Do Potatoes Have Aflatoxins? Answering the Pressing Question

November 18, 2025 •

4 min read

According to the National Cancer Institute, aflatoxins are a family of toxins produced by certain fungi that contaminate crops like maize, peanuts, and tree nuts. While these mycotoxins are a serious concern in many agricultural products, the question of whether do potatoes have aflatoxins requires a more nuanced answer, especially when considering proper storage and handling.

Quick Summary

This article explores the relationship between potatoes and aflatoxins, clarifying that while not a typical host, improper storage can lead to other harmful mycotoxins. It details the true risks, such as naturally occurring solanine, and provides practical advice for consumers to ensure potato safety.

Key Points

Aflatoxins are Not Found in Potatoes: Potatoes are not typical hosts for aflatoxin-producing fungi, which primarily contaminate crops like corn and peanuts.
Solanine is the Real Threat: The main toxic compounds in potatoes are natural glycoalkaloids like solanine and chaconine, which increase with light exposure or damage.
Discard Moldy Potatoes: Any potato with visible mold should be thrown away, as the mold's toxic filaments can penetrate deep into the tuber.
Proper Storage is Key: Store potatoes in a cool, dark, and well-ventilated area to prevent greening, sprouting, and fungal growth.
Do Not Store with Onions: Keep potatoes away from ethylene-producing produce like onions and apples to prevent premature sprouting.
Toxins are Heat-Stable: Neither aflatoxins (if present) nor glycoalkaloids are reliably destroyed by cooking, making removal of affected portions critical.
Peel and Remove Green Parts: Peeling or cutting away green areas on potatoes can remove most of the solanine concentrated near the surface.

Do Potatoes Have Aflatoxins? An In-Depth Look

While aflatoxins are a serious food safety concern worldwide, especially in hot and humid regions affecting crops like corn and peanuts, potatoes are not typically considered a major host for these specific mycotoxins. Aflatoxins are primarily produced by certain species of the Aspergillus fungus, namely A. flavus and A. parasiticus, which are common soil organisms. Though some studies have used potato dextrose broth as a medium to cultivate aflatoxin-producing fungi in a laboratory setting, this does not indicate that potatoes themselves are a common source of aflatoxin contamination in the field or during normal storage. Instead, the risk of toxins in potatoes is associated with other, more common contaminants and naturally occurring compounds.

The Real Toxin Concern in Potatoes: Solanine and Chaconine

The primary toxic compounds of concern in potatoes are not aflatoxins, but rather glycoalkaloids like solanine and chaconine. These are naturally occurring compounds that act as a defense mechanism for the plant against insects and disease. While typically found at low, safe levels in fresh potatoes, their concentration can increase under certain conditions, posing a health risk.

Green Patches: Exposure to light causes potatoes to produce chlorophyll, turning the skin green. This greening often indicates a correlated increase in glycoalkaloid levels. While the chlorophyll itself is harmless, the associated rise in solanine can be problematic.
Sprouting: As potatoes age and begin to sprout, the concentration of glycoalkaloids also increases significantly, especially in the sprouts and surrounding tissue. Sprouted potatoes should have the sprouts removed completely before use.
Bruising and Damage: Physical damage or bruising can stimulate the potato to produce more glycoalkaloids as a protective response. This is why discarding bruised or damaged portions is recommended.

Are There Other Mycotoxins Found on Potatoes?

Yes, other fungi can affect potatoes, which may produce different types of mycotoxins. For example, Fusarium species are common fungal pathogens of potatoes that can cause dry rot and produce mycotoxins. The appearance of any mold, regardless of the type, indicates that the potato is spoiled and should be discarded. Unlike hard, non-porous vegetables where mold can be cut away with minimal risk, the porous nature of potatoes allows mold filaments to penetrate deep below the surface. Removing the visible mold does not guarantee the removal of the fungal root system or any associated toxins.

How Proper Storage Prevents Contamination and Toxin Buildup

Correct storage is the most effective way to prevent fungal growth and inhibit the production of natural potato toxins. The key is to control environmental factors such as light, temperature, and ventilation.

Here are the recommended storage practices:

Keep Dry: Do not wash potatoes before storing them. The added moisture can promote mold and bacterial growth.
Maintain Proper Airflow: Store potatoes in a well-ventilated container, such as a paper bag, wire basket, or mesh sack. Avoid sealed containers like plastic bags, which trap moisture.
Ensure Darkness: Store potatoes in a cool, dark place, away from direct sunlight or fluorescent lights. This prevents the formation of green spots and the associated increase in solanine.
Control Temperature: An ideal storage temperature is between 45–50°F (7–10°C). This is cooler than room temperature but warmer than a refrigerator, which can cause sugars to convert to starch.
Avoid Other Produce: Keep potatoes away from other fruits and vegetables, particularly onions and apples, which release ethylene gas that can cause potatoes to spoil and sprout faster.

Comparison of Potato Toxins vs. Aflatoxins


Feature	Aflatoxins	Potato Glycoalkaloids (Solanine/Chaconine)
Producing Organism	Primarily Aspergillus species (A. flavus, A. parasiticus)	The potato plant itself (Solanum tuberosum)
Typical Food Host	Corn, peanuts, cottonseed, tree nuts, dried fruits, rice	Potatoes (tubers, leaves, sprouts)
Mechanism	Fungal metabolite produced on the crop, often during post-harvest storage in high heat/humidity	Natural plant defense chemical; concentration increases in response to stress like light exposure or damage
Affected Crops	Prevalent globally in specific grains and nuts, especially in tropical/subtropical climates	Found in all members of the Solanaceae family, including potatoes, tomatoes, and eggplants
Heat Stability	Extremely heat-stable; cooking does not eliminate the toxin	Somewhat heat-stable, but levels can be reduced by high heat and peeling
Consumer Risk	Primarily from eating moldy/spoiled grains and nuts, or products from animals fed contaminated feed	From consuming green, damaged, or sprouting potatoes, which increases concentration

The Takeaway for Consumers

For the average consumer, the risk of encountering aflatoxins in properly stored and handled potatoes is negligible. The primary concern is not aflatoxins but the naturally occurring glycoalkaloids, solanine, and chaconine, which increase in concentration with improper storage or spoilage. Practicing good storage hygiene and inspecting potatoes before use are the best preventive measures. Any potato with visible mold, green patches, or sprouting should be discarded entirely. This simple practice mitigates the risk of ingesting harmful toxins and ensures food safety. If the potato is firm and free of visual blemishes, the risk is minimal.

Conclusion: The Absence of Aflatoxin Risk in Potatoes

The confusion surrounding the presence of aflatoxins in potatoes stems from misinterpreting fungal growth on other, more susceptible crops. Scientific evidence confirms that aflatoxins are not a concern for potatoes in a normal consumption context. The true risk lies with the plant's own defenses and other common molds that thrive in poor storage conditions. By understanding the real threats and taking simple steps like proper storage and inspection, consumers can enjoy potatoes without fear of aflatoxin contamination. The best defense is vigilance: inspect your potatoes for signs of damage or spoilage, and store them correctly to prevent any issues.

Frequently Asked Questions

No, potatoes do not produce aflatoxins. These toxins are secondary metabolites of specific fungi, primarily Aspergillus species, which are known to contaminate crops like corn, peanuts, and certain nuts, not potatoes.

No, you should not eat a potato with mold. Because potatoes are porous, mold filaments can spread deeply into the flesh, and the toxins they produce are often heat-stable. Removing the visible mold does not guarantee the potato is safe to eat.

A potato turns green from exposure to light, which increases the production of chlorophyll and, more importantly, the toxic glycoalkaloid solanine. While small, faint green patches can be peeled away, heavily green potatoes or those with a bitter taste should be discarded.

The primary toxin risk in potatoes comes from naturally produced glycoalkaloids, specifically solanine and chaconine. These compounds act as a natural defense mechanism for the plant and can cause harm if consumed in high concentrations, typically found in green or sprouting potatoes.

Store raw potatoes in a cool, dark, and well-ventilated location, such as a paper bag in a pantry or basement. Avoid washing them until you are ready to use them and keep them away from other produce like onions and apples.

Cooking does not reliably destroy glycoalkaloids like solanine. While high heat might reduce levels slightly, peeling away green and damaged parts, as well as sprouts, is the most effective removal method. The toxins are relatively heat-stable, and the safest approach is to remove the affected areas entirely.

You can remove and discard the sprouts and any surrounding green parts before using a potato, as the sprouts contain a high concentration of toxins. However, if the potato is soft, shriveled, or has numerous sprouts, it is best to discard it entirely.