Understanding Solanine: What Vegetable Has the Most Solanine and How to Handle It Safely?

December 8, 2025 •

3 min read

Green or sprouted potatoes can contain dangerously high concentrations of the glycoalkaloid solanine, which is naturally produced by nightshades as a defense mechanism. These high levels can be toxic if consumed, but with proper knowledge, it is easy to avoid. This guide explains what vegetable has the most solanine and how to practice safe food handling.

Quick Summary

Green potatoes and sprouts contain the highest, most toxic levels of solanine. Light exposure and physical damage drastically increase these concentrations. Proper storage and peeling can significantly mitigate this risk.

Key Points

Green Potatoes Contain the Most Solanine: The highest concentrations of solanine occur in potatoes that have turned green due to light exposure or have begun to sprout.
Solanine is a Natural Defense: As a nightshade plant, potatoes produce solanine as a protective measure against pests and disease.
Cooking Does Not Destroy Solanine: High temperatures from boiling or baking do not break down solanine effectively, so removing affected parts is essential.
Proper Storage is Key: To prevent solanine build-up, store potatoes in a cool, dark, and dry place, and avoid physical damage.
Recognize Warning Signs: A green tint under the skin or a bitter taste are clear indicators of high solanine levels and a signal to discard the affected potato.
Other Nightshades are Less Risky: While other nightshades like eggplant and ripe tomatoes contain glycoalkaloids, their levels are significantly lower and pose minimal risk in typical consumption.

The Potato: The Primary Concern for Solanine Content

While solanine is present in trace amounts in many nightshade vegetables, the potato is the most significant source of concern for human toxicity. All potato plants naturally produce low levels of glycoalkaloids, including solanine, as a natural defense against pests and disease. However, these levels can increase dramatically under certain conditions. The most common signs of elevated solanine in potatoes are a green tint under the skin and sprouting eyes.

Why Green Potatoes are Dangerous

The green coloring you see on a potato is chlorophyll, which is harmless. However, its presence is a clear indicator that the potato has been exposed to light. This light exposure also triggers the production of solanine, which is colorless. The highest concentration of this toxin is found in the green skin, the layer directly beneath it, and the sprouts. A bitter taste is another, more reliable, indicator of toxic levels. Cooking methods like boiling or microwaving do not effectively destroy solanine. For this reason, it is crucial to properly handle potatoes showing these signs to prevent potential solanine poisoning, which can cause severe gastrointestinal and neurological issues.

Other Nightshade Vegetables and Their Glycoalkaloids

Although the potato is the main edible vegetable to watch out for, other members of the nightshade family contain similar compounds. It is important to distinguish between solanine and other related glycoalkaloids.

Tomatoes (Unripe)

Tomatoes contain a related alkaloid called tomatine, not solanine, which is also a plant defense chemical. Unripe, green tomatoes have significantly higher levels of tomatine than their ripe, red counterparts. As the tomato ripens, the tomatine levels drop substantially, making them perfectly safe to eat. The leaves and stems of tomato plants, however, contain high concentrations and should never be consumed.

Eggplant

Eggplants also belong to the nightshade family and contain glycoalkaloids, including solamargine and solasonine. While present, the levels in cultivated eggplants are generally very low and are not considered a threat in normal consumption quantities. Studies show that an individual would need to consume an extremely large amount of eggplant to reach toxic levels.

Proper Storage and Handling to Minimize Risk

Preventing high solanine levels is simple and depends largely on proper storage and preparation. The best practice is prevention.

Store in the Dark: Keep potatoes in a cool, dark place to prevent light exposure, which triggers solanine production.
Handle with Care: Avoid bruising or damaging potatoes, as this can also stimulate glycoalkaloid synthesis.
Inspect Before Use: Always check potatoes for any green patches or sprouts before cooking. If only small areas are affected, peel them away generously.
Taste Test: If a potato has a noticeably bitter or burning flavor, discard it immediately. This is a reliable sign of high toxicity.

Solanine Levels in Different Conditions


Feature	Fresh, Properly Stored Potato	Green or Sprouted Potato
Appearance	Uniform brown or tan skin	Noticeable green tint, especially near the skin and sprouts
Storage	Cool, dark environment away from light	Exposed to light, warm temperatures
Solanine Concentration	Typically very low, under 0.2 mg/g	Can increase tenfold or more, potentially reaching toxic levels
Safety for Consumption	Safe for consumption	Unsafe; bitterness indicates toxicity
Preparation	No special measures needed	Requires discarding green parts and sprouts, or full discard if widespread
Health Risk	Negligible	High risk of gastrointestinal and neurological symptoms

Common Symptoms of Solanine Poisoning

Accidental ingestion of a high amount of solanine can lead to a variety of symptoms, both gastrointestinal and neurological, typically appearing 8 to 12 hours after consumption.

Gastrointestinal Symptoms

Nausea
Vomiting
Diarrhea
Stomach cramps
Throat burning sensation

Neurological Symptoms

Headache
Dizziness
Confusion
Hallucinations (in severe cases)

Conclusion: Prioritize Prevention for Safe Consumption

While the potato is the vegetable with the potential for the highest solanine levels, it is easily manageable with simple precautions. The risk is not in the vegetable itself, but in improper storage and consumption practices. By storing potatoes correctly and being mindful of any green coloring or bitter tastes, consumers can effectively eliminate any risk of solanine toxicity. As always, for specific health concerns, consulting a medical professional is recommended. This knowledge empowers you to enjoy all the wonderful nightshade vegetables safely while keeping your family healthy.

To learn more about glycoalkaloids, including solanine, visit the National Institutes of Health: Glycoalkaloids of Plants in the Family Solanaceae and Their Health Effects.

Frequently Asked Questions

Solanine is a glycoalkaloid, a naturally occurring toxin produced by plants in the nightshade family, like potatoes, as a defense mechanism against insects and pests.

No, properly stored and fresh potatoes have very low, non-toxic levels of solanine. The risk arises when potatoes turn green or sprout due to light exposure or damage.

Yes, peeling a potato can remove a significant portion of solanine, as the highest concentration is found just beneath the skin, especially in green areas. However, if the potato tastes bitter, it should be discarded entirely.

The most common signs are a green tint under the skin and sprouting eyes. A more reliable indicator is a bitter taste or a burning sensation in the mouth.

Unripe green tomatoes contain a related compound called tomatine, and eggplants contain other glycoalkaloids. However, the levels in commonly consumed portions are generally too low to pose a health risk.

Consumption can lead to solanine poisoning, with symptoms including nausea, vomiting, stomach cramps, headaches, and diarrhea. In severe cases, neurological symptoms can also occur.

No, cooking methods such as boiling, baking, and microwaving are not very effective at destroying solanine. Deep-frying at very high temperatures can reduce it, but removing the green parts and sprouts is the most reliable method.