We all know that lemons are acidic because they contain acid. Addition of ascorbic acid (vitamin C), this citrus contains citric acid, salts and esters which called citrates.
For the first time in its pure form citric acid was isolated by the Swedish chemist Carl Wilhelm Scheele in 1784. This turned the white crystalline solid which is readily soluble in water and has a sour taste.
Acid itself, as its salt (sodium citrate, potassium citrate, calcium citrate), is now widely used as a flavoring agent, acidity regulator and the preservative in the food industry. Food additives: E330 (citric acid), E331-E333 (citrate).
The presence of acids explains why sour lemons, and the project description the author asked the question "Why" lemon sour be? "What is the biological expediency that sour lemon? Go back to the description of the project and consider the question of the author.
I propose to discuss this together! Dear participants of the project, to express their suggestions in the comments. I advise you to refer to the information resources of the Internet. But remember, please, that before using the information necessary to verify its authenticity (the project "Information Security" ). While recording in the comments, please indicate why you practice this or that opinion. Why do you trust the information you used?
We continue to work on the project! Examine the mandarins. What is the level of acidity of the citrus fruits that have been grown in different countries? Does the taste and the result of measuring the acidity of the juice?
On the palate the most sweet tangerine turned from Turkey. But look at the result of our research:
Remember that the smaller the value of the pH, the acidity of the above. And according to our results it appears that the most sweet mandarin had to be from Abkhazia! And he (we got a randomly for the study) tasted very sour ...
Dear participants of the project, the Express, please your opinion on this issue. Why is the result of measurement of acidity and taste gave different results?
With the onset of winter cold increases the number of people who suffer from colds, and the possibility of a flu epidemic. To prevent the disease or improve during his illness, is often recommended to eat more citrus. Hot tea with lemon - the first remedy for colds. On what evidence based recommendations from the scientific point of view?
Medicinal properties of citrus fruits were discovered in the middle of the XVIII century Scottish ship's surgeon James Lind discovered that citrus property prevent the outbreak of scurvy. At that time it was very important, because in the Age of Discovery, going on a long voyage, people were dying of scurvy, although stocks corned beef and biscuits were on the ships in abundance. For example, of the 160 members of the expedition of Vasco da Gama, paves the sea route to India, from scurvy killed 100 people.
In 1753, Lind published the results of his discovery, but only in 1800 in the UK, it was decided to have on board each ship stock limes. Since then, the British on all the seas became known as limeys (from Eng. Lime - lime).
It turned out that the healing properties of citrus caused by vitamin C or ascorbic acid, and for the first time in its pure form, this vitamin has been isolated in 1927 SS Silvia of lemon juice.
It is proved that vitamin C is involved in many important redox processes in the body cheloveka.Etot vitamin promotes the formation of proteinaceous material, which strengthen the immune system. That is why during the flu epidemic body is able to resist infection.
In addition, vitamin C affects the quality of the blood: First, a protective effect on the hemoglobin by preventing its oxidation; secondly, helps to maintain a reserve of iron in the body. Vitamin C also regulates blood coagulation and normalizes permeability of capillaries, which helps to improve the cardiovascular system. Another very important fact that vitamin C involved in cholesterol metabolism, normalizing blood levels.
The scientists found that vitamin C is a factor in protecting the body from the effects of stress. In times of stress in the body, intensive production of hormones - such as adrenaline. Vitamin C is involved in the processes that contribute to reduce the level of this hormone. Therefore, it is especially necessary for us to make it easier to overcome stress.
Our body can not store vitamin C, so you need to constantly get him further from food. Because it is water soluble and exposed to a temperature in the cooking process by thermal treatment of vitamin C destroyed. It is therefore important to eat foods that contain vitamin C and do not require heat treatment. For example, citrus fruits.
But not only vitamin C is an essential component in citrus fruits. There are a number of substances of very useful for our body. What? I propose to discuss them in the comments.
Thanks to the author of the project! The original idea of the study citrus acidity allowed in class to solve a lot of problems! The boys learned to work with digital sensors, dealt with the concept of "acidity" (pH), analyzed the data research tool. And the results of the project were interested students throughout the school.