Potatoes are a staple food worldwide, known for their versatility and nutritional value. Potatoes can undergo various changes in appearance, developing growths or discolorations. Understanding these changes is important for determining edibility and safety. This article explores common alterations, their causes, and what they signify for your food.
Understanding Potato Sprouts
Potato sprouts, often referred to as “eyes,” are shoots that emerge from the potato as it begins to germinate. This natural process occurs when potatoes are exposed to light, warmth, and sufficient time.
The primary concern with sprouted potatoes is the presence of glycoalkaloids, specifically solanine and chaconine, natural toxins. While fresh, unsprouted potatoes contain low, safe levels of these compounds, their concentration increases significantly in the sprouts and the area immediately surrounding them. Consuming high amounts of these toxins can lead to gastrointestinal upset, including nausea, vomiting, and abdominal pain.
If sprouts are small (1-2 cm) and the potato remains firm, they can be safely removed by snapping them off or cutting them out with a peeler, along with any soft spots. However, if sprouts are extensive, long, or the potato is shriveled and soft, the entire potato should be discarded.
The Green Hue of Potatoes
Potatoes can develop a green color, particularly when exposed to light during storage or growth. Greening is due to chlorophyll production. While chlorophyll is harmless, its presence often indicates an increased concentration of solanine, a toxic glycoalkaloid.
Solanine formation is triggered by light exposure. Ingesting solanine can cause symptoms such as nausea, headaches, and digestive issues.
If a potato shows minor greening, especially near the skin, the affected green portions should be peeled or cut away, as the highest concentration of solanine is typically found directly beneath the skin. However, if the green color is extensive, deep, or the potato tastes bitter, the potato should be discarded.
When Mold Appears on Potatoes
Mold on potatoes is a fungal growth that typically results from excessive moisture and improper storage conditions. Mold appears as fuzzy patches of different colors.
The primary concern with moldy potatoes is the potential production of mycotoxins, toxic compounds produced by fungi. Unlike some foods where mold can be simply cut away, potatoes are porous, meaning mold spores and their associated toxins can spread throughout the tuber beyond what is visibly apparent.
Therefore, if mold is discovered on a potato, discard the entire potato to avoid potential health risks from mycotoxins.
Proper Potato Storage
Proper potato storage prevents sprouts, greening, and mold, extending their shelf life. Potatoes should be kept in a cool, dark, and well-ventilated environment.
An ideal temperature range for storage is typically between 43°F (6°C) and 50°F (10°C), which slows down sprouting and greening without converting starches to sugars. Darkness is important because light exposure directly triggers both chlorophyll and solanine production, leading to greening.
Storing potatoes in paper bags, mesh bags, or open bins promotes air circulation, which is essential to prevent moisture buildup that encourages mold growth. Avoid storing potatoes in airtight plastic bags. Store potatoes separately from fruits like apples, bananas, and onions, as these produce ethylene gas that can accelerate potato sprouting.