Bananas turning brown in the freezer is a natural and common occurrence. When bananas are exposed to freezing temperatures, the water inside the fruit's cells expands and forms ice crystals. These ice crystals damage the cell walls and cause the fruit to become mushy and brown once thawed.
Additionally, bananas contain enzymes, such as polyphenol oxidase, that are responsible for the browning process. Although freezing slows down the enzymatic activity, it doesn't completely stop it. As a result, when the bananas are thawed, the enzymes become active again, leading to the browning of the fruit.
To prevent bananas from turning brown in the freezer, you can try the following methods:
Peel and slice the bananas before freezing: By peeling and slicing the bananas into smaller pieces, you can minimize the damage caused by freezing and reduce the browning when thawed.
Use freezer-safe containers or bags: Ensure that the bananas are stored in airtight, freezer-safe containers or bags to prevent freezer burn and minimize exposure to air.
Coat the bananas with lemon juice: Lemon juice contains citric acid, which can help slow down the browning process. Before freezing, you can dip the banana slices in lemon juice or toss them in a mixture of lemon juice and water.
Consider using the frozen bananas for baking or smoothies: While the texture of frozen and thawed bananas may not be suitable for eating as is, they can still be used in baking recipes or blended into smoothies. The browning will be less noticeable in these applications.
Remember that frozen bananas are safe to eat even if they turn brown, as long as they have been stored properly and are not spoiled or rotten. The browning is primarily a visual change and does not indicate that the bananas are no longer edible.