Small problems in life, want to find experts to answer?
Dr. Lilac's "Special Treatment" is launched at 9:00 every morning, inviting doctors and experts in the field of health to give professional answers to daily confusion.
If you don't understand life problems, remember to ask the experts~
Recently, a reader asked a question in a private message:
I bought a glass of ice lemonade before, and it was a sliced fresh lemon, and I didn't feel anything at first, but after a long time (about two hours), I found that it became bitter, and the longer I put it, the more bitter it became!
Why is that?
It's a very interesting question, and to answer it, we must first start with the taste of lemon.
Lemon endothelium has a bitter taste
In fact, lemon is really a magical food, and each part of it has a very different sensory experience.
Let's take a sliced lemon as an example:
Image source: Courtesy of the author
The first layer, the outer skin of the lemon, is the outermost yellow part. It contains a lot of essential oils, and most of the lemon aromatic taste comes from this. In Western food, the outer skin is carefully cut off, cut into thin strips or minced pieces, and added as a seasoning to the dish to increase the lemon flavor. Such a seasoning is called Lemon zest (citrus peel).
The second layer, the inner skin of the lemon, is the outer skin, the outer flesh, the white layer. This layer is very bitter. It is sometimes placed in special cocktails specifically designed to add bitterness.
The third layer, the pulp of the lemon, is the main source of the sour taste of the lemon, but also contributes a part of the aroma of the lemon.
The outer rind of the lemon is fragrant, the inner rind is bitter, and the pulp is sour. Three completely different parts can coexist in the same fruit, which is why lemonade lemon tea is always so sour and can't stop.
Now back to the opening question, the answer is simple: lemon slices soaked in water for a long time, the bitter substances in the lemon endothelium will dissolve into the water, making the whole lemonade bitter.
Cold water soaking lemons is not easy to be bitter
The bitter substances of lemon endothelium are collectively referred to as limonoids (limonin compounds), the most common of which is Limonin (limonin), a highly oxidized tetracyclic triterpenoid compound containing a furan ring.
Limonin is not only present in the inner epidermis of lemons, but also in high levels in lemon seeds.
When making lemonade, you should also pay attention to removing the seeds, which can minimize the bitterness.
Limonin (Limonin)
If you soak lemons in hot water, the bitter substances will dissolve faster and lemonade will become more bitter.
You may ask, when I made lemonade before, it seemed that I had not been bitter for a long time. In fact, this is also related to the type of lemon, because some lemons have more bitter substances in the inner skin, and some have less.
The key to not making lemonade bitter:
Soak the lemon in cold or ice water
Choose the kind of lemon that is not too bitter in itself and is suitable for lemonade (try a few more lemons to find out your favorite flavor)
Audit Expert Registered Dietitian, Master of Nutrition from Columbia University Jiewen Li
Content planning meals
Eric, head of the column
Next issue is coming soon
Tomorrow morning, "monopoly does not understand", we will explain the "precocious puberty" related problems for everyone, friends with the same life troubles do not miss Oh ~ ~