Delicious potatoes in summer are rich in nutrients such as vitamin C, potassium, phosphorus, and iron. They are highly versatile and used as ingredients in various dishes. Sometimes, when preparing potatoes, you may notice that the skin has turned green. In such cases, you might worry about whether it's safe to eat the potatoes. Is it okay to consume them?

Potatoes usually turn green when exposed to sunlight for a long period because chlorophyll synthesis occurs.

This phenomenon where potatoes turn green is called "greening." Potatoes are crops that develop from thickened underground stems, which form potatoes. When these stems are underground, they form potatoes, but when exposed to sunlight, they do not form potatoes and instead turn directly into stems. This is due to chlorophyll synthesis. Even without sunlight, prolonged exposure to artificial light can cause potatoes to turn green. The reason why potatoes are often covered with newspaper at supermarkets or markets is also due to this. Greening usually occurs immediately after harvest, during storage, or during distribution.

The problem is that when potatoes are sprouted, the content of the toxic substance solanine increases. In particular, the glycoalkaloid compounds in solanine cause a bitter taste. The bitterness varies depending on the degree of sprouting, and high concentrations of glycoalkaloids can cause nausea and allergic reactions. According to the 'Washing and Packaging Technology to Reduce Sprouting and Decay' by the National Institute of Food and Drug Safety, glycoalkaloid components produce the characteristic aroma and bitter taste of potatoes at low levels (below 15 mg/100g FW), but at high concentrations, they can lead to nausea, coma, and even death. The U.S. Food and Drug Administration strictly limits glycoalkaloid content to 20 mg/100g FW or less. The same applies to sprouted potatoes. It is known that sprouted and discolored potatoes have solanine levels more than ten times higher than regular potatoes.

It is safer not to eat potatoes that have turned green or sprouted.

Solanine is resistant to heat and does not easily disappear even after cutting away discolored areas or sprouts and cooking in hot water. When storing potatoes, they should be kept away from prolonged exposure to sunlight or artificial light. After purchasing, storing potatoes in black bags, newspaper, or boxes can help keep them fresh for a longer period. The appropriate storage temperature is between 7 and 10 degrees Celsius, and when stored at room temperature above 10 degrees Celsius, it should not exceed one week.

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Storing potatoes is really difficult.

When you dig up potatoes for the first time

It can turn green when exposed to sunlight.

So, I store it in newspaper or in a shaded place.

These days, I store them by putting newspapers inside cardboard boxes.

The sprouts have come out, so I need to tidy up.