los Angeles and Washington, D.C., featuring a spoonful of ice cream and the slogan: “5 ingredients, one incredible indulgence." Nestle also introduced a new Coffee Mate creamer with all-natural ingredients and took out artificial flavors and reduced sodium across its pizzas and snacks, including its Tombstone and Hot Pockets brands. The new foam could be a way to further deepen its commitment to clean labels, while giving consumers more of what they want in their favorite products.
Nestle — and other ice cream manufacturers — could take a big step down the clean label path if they could substitute natural ingredients, such as protein or fiber particles, for the artificial stabilizers commonly used for slowing ice crystal growth, preventing shrinkage during storage and reducing the rate of meltdown. Typical stabilizers used in the industry are guar gum, locust bean gum, xanthan, gelatin and carrageenan.
It's easy to see how ice cream and beer makers might benefit from these findings, but the study's lead scientist noted that how fast the process could be adapted in the wider food industry depends on the state of the knowledge about food-grade particles.