Are onions covered with black spots safe, or are they contaminated? If you’re unsure, is it best to err on the side of caution and discard them? In an interview with HT Lifestyle, Bharathi Kumar, nutritionist at Fortis Hospital, Nagarbhavi, Bengaluru, discussed whether black marked onions are safe for consumption. Spoiler alert: It depends. Read this also ₹25″>Is the cheese in your bread pakoras real? Doctor tells the truth about street food prices in viral ‘quality check’ video 25
Are Black Spotted Onions Safe for You?
According to Bharti, black spots are usually caused by a common fungus that thrives in warm, humid conditions. Although it is not the same as the infamous ‘black fungus’ infection, it is still a cause for concern.
He begins by explaining: “Onion peels that are blackened or have a dark, sooty coating are usually caused by surface-fungal growth of organisms such as Aspergillus niger, a common environmental fungus that prefers warm, humid and poorly ventilated storage conditions where it can grow. However, these conditions are less severe due to mucormycetes that are aggressive. ‘Black fungus’ causes infection.
What causes black spots on onion?
According to the nutritionist, “The outer layers of onions become covered with dark, powdery spores that give them a soot or charcoal-like appearance. Fungi usually infect onions when the skin is injured or moisture levels become too high during transportation and storage.”
Bharti said, “The fungi that cause black spots in onions are not harmful in small amounts; however, they can produce ochratoxin A, a mycotoxin that causes toxicity in the kidneys and liver when consumed in large amounts over a long period of time. This toxin is resistant even to moderate heat, so cooking will not necessarily destroy it. This is why proper inspection and storage before any culinary use is extremely important. Is important.”
When to give up onion?
If the dark spots are limited to the outer skin and the inner layers are crisp and white, you can peel off the affected areas and use the rest. However, if the contamination is deep or the onion is soft and mushy, it is best to discard it.
Bharti explained: “From a medical point of view, if the black discolouration is limited to the dry outer papery skin of the onion, and the inner layers remain crisp, white and free of visible black streaks or soft spots, the risk to a healthy person is minimal, provided the onion is thoroughly peeled, washed and cooked promptly. However, this assurance comes with several important precautions.”
The bottom line: A little vigilance goes a long way in keeping your kitchen (and your health) in good condition. Here’s what you need to know:
⦿ Depth of contamination matters. “If the black color penetrates deep into the onion, penetrating through the layers to reach the pulp, or if the onion is soft, moist, mushy or rotting, the chances of mycotoxin formation or growth of more pathogenic species of microorganisms will be even higher. Still, in this case, the onion should be thrown away,” Bharti said.
⦿ At-risk groups need to be more careful, Bharti said, adding, “People who have a weakened immune system, uncontrolled diabetes, chronic lung or liver disease, or are taking immunosuppressant medications should not consume fruits and vegetables that are discolored, moldy, or spoiled in any other way. What might be safe for a healthy adult is still safe for them.” There could be a big risk.”
⦿ Speaking about public perception and myth-busting, he said: “It is important to clarify that the appearance of black layer on onions is not the same as the extremely rare and serious fungal infection mucormycosis (‘black fungus’), which affects internal tissues and is related to completely different conditions. Confusing one with the other creates unnecessary panic.”
⦿ Storage and handling are major preventive factors. According to Bharti, “Onions should be stored in a cool, dry, well-ventilated place, away from moisture, in sealed containers and direct sunlight. Damp, unventilated storage gives fungal spores a chance to germinate, and once the outer layers are compromised, the risk of further spoilage increases.”
They conclude, “For food businesses, restaurants and homes, it is enough to make these few simple checks when purchasing (firm texture, no moisture packed, free ventilation) and use proper storage so that the risk is almost completely eliminated before the onions reach your menu or chopping board in the kitchen.”
Note to readers: This article is for informational purposes only and is not a substitute for professional medical advice. Always seek the advice of your doctor with any questions you may have about a medical condition.
