The second question:
Lemon contains natural citric acid and citrate (calcium citrate, potassium citrate, etc. )
After eating lemon, the natural citric acid is all organic after primary metabolism, and the acidity and alkalinity are ignored!
Citrate is alkaline because it will generate other acid-base inorganic components or alkaline salts (alkaline) after biochemical reaction.
These are well understood biochemically, but they are not recognized without contact with biochemistry.
Na _ 2 HCO _ 3 is an alkaline salt and Na2HCO3 _ 4 is an acidic salt.
Reference:
Is lemon acidic or alkaline?
From the point of view of chemistry or food science, whether food is acidic or alkaline may be very different. Is lemon acidic or alkaline? Most people think that sour people are acidic. But from the perspective of food science, lemon belongs to alkaline food.
Why? Food will become alkaline after entering the human body, so we classify it as alkaline food. For example, after lemon juice enters the human body, it will be oxidized and burned into carbon dioxide and water, and the rest will become inorganic substances. We can determine whether it is an alkaline food or an acidic food by looking at what is in its inorganic matter.
If the content of sodium, potassium and calcium is high, it will become alkaline food. Because sodium and other compounds become alkaline when dissolved in water.
Sodium carbonate+H2O->; sodium bicarbonate
Bicarbonate-+H2O->; H2CO3 + OH-
2(Na+)2O22- + 2H2O ->4Na+OH- + O2
Ah ... where are the sodium carbonate and sodium peroxide? Nutritional biology in junior high school tells us that food will be burned (digested) by a complex oxidation. Chemists simulate the digestion process of food to determine its pH value.
1. Burn food to ashes
2. Dissolve the ashes with solvent
3. Test the pH value of the ash solution
On the contrary, if the content of phosphorus, sulfur and chlorine is high, it will become acidic food.
So what is the correct answer? From the fact that lemon juice turns red when applied to litmus paper, we can know that lemon is really acidic. Different opinions, when you know whether a substance is acidic or alkaline, the result will be different, so be careful!
Lemon can also expectorate, and its expectorant effect is stronger than that of oranges and citrus. Add warm water and salt to lemon juice, drink it and cough up the thick phlegm accumulated in your throat. It is very effective. At the beginning of a cold, you might as well wash it with lemon and honey, which can relieve sore throat and relieve the discomfort of dry throat.
Lemon drink, lemon juice and lemon honey all have their own curative effects, and lemon tea is almost the same. It's not that lemon tea is invalid, but that black tea is brewed at high temperature. The effective component catechin in tea was destroyed, but the harmful substances increased. Moreover, tannic acid and citric acid in tea are quite acidic, and people with stomach diseases had better avoid drinking them, but for those with stomach diseases, a cup of lemon tea after meals can really help digestion.
To some extent, lemon can be said to be a female fruit, because it can give birth to babies, so it is called "suitable for mother and child". It can also be used for beauty, because its citric acid can remove spots and prevent pigmentation, which can be taken orally or externally. More domestic studies have pointed out that lemon can improve uterine anteversion, uterine ligament prolapse and even amenorrhea.
Lime can lower blood pressure and cholesterol and improve cardiovascular disease. Like grapefruit, it contains an insulin-like ingredient, so eating it can lower blood sugar, which can be said to be a wonderful "medicine" for fruit.