Garlic Turned Blue: Reasons/Factors/Is It Safe?

If you look back in history then you know that garlic was in use from the time when Giza pyramids were constructed, approximately 5000 years ago.

Garlic is generally used as a flavor in cooking, but it also has benefits related to medicine. It is used to prevent or stop many diseases. Garlic has some important properties of antibiotics.

I- Reason Of the Garlic Blue Color

Naturally, garlic enzymes give it a sharp taste that will break down the molecules over the period. Garlic color turns to blue when enzymes and amino acids that are always present in the garlic combine with sulfur compounds. It is the reason for the sharp smell of garlic when it changes to blue.

Due to the reaction, different substituents molecules are formed. These multi-pyrrole molecules produce different pigments. These molecules are most similar to chlorophyll that are present in plants.

Iodine in the common salt when reacts with the sulfur present in the garlic may change the color blue. Some garlic is naturally blue but can’t expose color until they react with acid like vinegar.


II- Factors that Involved In the Garlic Blue Color

Some factors are responsible for the change of the color of garlic to blue.

1- Garlic Age

Some sources said that the newly harvested garlic that is rich in water content has more liability to turn the color. Also if the garlic is picked before it is fully grown up then there is a chance that garlic turns blue.

Garlic age has been determined that all in the compound is present in how much amount, also tells the nature of enzymes.

2- Presence Of Acid

It is also noted that the presence of acid like lemon juice and vinegar may change the garlic color to blue, however, this will not always happen. Whenever garlic is cooked with an acidic substance, a color change will happen.

3- Temperature Of The Surroundings

Garlic that is heating up before use, has the chance to change the color either react with acid or not. pH also affects garlic. pH is a chemical reaction that occurs at the molecular level. When we change the pH level the compound anthocyanin turns to blue color.

Garlic also turns blue because of the condition of the soil in which it grows. 

If the soil is acidic, then there is more liability of blue color. However, anthocyanin is rich in the soil in some garlic fields that change the color even when the pickling process is started.

4- Garlic Bulbs

There are different colors of garlic cloves or bulbs like some are white, some are purple or pink, sometimes it is pink. So the colored garlic has more liability to turn blue.

III- Raw Garlic Turns Blue

There are biologically active materials present in garlic cells that have sulfur compounds. These sulfide compounds make different substances like thiosulfinate, allylic thione in the presence of enzymes. So the originator of the garlic pigment like sulfonate makes a reaction series. At the start of the reaction, garlic pigment changes the color blue and after that, it will change other colors like green, yellow, etc.

IV- Garlic Turns Blue when Pickled

In garlic pickles, sometimes garlic turns blue because of vinegar ( acid ) added to it. Vinegar damages the cell membranes of the garlic cloves. Amino acid and sulfur react with each other and mix with acid, and turn the garlic blue.

V- Garlic Turns Blue In Vinegar

As we know that there is odorless compound sulfur called allicin is present in garlic and it contains enzymes alliinase. Whenever the garlic reacts with an acid like vinegar, allicin combined with amino acids produces the rings of a carbon-nitrogen compound called pyrroles which are responsible for the color change to blue.

VI- Garlic Turns Blue When Cooked

If you are cooking in the copper utensils then the sulfur in garlic reacts with the copper to produce a compound of copper sulfate. It is a compound with a blue-green color.

So when we cook the garlic in copper utensils it will turn to blue color, but it is still safe to eat because when we heat the garlic it will not remain harmful for food.

VII- Is Blue Garlic Edible

Sulfur that is present in garlic interacts with enzymes and gradually turns the color of garlic blue or green. Although the color change has not any effect on the taste. So, if the garlic turns blue, it should be okay because it is still edible.

If you can not find the presence of any microorganisms like bacteria, fungi, or any foul smell then you can eat the garlic if it is blue. 

In China, colored garlic is used for pickling or cooking. Because color has not any effect on the taste of the food. Its taste is sour and a little spicy.


VIII- Conclusion: Garlic Turned Blue

Although, if we will give the heat continuously then the garlic color may turn blue to pinkish brown. Blue garlic can not turn to white. So if you want to avoid the color change, use fresh garlic.

If you want to avoid that then use the utensils of stainless steel. Also, some kinds of garlic have a blue color when they react with acid elements.

Also, use common salt instead of iodine. Garlic turns blue while stored for a long period. However, blue garlic is not considered the problem of pickling; it occurs whenever we cook garlic in an acidic solution.

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Adila Zakir

Adila Zakir (USA Federal Drug Authority Certified) Studied medical and medical-related business at the same time Overcame search lethargy Worked for medical search and business marketing consultation Expert in medical writing and has special interest in immunity boosting foods.

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