While you are eating it, it is also eating you... After reading this, do you still dare to eat it directly?

Expert of this article: Fu Shufang, Master of Food Science and Nutrition Engineering, China Agricultural University, technician of the National Key Laboratory of Cardiovascular Diseases

Pineapple is a fruit that people both love and hate.

Love its sweet and sour taste, hate its "hard to swallow" taste.

There is a legend about it circulating in the world: when you eat it, it is also eating you...

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Why is pineapple so pungent? Is there any other way to enjoy pineapple besides soaking it in salt water? Yes, there is.

Why does pineapple prick your mouth?

The pineapple "mouth prickly" is mainly caused by bromelain and calcium oxalate needles.

Bromelain

Bromelain is a mixture of various proteases extracted from pineapples. It has the function of breaking down proteins. The main ingredient of the tenderizer we usually use is protease.

Bromelain can break down proteins in the oral mucosa, causing stinging and even bleeding.

In addition, bromelain can also trigger allergies in some people. Protease increases the permeability of the gastrointestinal mucosa, and large molecular foreign proteins in the gastrointestinal tract penetrate into the blood, causing allergic reactions in the body.

# If an allergic reaction is triggered, it is not as simple as "mouth pricking". In severe cases, it can lead to paroxysmal severe abdominal cramps, vomiting, diarrhea, itchy skin, numbness of the limbs and mouth and tongue, urticaria, conjunctival hemorrhage, and even dyspnea, shock and other reactions.

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Calcium oxalate needles

Calcium oxalate is a white crystalline powder that is insoluble in water, and calcium oxalate needles are a hydrated crystalline form of calcium oxalate.

Calcium oxalate needles are actually a weapon formed by plants during the evolution process to defend against herbivores. Pineapples, kiwis, spinach, etc. all contain calcium oxalate needles.

These tiny needle-like crystals can pierce the oral mucosa, so there is a pricking feeling in the mouth. Experiments have shown that when calcium oxalate needle crystals are added to applesauce, the applesauce will also feel pricking in the mouth.

Is it actually useless to soak in salt water to avoid getting your mouth pierced?

As we all know, soaking pineapple in salt water before eating it seems to make it less irritating to the mouth. What is the scientific basis for this?

We mentioned earlier that the main reason why pineapples prick your mouth is because of calcium oxalate needles and bromelain. The solubility of calcium oxalate needles in salt water will increase, so the content of calcium oxalate needles in some pineapples can be reduced.

The activity changes of bromelain are mainly affected by temperature, strong acids and alkalis, and heavy metals. Salt water does not completely inactivate the protease, but can partially inhibit its activity.

A study published in Food Science in July 2015 found that soaking pineapples in a 7% sodium chloride solution for 10 minutes effectively inhibited the activity of bromelain.

To reach a 7% concentration, 70 grams of salt should be added to 1 liter of water, which is actually a very large amount. Many people do not reach this concentration when soaking pineapples.

However, soaking in salt water can mask the sourness and bitterness of the pineapple, making it taste sweeter and better.

The easiest way to inactivate bromelain is actually high temperature. The protease can be inactivated above 60°C, so there is no prickly feeling in your mouth after the pineapple is cooked. Dishes such as pineapple rice, pineapple sweet and sour pork, and pineapple fried shrimps are all common pineapple delicacies.

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If you want to eat fresh pineapple, you can also try soaking it in hot water above 60℃ or heating it in the microwave for a short while, which can achieve the effect of not pricking your mouth and avoiding pineapple allergies.

Pineapples need to be soaked in salt water, but pineapples don’t?

There is also a saying on the Internet that "pineapples need to be soaked in salt water, but pineapples do not need to be soaked in salt water". What is the difference between pineapples and pineapples?

In fact, from a botanical point of view, pineapple and pineapple are the same plant, both belonging to the genus Bromeliaceae, and pineapple is a common name that gradually evolved later.

Merchants count pineapples and pineapples as two different fruits. The leaves of pineapples are not serrated and there are no internal thorns after peeling. However, pineapples can only be considered as different varieties of pineapple. In fact, they are cultivated "eyeless pineapples."

Pineapple does have a lower protease content and tastes sweeter, so it is less irritating to eat and can be accepted by most people without being soaked in salt water.

How to choose pineapple?

Having said so much about the importance of eating pineapples, let's take a look at some tips for choosing pineapples. You can observe from the following aspects:

Look at the color: a well-ripened pineapple is usually light yellow or bright yellow, and can be eaten immediately. The greener the color, the lower the maturity. If you want to keep it for a few days before eating, you can choose a light yellow with a slightly green luster, about 70% to 80% ripe.

Look at the leaves: Fresh pineapples are usually sold with leaves. Lush leaves indicate that the pineapple is in good condition. Pineapples without leaves may not be naturally ripe and may not taste good. In addition, varieties with long leaves generally taste sweeter.

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Feel the hardness: When buying a pineapple, you can gently press the pineapple with your hand. If it is hard and inelastic, it is not ripe and the taste is not good. If it feels slightly soft and elastic when pressed, the pineapple is ripe. However, if the skin is very soft when pressed, and even juice comes out, it may be overripe or rotten.

Smell: You can also judge the maturity of the pineapple by smelling whether the aroma is strong. Generally, a well-ripened pineapple can smell a distinct pineapple aroma, while an unripe pineapple has no smell. However, if the aroma is too strong or even smells like alcohol, it is overripe and is not recommended for purchase.

It seems

There is a scientific reason why pineapple is used as a side dish

How does microwaved pineapple taste?

You can try it

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