Taxonomically, grapefruit is very similar to grapefruit native to China. Both of them belong to the genus Citrus, except that the shoots, leaves, pedicels, sepals and ovaries of pomelo are hairy, the seeds are single embryo, the distance between fruits is obvious, and they are not beaded. Grape fruit is hairless in all parts of the whole plant, with many embryo seeds, thinner skin than grapefruit, and many fruits are often strung like grapes, so its English name is grapefruit. According to phytochemical analysis, many chemical components of grapefruit belong to the original grapefruit. The chemical composition of its flower and peel is almost the same as that of grapefruit, and the flower owner contains methyl o-aminobenzoate, nerol and decanol. The pericarp mainly contains limonene (about 90%), the rest are citral, citronellol and octanol, and also contains flavonoids naringin. Compared with the cell chromosome number, the chromosome number of grapefruit is X=9, 2n= 18, 27, 36, which means there are diploid, triploid and tetraploid varieties. The chromosome number of pomelo is X=9, 2n =18,36, which means that there are only diploid and tetraploid varieties. The comparison of these characters clearly shows that American grapefruit is undoubtedly a mutant (such as bud mutation) or hybrid of Merr of China grapefruit (Burm), which shows how close the genetic relationship between the two citrus plants is.
Citrus was founded by Linnaeus, a famous Swedish botanist, in 1753 and officially named Citrus in Latin. In fact, the world's first monograph on citrus was written by Han Yanzhi, a scholar in the Southern Song Dynasty, which recorded 27 kinds of citrus and kumquat plants (including varieties) in the middle and lower reaches of the Yangtze River at that time. This book was published in 1 178, nearly 600 years before Linnaeus. Up to now, there are about 20 species of citrus plants in the world, which are often cultivated in tropical and subtropical regions, and there are about 15 species in China. Citrus originated in Southeast Asia and South Asia, and China is undoubtedly one of its origins, especially in the Three Gorges area of the Yangtze River, which has been known as the "hometown of citrus" since ancient times. Qu Yuan, a great patriotic poet in the Warring States Period, wrote an immortal song Ode to Orange in his hometown of Zigui County, Hubei Province, which is still widely sung in the north and south of the Yangtze River. In recent 20 years, Yichang, Hubei Province has held a grand "International Citrus Festival" every year. According to the literature, grapefruit was first discovered in the West Indies, but from the flora composition and phytogeography, citrus plants will not naturally distribute to America, and their parents should have originated in Asia, probably from China. There is no doubt that the hometown of American grapefruit is in China.
At present, there are three main varieties of grapefruit on the market. Swamp grapefruit with white pulp, also known as seedless grapefruit, is polyploid, and there are also strains with red pulp in the varieties. Duncan grapefruit with white flesh has large fruit, thick skin, many seeds and slightly bitter flesh. Red meat Thompson. In addition, there are varieties whose flesh is pale yellow or pink or almost colorless and transparent.
Grapefruit pulp is soft, juicy and refreshing, with faint aroma, sour taste, bitter taste and hemp tongue taste. Its juice is slightly bitter, but it tastes comfortable. About half of the grapefruit in the world is processed into juice. Grapefruit and its juice are essential fruits and drinks for breakfast in many families in North America, European countries and Japan, and have become an important agricultural product with consumption second only to citrus. Especially in the upper class and white-collar workers in western countries, eating grapefruit is a taste, and few people care about sweet oranges suitable for all ages. So eating grapefruit and drinking grapefruit juice became fashionable for a while, which is a cool thing for ordinary people. In fact, the coolness here has another meaning of "bitterness". At present, a new concept of diet is popular in western countries, which is to eat "bitter" or "cold" instead of "sweet". The knowledge of nutrition warns people that eating more desserts is easy to get fat, and it can also induce cardiovascular diseases, diabetes and fatty liver. And moderate consumption of bitter fruits, vegetables and drinks, such as bitter gourd, celery, kudingcha, etc., can clear the heart and improve eyesight, promote diuresis and lower blood pressure, which is beneficial to health.
Hypertension patients often take antihypertensive drugs to eliminate excess sodium in the body to maintain normal biochemical metabolism balance, but at the same time, it often causes the loss of essential potassium in the body; Potassium is very important for maintaining the functions of the heart, blood vessels and kidneys. Grapefruit contains potassium, but does not contain sodium, and also contains natural pectin which can lower cholesterol in blood, so it is the best slimming fruit for patients with hypertension and cardiovascular diseases.
Grapefruit contains valuable natural vitamin P, rich vitamin C and soluble cellulose. Vitamin P can enhance the function of skin and pores, which is beneficial to skin care and beauty. Vitamin C can participate in the synthesis of human collagen, promote the production of antibodies and enhance the detoxification function of the body.
Grapefruit can help people absorb calcium and iron, which are two important minerals necessary to maintain normal metabolism. Grapefruit also contains natural folic acid, which can prevent anemia in pregnant women and reduce the chance of giving birth to deformed babies.