vitamin
It plays an important role in regulating human physiological function and ensuring health. Fruits rich in vitamin C (ascorbic acid) include Rosa roxburghii, Kiwi, jujube, hawthorn, citrus, strawberry and avocado. Some fruits are rich in carotene (source of vitamin A), among which apricot, loquat and busy fruit are more, followed by plum, cherry, hawthorn and citrus. Fruits containing vitamin B 1 and B2 are avocados, busy fruits, bananas, sweet oranges, walnuts and chestnuts. In addition, some fruits also contain vitamin P, vitamin D, vitamin E, folic acid and so on. Vitamins are often lost during thermal processing, especially vitamin C, which is the most unstable. Therefore, fresh fruit has become an important food to supplement many vitamins needed by human body.
Minerals and trace elements
Fruit contains calcium, phosphorus, potassium, iron and other mineral elements, and is an important part of human tissues. Inorganic salts can regulate the osmotic pressure of cells and maintain the acid-base balance in the body, some of which are components of various enzyme systems. Some fruits are particularly rich in minerals, such as olives, almonds, hazelnuts, almonds, loquat, hawthorn, Rosa roxburghii, citrus and so on. Hazelnut, almond, almond and walnut are rich in phosphorus; Pistachio nuts, hazelnuts, almonds, cherries and almonds are rich in iron; Almonds also contain trace elements such as manganese and zinc.
carbohydrate
It is the main component of fruit, including sugar, starch, cellulose and pectin. The sugars in fruits are mainly glucose, fructose, sucrose and maltose. Most fruits contain a lot of glucose, especially grapes, followed by cherries, plums, apricots, persimmons and cranberries. Fructose and glucose are monosaccharides, which are easily absorbed by human body. Fruits with high fructose content include apples, pears, grapes and cherries. Fruits containing more sucrose are peaches, apricots, plums, longan, raspberries and apples. Maltose is found in grapes, raisins and blackberries. The content of starch in mature fruits is very small, but it is more in figs, longan, busy fruits, chestnuts and other fruits. Starch can be decomposed by enzymes in human body, converted into maltose, and finally converted into glucose and absorbed.
In addition to sugar and starch, fruit also contains more cellulose and pectin, which can not be digested and absorbed, but can promote intestinal peristalsis, enhance gastrointestinal function and relieve constipation. After being decomposed by intestinal microorganisms, it also has the function of reducing the harm of toxic substances to human body. Pectin, for example, can accelerate the excretion of lead in the body and reduce the cholesterol content in the blood. Pectin and cellulose can adsorb bacterial toxins, have antidiarrheal effect and help prevent atherosclerosis.
organic acid
It can enhance fruit flavor, promote digestion and maintain acid-base balance of human body. The main types of organic acids in fruits are malic acid (apple, pear, peach, cherry, plum, etc. ), citric acid (citrus, pomegranate, banana, pineapple, raspberry, etc. ) and tartaric acid (grapes, apples, cherries). There are also oxalic acid (apricot and cranberry), succinic acid (cranberry and gooseberry), isocitrate (cranberry), quinic acid (cranberry and pear), fumaric acid (gooseberry and apple) and so on. A fruit usually contains several organic acids.
Protein, fat and enzymes.
Generally, there are few nitrogen-containing substances (protein, amino acids and fat) in fruits, but some dried fruits, such as walnuts, hazelnuts, almonds, almonds, torreya grandis and coconuts, are rich in protein and fat. Fruit also contains a variety of enzymes, which is of great significance to the metabolism of various substances in the human body; They also have an impact on the ripening, quality and storage of fruits. The main enzymes are oxidase, peroxidase, catalase, amylase, protease, sucrase, lipase and pectinase, all of which have direct or indirect effects on human nutrition.
In addition, the fruit also contains various pigments, tannins and aromatic substances. Chlorophyll, carotenoids, flavonoids and anthocyanins make fruits have different colors. Tannic acid makes fruit astringent. Aromatic substances are mainly complex organic compounds such as esters, ethers, aldehydes and ketones, which make fruits have special fragrance. These substances that determine the color, aroma and taste of fruits also directly or indirectly affect the nutritional value of fruits.
The contents of main nutrients in various dried and fresh fruits are shown in the table.
Nutrient content of edible parts of various fresh fruits per100g; The health care function of fruit.
Fruits also contain some ingredients with medicinal functions, which have medical and health care functions. Some fruits are Chinese herbal medicines with great medicinal value. Vitamins A, C, catechol and flavonoids contained in apricot fruit and amygdalin contained in almond have the functions of dilating trachea, diminishing inflammation and relieving cough. Triterpenoids and flavonoids contained in hawthorn can regulate heart rhythm, prevent coronary heart disease and lower cholesterol; It contains Sophora flavescens, hyperoside, etc. It is effective for tracheitis. Kiwifruit is rich in vitamin C, vitamin P and linoleic acid contained in seeds, which has a certain effect on preventing cardiovascular diseases and lowering cholesterol. Siraitia grosvenorii contains a special sweet substance, which is 300 times sweeter than sugar and suitable for diabetics. Rosa roxburghii fruit is rich in vitamin C, with 842 ~ 3500 mg per 100 g fruit. Drinking Rosa roxburghii juice regularly can prevent nervous system diseases and visceral tumors. Seabuckthorn is rich in vitamins C, E, A, PP and nicotinic acid, which can soften blood vessels, lower blood pressure and prevent the formation of carcinogens in human body.