The Scientific Reason Frozen Bananas Taste So Sweet

The banana, everybody's favorite self-packaged grab-and-go snack, comes in many delicious forms. Whether you're slipping it into your gym bag, enjoying some slices with diner pancakes, using a few to make healthier ice cream, or flambéing one for a foster, most people can agree — no good banana should go to waste.

While not as fickle as the beloved avocado, bananas do seem to go from unripe to eat-me-now to worthy of banana bread only pretty quickly. If you're not up for donning an apron and whipping up a batch of baked goods, the simplest solution to not waste a bunch of browning bananas is to pop them in the freezer for a breakfast smoothie at a later date.

If you've ever snuck a bite of that defrosted banana as you're mashing it up for your bread or muffins, you may have noticed it tasted a little bit like a saccharine glob of mush. As it turns out, there's a scientific reason for that. So why do frozen bananas taste so sweet?

As a banana ripens and changes from green to yellow and finally turns brown, starches are broken down into sugar by an enzyme known as amylase. According to a research article published in the Global Journal of Nutrition & Food Science in 2022, this starch-to-sugar conversion is responsible for softening the fruit and increasing its sweetness as it ripens. This is why a brown-spotted banana tastes more like dessert than a green-tipped one and why overripe bananas are best suited for sweetening baked goods. This same amylase enzyme is present in our saliva and has an important job of beginning the breakdown of carbohydrates into glucose in our mouths, per Alton Memorial Hospital. 

Once you pop that banana in the freezer, the water present in its flesh freezes. The frozen water starts to break open the cells of the banana, distributing both the enzyme and stored starches throughout the fruit in the process. When you remove the banana from the freezer, the amylase diffused in the freezing process starts to convert the starch diffused in the freezing process into sugar, thus making the defrosted frozen banana sweeter on the tongue (via Fine Dining Lovers).