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Why Do Onions Turn Blue? Here We See Discussion About It

Onions on Table

Why do onions turn blue? As strange as that may appear, there is a very excellent reason behind it. No, seriously. This happens a lot with red onions and shallots, but it may also happen with red cabbage and cherries.

And, happily, there is a method to go backward! Yes, we can turn your onions pink again if they are blue. So let’s look at why this happens, why it happens, and how we may change it.

Anthocyanin, a pigment found in red onions, causes them to become blue. Anthocyanin, a pigment found in red onions, provides a blue-based red. So it can be blue, purple, or red, and it can turn blue when cooked, especially if the end meal is alkaline.

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Why Do Onions Turn Blue?

Anthocyanin, a pigment found in red onions, causes them to become blue. Alkaline components in your meals, such as magnesium and calcium, react with this pigment. Other alkaline elements exist, although they are seldom found in food.

Legumes, almonds, tofu, leafy greens, dairy, and most proteins are high in magnesium and calcium. Anthocyanin, a pigment found in red onions, provides a blue-based red. So it can be blue, purple, or red, and it can turn blue when cooked, especially if the end meal is alkaline.

What Is Anthocyanin and How Does It Work?

Anthocyanin may be found in a variety of foods, including red onions, shallots, and red cabbage. Berries, black rice, and even black or purple vegetables contain it. Don’t think it has anything to do with cyanide. It’s a whole different situation.

Anthocyanin is formed up of the words ‘anther’, which means flower, and ‘cyanine,’ which refers to the color cyan. Because cyan is a fundamental color, you may recall your printer’s seemingly absurd request for ‘cyan’ when it wants to print any color.

The ‘anther’ component refers to the fact that anthocyanin is primarily found in flowers. The trouble is, depending on the pH of the meal, this pigment can appear in a variety of hues. Blueberries or butterfly pea flower, for example, are an extremely alkaline meal with this pigment. That’s right, the purple-tinged blue tea.

A very acidic item, such as red onion or cherries, may appear red. Purple cauliflower, for example, is a middle ground or fundamental dish.

Some meals aren’t completely blue or red, and the purple might be bluish or reddish. Because the pH scale is a sliding scale rather than three fixed values, this is the case. It’s more of a matter of degrees.

Returning to anthocyanin, it appears reddish-purple in red onions because to the onions’ acidity. When anything alkaline (from the other end of the spectrum) comes into contact with this pigment, it turns blue. The bluer the food, the more alkaline it is.

This is also how pickled red onions get their lovely pinky tint. Because of the acid in the vinegar, the anthocyanin leans more towards red, resulting in the pink color you observe.

Is It Safe to Eat Blue Onions?

When it comes to red onions, even if they have gone blue, you may consume them. It’s merely their inherent color and how it responds to alkaline foods that causes the problem. If the onions upset you, you can try to get rid of them, although this may be difficult in many circumstances.

How Do You Know It’s Past Its Prime?

Feel for smoothness and firmness in entire onions. They’ve started to go bad if they have soft spots. If you have a slimy texture on a halved, chopped, or sliced onion, it has gone rotten. Smell – rotting onions have a foul odor.

How Can I Get Rid of the Blue?

You may reduce the blue by include acidic items in your diet. For example, if you’re cooking red cabbage and it’s becoming a bluish purple color, a sprinkle of vinegar will change it back to a pinkish red color.

Red onions or cherries can be used in the same way. The ultimate effect should be the same whether you use vinegar, lemon juice, or lime juice. We’re not sure about orange juice, but if you’re feeling really daring, it could be worth a try.

If you wish to restore the blue, add a pinch of baking soda and it will return to its original color. We’re not sure if it would be edible, but it would certainly affect the hue.

Is There Any Way to Stay Away from The Blue?

The only method to keep red onions from becoming blue is to avoid cooking with alkaline ingredients. No nuts, lentils, beans, legumes, egg white, red meat, leafy greens, or anything similar.

If you want to make chili con carne, simply use standard white or yellow onions! Unless you expose them to very acidic foods like vinegar or lemon juice, they will retain their original color. They’ll turn blue-green in such event. Chemistry, oh, chemistry!

If you have any other food-related questions, be sure to check out the linked articles below; we’re always adding more food facts to make your life simpler.

Read also: How Many Layers Does an Onion Have?

Final Words

Why Do Onions Turn Blue?

Onions’ pigment pigments act as a litmus test. The naturally acidic onion has a crimson hue. In alkaline conditions, they become green/blue. It sounds like the alkaline environment that caused the hue shift was formed when you cooked the beans.

Do red onions become green when cooked, other from what’s mentioned above? The pigments anthocyanin is abundant in red onions, as well as other red vegetables such as cabbage and cherries. When cooked with acid, their hue deepens, but when coupled with an alkaline ingredient, they can take on a stunning bluish-green hue.