You pick up a bunch of small, curly, bright yellow bananas¹ and you take them home. On the way there, however, you remove the one with the label, peel it most of the way down, and in a few quick bites, finish it off.
At your next visit to the store, the display may feature larger, straighter bananas. Sometimes, the bananas you buy are sweet and flavorful. At other times, they are starchy. So why are some bananas sweeter than others?
Bananas are grown and used for different purposes. For some, fried in a skillet, starchiness is a desirable quality. Others are sold for their sweetness and aroma. The currently most popular form of the latter is the dessert, or Cavendish banana (Musa acuminata ‘Williams’).
Processing the Cavendish Banana
Bananas do not grow on trees, but are herbaceous plants. Oddly enough, the banana is, officially, a berry. Dessert bananas are harvested in the “mature green” state. After shipping, they are ripened using ethylene gas² in special rooms that feature humidity control. The process induces a bright yellow color. In fact, if temperatures are too low, a gray tinge results that indicates an inferior product.
Flavor and the Individual Fruit
Since the most common banana found in most U.S. stores is but one variety—the Cavendish—what is it that distinguishes the sweetness and flavor of one batch over another? In general, the Cavendish banana is sweetest when the fully yellow skin has just a few brown spots.
Flavor and Sunlight
First, some bunches of banana are much more curved than others. This is because bananas, at an advanced stage in their development, reach toward the sun. Bananas exposed most to the sun are more highly curved than those receiving less sunlight.
This could account for a marginal increase in sugar content and resulting fruit sweetness, since sunlight is part of the maturing and ripening process in which starch is converted into sugar.
The Primary Factor
Since most of the ripening process does not occur on the plant, the bulk of the variance in color, flavor, sweetness, and texture would come from the quality of processing a batch of bananas receives in that “special room” at its ship-to location.
¹ Actually there is a host of varieties of banana or plantain. We discuss here the classic eating banana, found in U.S. grocery stores for many decades.
² Ethylene gas is produced in nature by bananas, so it would be unfair to suggest the commercial process is entirely artificial.
- UC, Davis: Banana: Recommendations for Maintaining Postharvest Quality
- Purdue University: Banana
- Universiti Putra Malaysia: Plastid Ultrastructure…