From the plant taxonomic comparison, grapefruit and China's native grapefruit is very similar. Both belong to the same genus Citrus (Citrus), just grapefruit shoots, leaf back, pedicels, sepals and ovaries are hairy, seeds with a single embryo, the distance between the fruit is obvious, not a string; and grapefruit all parts of the whole plant are glabrous, seeds with multiple embryos, the fruit than grapefruit small skin is thinner, and often more fruits into bunches, similar to the grapes, so which the English name of the grapefruit are called grapefruit (grape fruit). From the phytochemical analysis, grapefruit chemical composition of many of the original belong to the grapefruit class. Its flowers and rind containing chemical composition and grapefruit a few no difference, the main flower containing methyl phthalate, nerol and decanol. The rind mainly contains limonene (about 90%), the rest for citral, citronellol and octanol, and contains flavonoids naringin. From the cell chromosome number control, grapefruit chromosome number X = 9, 2n = 18, 27, 36, that is, there are diploid, triploid and tetraploid varieties. Whereas, grapefruit had chromosome number X=9, 2n=18, 36, i.e. only diploid and tetraploid varieties. The comparison of these traits clearly indicates that the American grapefruit is undoubtedly a variant (e.g., budburst) or hybrid of the Chinese grapefruit Citrus macima (Burm) Merr. This shows how closely related the two citrus plants are.
The genus Citrus was established in 1753 by the famous Swedish botanist Linnaeus, and the official Latin scientific name Citrus was published. In fact, the world's first citrus monograph is China's Southern Song Dynasty scholars Han Yanzhi prepared, *** accounted for the time of the middle and lower reaches of the Yangtze River around the citrus and kumquat genus (including varieties) 27. The book was published in 1178, nearly 600 years before Linnaeus. So far, it is known that there are about 20 species of citrus plants around the world ***, tropical and subtropical regions are often cultivated, about 15 species in China. Citrus plants originated in southeastern and southern Asia, China is undoubtedly one of its origins, especially in the Three Gorges region of the Yangtze River, which has been known as the "home of citrus" since ancient times. Qu Yuan, the great patriotic poet of the Warring States period, in his hometown of zigui county, hubei province, had created the immortal song "orange song", still in the north and south of the river is widely praised. In the past 20 years, Yichang in Hubei Province every year to organize a grand "International Citrus Festival" that is clear evidence. Although according to the literature, grapefruit was first found in the West Indies, but from the composition of the flora and phytogeography, the natural distribution of citrus plants will not be to the Americas, the origin of its relatives should be in Asia, tracing its roots, probably from our country. American grapefruit's hometown in China, logical and undoubted.
Currently, the market common grapefruit has three main varieties. Flesh white Marsh grapefruit (Marsh), also known as nuclear grapefruit, is a polyploid, varieties within the flesh of red strains; flesh white Duncan grapefruit (Duncan), fruit is larger, thicker skin, more seeds, flesh slightly bitter; flesh red Thompson grapefruit (Thompson). In addition, there are also varieties with yellowish or pinkish or nearly colorless transparent flesh.
Grapefruit flesh tender, juicy and crisp, slightly fragrant, taste acidic, bitter and tongue taste. Its juice is slightly bitter, but the taste is comfortable, about half of the world's grapefruit is processed into juice. Grapefruit and its juice in North America, European countries and Japan, is a lot of family breakfast essential fruit and beverage, has become an important agricultural product in the consumption of citrus fruits, second only to sweet orange (orange). Especially in the upper class and white-collar workers in Western countries, to eat grapefruit as a taste, and few people ask for sweet oranges, which are suitable for both young and old. Therefore, eating grapefruit, drinking grapefruit juice has become fashionable, in general people think it is a cool thing (cool). In fact, the cool here, there is a layer of "bitter" meaning. At present, the West is popular in a new dietary concept, is to eat "bitter", or cool to eat, and no longer eat "sweet". Nutritional knowledge warns people, eat more desserts easy to get fat, and will induce cardiovascular disease, diabetes and fatty liver and many other diseases. And moderate consumption of bitter fruits and vegetables and beverages, such as bitter melon, celery and bitter tea, etc., can clear the mind and eyes, diuretic and blood pressure, beneficial to health.
Hypertensive patients often take antihypertensive drugs to eliminate excess sodium in the body to maintain the body's normal biochemical metabolic balance, but at the same time often make the body necessary loss of potassium; and potassium for the maintenance of the heart, blood vessels, the function of the kidneys, is very important. Grapefruit contains potassium, but does not contain sodium, and also contains natural pectin that can lower blood cholesterol, so it is the best therapeutic fruit for patients with high blood pressure and cardiovascular disease.
Grapefruit contains valuable natural vitamin P and is rich in vitamin C and soluble fiber. Vitamin P can enhance the function of the skin and pores, which is conducive to skin health and beauty. Vitamin C can participate in human collagen synthesis and promote the production of antibodies to enhance the detoxification function of the muscle.
In addition, grapefruit can also help the body absorb calcium and iron, which are two important minerals necessary to maintain the normal metabolism of the body. Grapefruit also contains natural folic acid, which prevents anemia in pregnant women and reduces the chances of having a deformed baby.