Chemists Hacked Ice Cream With Banana Trash to Make a Melt-Proof Scoop

It's low-fat, to boot!

Trabajando en Ps nº2

Tuesday marked the first day of spring in the northern hemisphere, reminding us all that ice cream weather is on the way (if the nor’easters ever stop coming). With all the snow, it may be hard to imagine temperatures so hot they make your scoop melt, but chemists presenting at the 255th National Meeting & Exposition of the American Chemical Society want to let you know: when the time comes, they’ve got you covered.

In their presentation, the scientists from Colombia’s Universidad Pontificia Bolivariana, who are no doubt accustomed to much more ice cream-friendly weather, reported that they’ve found a way to make eating the frozen treat less messy using a compound from the banana plant.

“Our findings suggest that cellulose nanofibers extracted from banana waste could help improve ice cream in several ways,” study leader Robin Zuluaga Gallego, Ph.D., said in a statement published Wednesday. “In particular, the fibers could lead to the development of a thicker and more palatable dessert, which would take longer to melt. As a result, this would allow for a more relaxing and enjoyable experience with the food, especially in warm weather.”

Monsieur Crémeux
No more of this!

The fibers in question come from the stem of the banana plant. Not the nubbin on the end of a single fruit; rather, the long, woody stalk from which a bunch of bananas grow, which most people don’t encounter often. These stems — known as rachis — make up a big proportion of waste from banana harvesting. “Once a bunch arrives at the packaging plant, the bunch rachis becomes residual biomass too,” Spanish scientists pointed out in 2016. Zuluaga Gallego’s ice cream fix could kill two birds with one stone, improving ice cream and recycling waste at once.

rachis banana plant
The 'rachis' contains cellulose fibers that can help keep ice cream scoops intact.

Zuluaga Gallego and his colleagues discovered that grinding up the rachis released a form of cellulose that is useful for improving ice cream’s texture. Cellulose is the chemical compound that makes up the tough walls of all plant cells, making them sturdier than animal cells.

What the team extracted from the ground-up rachis were cellulose nanofibrils, nano-sized forms of this compound that are thousands of times smaller than the width of a human hair. When added to ice cream, the researchers found that the nanofibrils offered the sought-after architectural support required in hot weather.

Herbaceous Dicot Stem: Collenchyma in Hypodermis of Older Helianthus
Cellulose in the walls of plant cells provide structural support; it appears to do the same for ice cream.

The cellulose fibrils do more than prevent drips. When added to low-fat ice cream, the results seemed creamier and better textured, which is thought to be a result of a better-stabilized fat structure. Fat is much maligned but important in making ice cream, as the dessert gets its light-yet-creamy texture when just enough air is trapped in its matrix of fat molecules; as Serious Eats explained in 2015, “Part of the churning process is whipping air into a mixture that’s full of cream, and the more cream you add to your ice cream base, the lighter and more aerated it’ll be.” The cellulose nanofibrils seem to make it possible to improve ice cream texture without having to add extra fat, undoubtedly a boon for health-conscious dessert lovers.

What remains unclear, for now, is what the cellulose nanofibril ice cream actually tastes like. Flavor is paramount if Zuluaga Gallego and his team want their invention to take off, as they’ve got some competition. In 2017, Japanese scientists announced they’d made a melt-proof ice cream using polyphenols from strawberries — which, by many accounts, was still pretty tasty.