Do bananas go bad?

In this brief guide, we will address the query, “do bananas go bad?” We will also discuss what is the shelf life of bananas and how you should store them to last longer.

Do bananas go bad?

Yes, bananas go bad. Like any other perishable good, after some time, bananas will go bad eventually. The production of ethylene is one of the main factors that lead bananas to go bad since they ripen faster (1,2). But do not panic, ripe bananas can be used to prepare delicious homemade banana bread.

How long do bananas last?

Depending on the place you choose to store your bananas, their shelf life will vary. Let’s take a look.

  • If you leave your bananas at room temperature, they can go bad in about 3 to 8 days. If you live in a warm environment, storing bananas in the pantry can cause the shelf life to reduce drastically (3,4).
  • Storing bananas in the fridge will give you more time to enjoy their flavor as they will be good for up to 9 days (3).
  • If you require it to preserve bananas for a longer period, freezing is the way to go. Storing your fruit in the freezer can enlarge its shelf life for up to 12 months (5).

So, depending on your needs, feel free to choose the storage you want. As you can tell, when stored in the fridge, the shelf life only increases a day, if you do not have space in the fridge, do not worry and leave them unrefrigerated.

What causes bananas to go bad?

The ripening process that occurs naturally is the main reason why bananas go bad. Ethylene gas is produced by bananas when they ripen, accelerating the fruit’s internal chemical processes, as a result, the banana’s enzymes convert complicated molecules into simpler ones, softening the texture and sweetening the fruit (2,6).

This natural process might advance more quickly than desired if left unattended for an extended period of time or stored poorly (such as in direct sunlight or in a warm environment), leading to overripe bananas that can turn mushy or acquire dark spots on their skin (2,6).

The presence of fungus is another factor that can cause bananas to go bad, causing diseases, such as anthracnose and crown rot. Fungal species commonly found in bananas include Colletotrichum, Fusarium, Acremonium and others (1).

How to store bananas?

The recommended storage for bananas will vary depending on their ripening stage. If they are green, the optimum temperature to store is at 13 to 14 ºC (56 to 58 ºF) (7).

Once bananas have ripened, they need to be kept under refrigeration at all times, this will enlarge their shelf life. If your bananas have completely turned brown, they should be used as soon as possible (8). 

If time is winning, you can preserve overripe bananas for later, all you need to do is to wrap them in plastic wrap, and then place them in the freezer, you can use them to prepare delicious recipes! (5).

How can you tell when bananas have spoiled?

Ripe and overripe bananas are different from rotten bananas. When bananas exhibit several signs of spoilage, it means they are no longer safe to be consumed. Make sure you check for any of these indicators before using stored bananas, such as (1,2,9):

  • Squishy texture. If you squeeze bananas and they go all squishy, it means they have started to rot. However, sometimes you do not even need to squeeze them. Just by looking at them, you can notice when they have gone bad.
  • Production of slimy fluids. If you notice bananas have started to leak a slimy fluid, it is not advisable to eat them. 
  • Fermented and moldy odor. Just by taking a quick sniff at your bananas, you can tell when bananas have rotten. Avoid consuming any type of moldy foods, and do not try to remove them and eat the rest. Mold can still be present and can cause intoxication.
  • Your whole banana has turned brown. If there are not any yellow spots left on your bananas, it might be a sign that they are starting to spoil. In most cases, they will not have negative consequences, but avoid doing so!

What happens if you consume bad bananas?

Eating bad bananas can cause foodborne illnesses with symptoms like (10):

  • nausea
  • vomiting
  • stomach cramps
  • diarrhea

Spoiled bananas may harbor harmful microorganisms and toxins, including bacteria, such as Salmonella and E. coli, and molds like Aspergillus and Penicillium species, which can lead to gastrointestinal discomfort and foodborne illnesses such as salmonellosis or mold-related allergies caused by mycotoxins (11,12). 

Be cautious and avoid consuming visibly spoiled bananas, and if severe symptoms or prolonged illness occur after eating rotten bananas, seek medical attention.

Conclusion

In this brief guide, we have addressed the query, “do bananas go bad?” We have also discussed other queries related to the subject at hand. 

Hope you found this blog useful. If you have any questions, please let us know.

References 

1. Khan, S., Rafat, S. To study the Postharvest diseases of Banana. Conference: National beed, 2018. 

2. Murm, S.B., Mishra, H.N. Post-harvest shelf-life of banana and guava: Mechanisms of common degradation problems and emerging counteracting strategies. Innov Food Sci & Emerg Technol, 2018, 49,20-30.

3. Singh, A.K., et al. Effect of different packaging materials on shelf life and  quality of Banana cultivar var. cavendish. The Pharma Innovation Journal,  2021, 10(12): 113-116.

4. Hailu M, Seyoum Workneh T, Belew D. Effect of packaging materials on shelf life and quality of banana cultivars (Musa spp.). J Food Sci Technol. 2014, 51(11):2947-63

5. Silva, C.L.M. Home Freezing of Fruits and Vegetables. In book: Frozen food science and technology, 2008.

6. Jin Gao, et al. Role of ethylene response factors (ERFs) in fruit ripening. Food Quality and Safety, 2020, 4, 15–20.

7. The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks. Agricultural Research Service Agriculture, Handbook Number 66, 2016, 224-225.

8.  Bantayehu, M. Fruit ripening and postharvest life of banana varieties at different temperatures and packaging. J Postharvest Technology, 2017, 05(1): 30-42.

9.  Porat, R. Fallik. E. Production of off-flavours in fruit and vegetables under fermentative conditions. Fruit and Vegetable Flavour, 2008, 150-164.

10. What You Need to Know about Foodborne Illnesses. FDA, 2022.

11. Ramavat, S., Ahuja, M. Microbial examination of spoiled bananas packed in polythene bags. Asian Jr. of Microbiol. Biotech. Env. Sc. 2020, 22, 2020:509-512

12. S.M. Yahaya, et al. Fungal infection of banana (musa sapientum) sold at wudil and yanlemo markets of kano state. Dutse Journal of Pure and Applied Sciences (DUJOPAS). 2018, 4, 254-262.

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