Old false claims that it is easy for shoppers to spot whether bananas have been “chemically ripened” are resurfacing, even though it is impossible to assess with the naked eye how a banana matured. Brown spots occur on bananas, regardless of the ripening method. Black stems may be a sign of fungus-caused rot on the fruit.
The claim that “green stalk with brown spots means they were chemically ripened. Black stalk...Naturally ripened” goes back many years and has been labelled false by other fact-checking organizations here and here .
Most bananas are exported from countries such as Ecuador and the Philippines while they are still green and then ripened at their destinations.
To ripen, all bananas need the airborne hormone ethylene, which they produce on their own. Throughout their banana-eating history, people have found ways to induce ripening, such as trapping the ethylene gas by putting the fruit in a sealed bag ( here ). In the United States both conventionally and organically grown bananas ( here ) are frequently placed in temperature-controlled “ripening rooms” that pump ethylene over the fruit, turning them soft, sweet and ready to eat. This is what most people mean when they say “chemically ripened.” Other ripening agents such as acetylene (an ethylene analogue) or smoke from burning semi-dried leaves are available, but they are not nearly as popular and have more limited use ( here ). Or, bananas can be left to ripen on their own, “naturally.”
There is no way a consumer picking through bunches at the store could tell which ripening method had been used.
Bananas that have matured on their own resemble ones that have been pushed to ripen, with a 2019 article here in the International Journal of Food Science finding that “most studies suggest that there is no difference in biochemical composition and sensory quality in bananas treated with chemicals that induce ripening from naturally ripened bananas.”
Brown spots are simply an indicator of “advanced ripeness” and indicate a banana, however it matured, is “at the peak of its sweetness” (here) . As the U.S. Department of Agriculture explains here the spots can also appear if the bananas were in a high temperature and overheated. Bruised bananas may have spots, as well ( here. )
Meanwhile, black stalks and stems do not show a banana has been “naturally ripened.” Photos published here by the Postharvest Center at the University of California at Davis, a leader in agricultural research, show that bananas with green stems are in the first four stages of ripeness. But bananas with black stems may be experiencing “crown rot,” a disease caused by one of four fungi. This is a disease that develops “as the fruit is being stored and ripened in the marketing chain” (here ). The fungus can travel into the fruit but so far a direct link between crown rot and human pathogens “has not yet been established” (here ).
False. Consumers cannot judge whether bananas were “chemically” or “naturally” ripened by looking at them.
This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here .
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