An international team of scientists from Colombia and Canada has found that adding a fibrous extract from banana fruit stems (rachis) to ice cream could slow melting, increase shelf life and potentially replace fats used to make the tasty treat.
Cellulose nanofibrils affect the colloidal network structure of ice cream. Image credit: Jonny Lindner.
Despite its popularity, ice cream does have some drawbacks that food scientists have struggled to overcome.
Most obviously, it can melt when exposed to heat. In recent years, researchers have tried using wood pulp extracts to tackle this issue.
In 2017, a research team in Japan developed a melt-resistant ice cream based on polyphenol compounds found in strawberries.
Dr. Robin Zuluaga Gallego from the Universidad Pontificia Bolivariana and co-authors have been investigating a different approach using banana plants.
In particular, the scientists wanted to determine if they could slow down melting and extend the shelf life of ice cream using a fibrous extract from banana rachis.
“Our findings suggest that cellulose nanofibers extracted from banana waste could help improve ice cream in several ways,” Dr. Zuluaga Gallego said.
“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.”
The team extracted cellulose nanofibrils (CNFs), which are thousands of times smaller than the width of a human hair, from ground-up banana rachis.
Then the researchers mixed the CNFs into ice cream at varying concentrations, ranging from zero up to three-tenths of a gram per 100 grams of the dessert.
Using a variety of analytical tools, they evaluated the effects that CNFs had on the popular frozen treat.
They found that ice creams mixed with CNFs tended to melt much more slowly than traditional ice creams.
They also determined that CNFs could increase shelf life of ice cream, or at least decrease its sensitivity to temperature changes that occur when moved to and from the freezer.
In addition, CNFs increased the viscosity of low-fat ice cream, which improved the creaminess and texture of the product.
“This suggests that CNFs could help stabilize the fat structure in ice creams. As a result, CNFs could potentially replace some of the fats — and perhaps reduce calories — in these desserts,” said co-author Dr. Velásquez Cock, also from the Universidad Pontificia Bolivariana.
Moving forward, the scientists plan to explore how different types of fat, such as coconut oil and milk fat, affect the behavior of CNFs in other frozen treats.
They presented their results March 21 at the 255th National Meeting & Exposition of the American Chemical Society in New Orleans, LA.
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Jorge Andres Velasquez et al. 2018. Cellulose nanofibrils in ice cream: An analysis of its influence in the matrix structure. 255th ACS National Meeting & Exposition, abstract # CELL 343
